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Silicon/carbon (Si/C) nanocomposites are considered as one of the most promising anode materials for lithium-ion batteries due to their high capacity and suitable lithiation potential. However, the complex and time-consuming preparation processes of silicon-based nanocomposites and the unexpected silicon carbide generated during high treatment make it difficult to achieve high-performance Si/C nanocomposites for practical applications. Herein, a silicon/carbon nanocomposite is successfully prepared through a facile and eco-friendly molten salt assisted precarbonization–reduction method using palygorskite (PAL) and sodium alginate as raw materials. Based on physical characterizations, it is demonstrated that the sodium alginate plays a key role in the successful preparation of Si/C nanocomposite, which not only boosts uniform embedding of PAL nanoparticles in the carbon matrix but also releases molten sodium salt to suppress the formation of unexpected SiC. When used as an alternative anode material for lithium-ion battery applications, the as-obtained Si/C composite delivers a high reversible specific capacity of 1362.7 mA h g−1 with an initial Coulombic efficiency of 70.3% at a current density of 200 mA g−1 and excellent long-term cycling stability. The findings here provide a facile and eco-friendly molten salt assisted precarbonization–reduction method for high-performance silicon/carbon anode materials. [ABSTRACT FROM AUTHOR]

Tiny NiSnO3 nanoparticles with the assistance of polyvinylpyrrolidone (PVP) are prepared to uniformly and stably "bond" on the surface of graphene to form a stable NiSnO3/RGO-PVP structure. At the same time, the excellent performance of lithium-ion batteries (LIBs) with the use of NiSnO3/RGO-PVP structure is verified through a dual combination of experiment and theory. The resulting NiSnO3/RGO-PVP structure enhanced the performance of LIBs with high cycling stability and better rate capability; even after undergoing rate performance tests at different high current densities, the NiSnO3/RGO-PVP electrode can still reach a capacity of 624 mA h g−1 at 200 mA g−1 after 400 cycles. The superior electrochemical performance of NiSnO3/RGO-PVP nanocomposites can be attributed to the synergistic effects between tiny NiSnO3 nanoparticles synthesized with the assistance of PVP and RGO, which can be verified through first-principles calculations based on DFT. The charge transfer between NiSnO3 and RGO through an electron density difference indicates a strong interaction between the two. Meanwhile, the low adsorption energies (−3.914, −0.77, and −0.65 eV), low diffusion barriers (0.025, 0.49, and 0.141 eV), and high diffusion coefficients (1.79 × 10−3, 5.38 × 10−11, and 2.97 × 10−5 cm2 s−1) of lithium ions at three different positions indicate the excellent rate performance of the NiSnO3/RGO-PVP heterostructure, which is consistent with experimental results. This work analyzes the excellent electrochemical performance of NiSnO3/RGO-PVP from the experimental results and supports the reliability of the experimental results through theoretical calculations. [ABSTRACT FROM AUTHOR]

Metal–Organic Polymers (MOPs) have attracted growing attention for lithium-ion battery (LIB) applications due to their merits in orderly ionic transportation and robust structure stability in electrochemical reactions. However, they suffer from poor electronic conductivity. In this work, we apply first-principles density functional theory to explore the potential of three one-dimensional (1D) electrically conductive C6H2S4TM (TM = Fe, Co, and Ni) MOPs with the π–d conjugated coordination as anode materials for Li+ ions storage. Our theoretical results reveal that these 1D MOPs possess a superior theoretical capacity of over 748 mA h g−1. In particular, the 1D C6H2S4Ni MOP shows an exceptional theoretical specific capacity of 1110 mA h g−1 based on the three-electron transferring reaction, which significantly outperforms the traditional graphite-based anode material in LIBs. Moreover, the resonant charge transfer between Ni metal and ligand within the 1D C6H2S4Ni MOP reduces the diffusion energy barrier of the Li atoms when they migrate on the surface of the MOP. The ultrahigh theoretical specific capacity of the C6H2S4Ni MOP predicts that it can be a promising anode material for LIBs. [ABSTRACT FROM AUTHOR]

Disordered rocksalt cathodes exhibit high specific capacities and high energy density; however, their low electronic conductivity poses a great challenge. Herein, we explored an aqueous-solution-based synthesis route that involves controlling the surface charges of Li1.2Mn0.6Ti0.2O1.8F0.2 (LMTOF) to be anchored by a few-layer reduced graphene oxide (rGO) for the first time. The uniform rGO wrapping on the surface of the LMTOF particles is achieved by electrostatic attraction between the negatively charged rGO and positively charged LMTOF particles. Although the initial specific capacity of rGO-LMTOF composite increased by 58 % compared to the pristine LMTOF, the composite experienced a severe capacity fade over cycling. The synthesis process in an aqueous medium resulted in Li+/H+ exchange and TM dissolution as evidenced from inductively coupled plasmon analysis and X-ray diffraction analysis. Therefore, this work suggests the search for alternative media or conditions for the synthesis of carbon-disordered rock salt cathode composite.

This study presents a novel approach to developing high-performance lithium-ion battery electrodes by loading titania-carbon hybrid spherogels with sulfur. The resulting hybrid materials combine high charge storage capacity, electrical conductivity, and core-shell morphology, enabling the development of next-generation battery electrodes. We obtained homogeneous carbon spheres caging crystalline titania particles and sulfur using a template-assisted sol-gel route and carefully treated the titania-loaded carbon spherogels with hydrogen sulfide. The carbon shells maintain their microporous hollow sphere morphology, allowing for efficient sulfur deposition while protecting the titania crystals. By adjusting the sulfur impregnation of the carbon sphere and varying the titania loading, we achieved excellent lithium storage properties by successfully cycling encapsulated sulfur in the sphere while benefiting from the lithiation of titania particles. Without adding a conductive component, the optimized material provided after 150 cycles at a specific current of 250 mA g-1 a specific capacity of 825 mAh g-1 with a Coulombic efficiency of 98%.

To find a novel resin to remove Co(II), the adsorption behaviour of Co(II) from the simulated acid leaching solution was investigated by ion exchange with AG®50W-X4 resin. Parameters such as reaction time, HCl concentration, and resin concentration affected the loading efficiency of Co(II) by AG®50W-X4 resin were tested. The adsorption behaviour of Co(II) strongly depended on HCl and resin concentration while reaction time was little effect on the loading percentage of Co. The loading behaviour of Co(II) into the resin fitted well with the Langmuir adsorption isotherm and the loading capacity for Co(II) was found at 29.8 mg/g. Moderate HCl solution was effective in eluting Co(II) from the loaded AG®50W-X4 resin. The obtained results investigated that AG®50W-X4 resin was a promising resin to absorb Co(II) from the low acid leaching solution of the spent lithium-ion mobile phone batteries. [ABSTRACT FROM AUTHOR]

Novel bismuth oxide/sodium bismuth molybdate nanocomposites (NCs), Bi 2 O 3 @NaBi(MoO 4) 2 , were developed successfully via simple methods. Advanced analyses revealed that the NCs were composed of Bi 2 O 3 and NaBi(MoO 4) 2 particles at the nanoscale, below 10 nm, in a combination of amorphous and crystalline forms. In this work, these NCs were utilized as lithium-ion battery anode materials for the first time, demonstrating exceptional electrochemical performances, including high capacity, superior capacity retention, high coulombic efficiency, excellent rate capacity, and pseudo-capacitance behavior. For instance, Bi 2 O 3 @NaBi(MoO 4) 2 NCs prepared at 1 h and 3 h of reaction time delivered a reversible charge capacity of 1052 and 1034 mAh g−1 after 200 cycles at current densities of 0.1 A g−1 with a capacity retention of 110 and 129 %, respectively. Notably, all the NCs anodes exhibited an excellent initial coulombic efficiency of above 80 %. Materials characterizations and electrochemical analysis revealed that the improved electrochemical properties of the NCs were attributed to their unique architectures, which featured nanostructures, molybdate components, and a small amount of amorphous phase. In addition, the significant capacity increase could be due to the electrochemical milling effect, the in situ formation of metallic particles, and the role of Mo metal in the NCs anodes as the catalysts for Li 2 O decomposition during cycling. It concluded that Bi 2 O 3 @NaBi(MoO 4) 2 NCs have great potential as advanced anodes for Li-ion storages. [Display omitted] • Bi 2 O 3 @NaBi(MoO 4) 2 materials are prepared via facile methods. • Bi 2 O 3 @NaBi(MoO 4) 2 materials consist of both amorphous and crystalline structures. • Bi 2 O 3 @NaBi(MoO 4) 2 materials are comprised of a lot of nanoparticles below 10 nm. • Bi 2 O 3 @NaBi(MoO 4) 2 anodes exhibit high initial coulombic efficiency (>80 %). • Bi 2 O 3 @NaBi(MoO 4) 2 anodes demonstrate a fast and stable Li-ion storage ability. [ABSTRACT FROM AUTHOR]

This review discusses five distinct types of flexible batteries in detail about their configurations, recent research advancements, and practical applications, including flexible lithium-ion batteries, flexible sodium-ion batteries, flexible zinc-ion batteries, flexible lithium/sodium-air batteries, and flexible zinc/magnesium-air batteries. Meanwhile, related comprehensive analysis is introduced to delve into the fundamental design principles pertaining to electrodes, electrolytes, current collectors, and integrated structures for various flexible batteries. [Display omitted] The rapid popularization of wearable electronics, soft robots and implanted medical devices has stimulated extensive research in flexible batteries, which are bendable, foldable, knittable, wearable, and/or stretchable. Benefiting from these distinct characteristics, flexible batteries can be seamlessly integrated into various wearable/implantable devices, such as smart home systems, flexible displays, and implantable sensors. In contrast to conventional lithium-ion batteries necessitating the incorporation of stringent current collectors and packaging layers that are typically rigid, flexible batteries require the flexibility of each component to accommodate diverse shapes or sizes. Accordingly, significant advancements have been achieved in the development of flexible electrodes, current collectors, electrolytes, and flexible structures to uphold superior electrochemical performance and exceptional flexibility. In this review, typical structures of flexible batteries are firstly introduced and classified into mono-dimensional, two-dimensional, and three-dimensional structures according to their configurations. Subsequently, five distinct types of flexible batteries, including flexible lithium-ion batteries, flexible sodium-ion batteries, flexible zinc-ion batteries, flexible lithium/sodium-air batteries, and flexible zinc/magnesium-air batteries, are discussed in detail according to their configurations, respectively. Meanwhile, related comprehensive analysis is introduced to delve into the fundamental design principles pertaining to electrodes, electrolytes, current collectors, and integrated structures for various flexible batteries. Finally, the developments and challenges of flexible batteries are summarized, offering viable guidelines to promote the practical applications in the future. [ABSTRACT FROM AUTHOR]

Solid state lithium-ion batteries (SSLIBs) with high safety and high energy density are promising novel energy storage devices. However, the performance of SSLIBs would descend under a wide work temperature range. A flexible ceramic-polymer composite solid electrolyte membrane was created by solution casting to obtain good stability of SSLIBs at different temperatures. The PVDF-HFP-PES-LiClO 4 -Li 6.4 La 3 Zr 1·4 Ta 0·6 O 12 (LLZTO) composite solid electrolyte shows excellent electrochemical performances in the temperature range of 20–60 °C. The ionic conductivity of PVDF-HFP-PES-LiClO 4 -LLZTO (PPLL) is 4.26 × 10−4, 4.97 × 10−4, 5.26 × 10−4, 5.59 × 10−4 and 5.97 × 10−4 S cm−1 at 20, 30, 40, 50 and 60 °C, respectively. The PPLL was employed in LiFePO 4 (LFP)/PPLL/Li batteries, and their properties were tested at 0.2 C. The test results show that the LFP/PPLL/Li battery has a good charge-discharge, rate, and cyclic performance at 20–60 °C. After 150 cycles with 0.2C at 30 °C and 60 °C, the capacity retention rates of 75.6 % and 86.4 %, respectively. This work provides an effective strategy for designing and preparing SSLIBs. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel embedded KVO 3 /NC anode is developed with 3 Li+ insertion/extraction mechanism. • A series of in-/ex-situ characterizations and DFT calculations clarify the reaction mechanism and structure–activity relationship. • KVO 3 /NC anode can deliver unparalleled electrochemical performances in both half- and full-cells. Vanadium-based metallic salts, characterized by their intrinsic low electronic conductivity, are impeding their advancement as anode materials in the realm of lithium-ion battery technology. This study presents a novel embedded anode material KVO 3 /NC (KVO/NC) synthesized via a sol–gel method, with KVO 3 (KVO) particles in situ growing on N-doped carbon, thereby ameliorating conductivity and electrochemical performance. The findings reveal that KVO/NC composite has three lithium-ion storage sites, ultra-high cycling stability (289 mA h/g@5000 cycles@10 C@100 %), and superior rate performance (249 mA h/g@15 C; 221 mA h/g@20 C). Coupled with LiFePO 4 cathode, it achieves a competitive energy density (391 W h kg−1@0.1 C; 1–3.9 V). This work reveals the practical potential of KVO/NC as a new type of lithium-ion battery anode material with high energy density and long cycle life through a series of ex situ/in situ characterizations. [ABSTRACT FROM AUTHOR]

The introduction of 0.6 TPFPB to the baseline can not only facilitate the electrochemical performance of Half-cell, but also enhance the stabilize the properties of Full cells, meanwhile resulting in the formation of superior B- and F-CEI layer. [Display omitted] • 1 TPFPB can enhance the cycling stability of the NCM811-Li half-cells or NCM811-graphite full-cells at high voltage. • Even at 60 ℃ and high voltage, the electrochemical stability of the TPFPB-containing NCM811-graphite full-cell had also been improved. • The CEI interfacial film of the cells containing TPFPB is more uniform and dense after cycling at 4.5 V. • The TPFPB molecules have the lowest LUMO values and higher HOMO values, which is able to prioritize redox reactions and participate in the formation of CEI films. • TPFPB has the lowest binding energy with Li+, which can reduce the de-solvation process of Li+, and have the highest binding energy with Co4+. Broadening the charging and discharging voltage window of high nickel cathode material NCM811 is the most expected method to improve the high specific energy density of batteries currently, yet the cathode-electrolyte interface (CEI) formed by the oxidized and decomposed products of carbonate-based electrolyte under high voltage are always so unsatisfied. Therefore, a voltage-stabilizer, TPFPB (Tris(pentafluoro)phenylborane), added into baseline electrolyte (1 M LiPF 6 in EC:EMC:DMC=1:1:1 vol%) to promote the electrochemical performance of the battery at 4.5 V. The results interpret that the TPFPB-contained NCM811-Li half-cells exhibit high specific capacity (167.10 mAh/g), excellent capacity retention rate (CRR) (75.37 %), and high rate performance (173.3 mAh/g at 5C) during 4.5 V. Meanwhile, through the analysis of the physical characterization techniques. the B- and F-rich interfacial layer, named as CEI film, existing at the interface between the cathode and the electrolyte, produced under 4.5 V, is superior, resulting in impeding the structural collapse of the cathode material and the continued dissolution of transition metal ions (TM n+) from the cathode material, as well as, ameliorate the electrochemical polarization of the battery, ultimately, it can stabilize the electrochemical performance of the battery under high voltage. Therein, the present work elucidate a new and substantial approach to enhance the high-voltage performances of rich-Ni cathode materials. [ABSTRACT FROM AUTHOR]

Benefiting from the synergistic effect of holey structures and carbon coating, the hG 0.01 @C 0.10 derived from waste graphite of used lithium-ion batteries displays excellent lithium storage properties. [Display omitted] • The NaOH was used for the separation and purification of waste graphite from used lithium-ion batteries and the creation of holey structures within waste graphite (hG). • The carbon coating by the annealing of phenolic resin enables hG 0.01 @C 0.10 with enhanced electrode kinetic and alleviated volume change during the cycles. • Benefiting from the synergistic effect of holey structures and carbon coating, the hG 0.01 @C 0.10 as anode for LIBs displays excellent lithium storage properties. The efficient recycling of waste graphite anode from used lithium-ion batteries (LIBs) has attracted considerable concerns mainly owing to the environment protection and reutilization of resources. Herein, we reported a rational and facile strategy for the synthesis of holey graphite coated by carbon (hG 0.01 @C 0.10) through the separation, purification and creation of holey structures of waste graphite by using NaOH and carbon-coating by using phenolic resin. The holey structures facilitate the hG 0.01 @C 0.10 with the quick penetration of electrolytes and rapid diffusion of Li+. The carbon coating is more favorable for hG 0.01 @C 0.10 with improved electronic conductivity and less alleviated volume during the cycles. Benefiting from the synergistic effect of holey structures and carbon coating, the hG 0.01 @C 0.10 as anode for LIBs displays a high reversible capacity of 377.6 mAh g-1 at 0.5 C and superior rate capabilities (e.g., 348.0 and 274.7 mAh g-1 at 1 and 2 C, respectively) and maintains a high reversible capacity of 278.7 mAh g-1 at 1 C after 300 cycles with an initial capacity retention of 80.0 %. [ABSTRACT FROM AUTHOR]

[Display omitted] Spinel Li 4 Ti 5 O 12 (LTO), a zero-strain material, is a promising anode material for solid-state thin-film lithium-ion batteries (TFB). However, the preparation of high-performance Li 4 Ti 5 O 12 thin-film electrodes through facile methods remains a significant challenge. Herein, we present a novel approach to prepare a binder- and conductor-free porous Li 4 Ti 5 O 12 (P-LTO) thin-film. This approach polyvinyl alcohol (PVA)-assisted spray deposition and does not require the use of complex or expensive methods. Adding PVA to the precursor solution effectively prevents thin-film cracking during high-temperature annealing, enhances adhesion, and forms a highly interconnected porous structure. This unique structure shortens the lithium-ion diffusion pathways and facilitates electron transport. Therefore, P-LTO thin film electrodes demonstrate exceptional rate capacity of 104.1 mAh/g at a current density of 100C. In addition, the electrodes exhibit ultra-long cycle stability, retaining 80.9 % capacity after 10,000 cycles at 10C. This work offers a novel approach for the preparation of high-performance thin-film electrodes for TFBs. [ABSTRACT FROM AUTHOR]

In recent years, perfluorinated hexanone has been widely used as a fire extinguishing agent for lithium-ion batteries in China. However, it can cause corrosion of ferrous materials in LIBs/batteries, such as storage tanks, battery boxes and ferrous connectors, while extinguishing LIBs fires. Therefore, when storing or using perfluorinated hexanone, it may cause secondary disasters. In order to clarify the corrosion mechanism and the structure of the products of perfluorinated hexanone on iron, we designed experiments to obtain "iron corrosion product". Then the main components of the corrosion products were studied by various chemical analysis methods and the corrosion mechanism was proposed. The results show that the main component of "iron corrosion product" is (CF3CF2COO)3Fe, which is generated by the reaction of CF3CF2COOH, the decomposition product of perfluorinated hexanone, with iron oxides. Accordingly, it can be determined that perfluorinated hexanone has certain safety hazards when used as a lithium-ion battery fire extinguishing agent. In order to avoid the above safety hazards of perfluorinated hexanone, it is recommended that when storing and using perfluorinated hexanone, it needs to be protected from light and moisture. [ABSTRACT FROM AUTHOR]

The enhancement of electrochemical performance in lithium‐ion batteries can be achieved through the incorporation of MoS2 with carbon materials and various metal sulfides. In this study, a ZnS/MoS2 heterostructure was developed, featuring a two‐dimensional nitrogen‐doped carbon nanosheet (NC) backbone. The synthesis of ZnMoZIF−L precursors was accomplished by introducing a Mo source in a 1 : 1 molar ratio during the ZIF−L synthesis process. Following high‐temperature carbonization and vulcanization treatment, ZnS/MoS2@NC composite materials were successfully synthesized. Compared to the unvulcanized ZnO/MoO3@NC and MoS2 samples, the ZnS/MoS2@NC composite exhibits remarkable lithium storage performance. At a current density of 500 mA g−1, the initial reversible capacity capacity is still as high as 1674 mAh g−1. Furthermore, this composite material demonstrates optimal rate capabilities and a significant contribution to pseudocapacitance. The nitrogen‐doped carbon framework effectively mitigates volume changes, while the heterostructural design provides more active sites for lithium‐ions, thereby enhancing lithium storage performance. [ABSTRACT FROM AUTHOR]

The silicon anode is one of the primary contenders for lithium‐ion batteries of higher energy density owing to its outstanding theoretical capacity. However, the native SiO₂ layer (2–5 nm) on commercial silicon nanoparticles severely limits ion transport and induces polarization, especially under high current densities. This study systematically examines the influence of SiO₂ layer thickness on silicon anode performance, identifying significant polarization as the main barrier to stable cycling. To tackle this, a strategic electrolyte additive is suggested, bis(trimethylsilyl)trifluoroacetamide (BTA), which mitigates these effects by scavenging inactive SiO₂ and promoting the formation of conductive LixSiOy intermediates. Experimental and computational results show that BTA dramatically reduces electrochemical polarization and enhances Li⁺ transport, leading to superior cyclic stability. The Si anode with BTA‐modified electrolyte maintains 1436.5 mAh g−1 after 120 cycles at 500 mA g−1—substantially outperforming the base electrolyte (894.5 mAh g−1). This work highlights a critical strategy for overcoming kinetic barriers and advancing silicon anodes toward practical, high‐density energy applications. [ABSTRACT FROM AUTHOR]

Surface coating lithium‐ion battery cathodes is a promising strategy to improve performance and mitigate cathode degradation. The coatings studied to date focus on either electronically or ionically conducting layers, which have been introduced to enhance the redox reactions of cathode particles, or oxide‐based physical protection layers limiting surface degradation. Such coatings require high‐temperature, time‐consuming synthesis processes, along with uncertainty in the specific interactions between these coatings and lithium ions. Here, metal‐phenolic network coated LiNi0.6Mn0.2Co0.2O2 (NMC) cathodes are, produced using naturally occurring polyphenols via a rapid one‐step assembly, improve cathode electrochemical performance. The performance improvement arises from the interaction between lithium ions and the coated layer, which enhances the lithium‐ion transport to the cathode. In half‐cell 1C rate cycling conditions, the modified cathode displays a 20% reduction in overpotential and a 54% decrease in interfacial resistance compared to the uncoated cathode. In a full‐cell format, the modified cathode exhibits a 10% increase in capacity and a 54% increase in lifespan for constant current cycling; in addition to a 5% increase in capacity and a 25% increase in lifespan for constant current‐constant voltage (CCCV) cycling. This work paves the way for improving cathode materials via eco‐friendly lithium‐ion attraction strategies. [ABSTRACT FROM AUTHOR]

A novel lithium salt (lithium di-fluoro di-nonafluoro-tert-butoxy borate) shows high solubility (>1 M) and flame-retardant properties in an electrolyte solution with conventional carbonate solvents as well as stable cycling in a high-voltage (4.8 V) LiNi0.5Mn1.5O4-graphite based lithium-ion battery. [ABSTRACT FROM AUTHOR]

Perovskite fluorides are attractive anode materials for lithium-ion batteries (LIBs) because of their three-dimensional diffusion channels and robust structures, which are advantageous for the rapid transmission of lithium ions. Unfortunately, the wide band gap results in poor electronic conductivity, which limits their further development and application. Herein, the cubic perovskite iron fluoride (KFeF3, KFF) nanocrystals (∼100 nm) are synthesized by a one-step solvothermal strategy. Thanks to the good electrical conductivity of carbon nanotubes (CNTs), the overall electrochemical performance of composite anode material (KFF-CNTs) has been significantly improved. In particular, the KFF-CNTs deliver a high specific capacity (363.8 mAh g−1), good rate performance (131.6 mAh g−1 at 3.2 A g−1), and superior cycle stability (500 cycles). Note that the surface conversion reactions play a dominant role in the electrochemical process of KFF-CNTs, together with the stable octahedral perovskite structure and nanoscale particle sizes achieving high ion diffusion coefficients. Furthermore, the specific lithium storage mechanism of KFF has been explored by the distribution of relaxation times technology. This work opens up a new way for developing cubic perovskite fluorides as high-capacity and robust anode materials for LIBs. [ABSTRACT FROM AUTHOR]

Owing to its higher earth element reserve and similar chemical properties to lithium, potassium ion batteries (PIBs) have been regarded as a potential alternative to lithium-ion batteries. And considering the relatively larger ionic radius of potassium, available electrode materials need to be equipped with enough space for volume expansion during charge–discharge cycles, thus graphitic carbon nanomaterials with adjustable layer spacing gradually come into researcher's version. Here with copper nanowires serving as growth template and organic polyvinyl pyrrolidone (PVP) providing carbon source, freestanding and ultra-light graphitic carbon nanotube (GCNT) aerogels were simply assembled and annealed, which were directly used as anodes of PIBs. Annealing parameters (temperature and atmosphere) were adapted to regulate the lattice order and interlayer spacing of GCNTs, and N, O heteroatoms derived from PVP were directly doped into the carbon lattice during thermal annealing, to optimize and enhance the cycle capacity and rate performance of GCNT anodes. The electrochemical potassium storage mechanism of GCNTs was also quantitatively analyzed. Most of the potassium ions are reversibly stored by squeezing into and escaping from the carbon lattice, and simultaneously oxygen-containing functional groups with different chemical states also offer active redox sites and dedicate partial capacity. Therefore, our assembled GCNTs with large lumen are expected to sandwich-like load with active substances efficiently, further constructing next-generation PIBs with excellent performance. [ABSTRACT FROM AUTHOR]

Silicon (Si) is considered to be one of the most promising anode materials for next‐generation lithium‐ion batteries because of its abundant reserves, low discharge potential, and most importantly, its high theoretical specific capacity. However, the practical application of Si‐based anodes is mainly hindered by the low intrinsic conductivity of Si and the large volume change upon lithiation/de‐lithiation. In order to improve the electrochemical performance of Si‐based anodes, we prepared a composite material consisting of Si nanoparticles (NPs) and coconut silk bio‐carbon (CSC) skeleton. The porous carbon skeleton derived from coconut silk with natural through‐holes and ample micropores on the wall, which was used as the carrier of Si NPs. The continuous through‐holes and well‐distributed oxygen‐containing functional groups of the CSC provided sufficient space and abundant adsorption active sites for Si NPs, what‘s more, the good dispersion of Si NPs in the through‐holes increased their contact with the surrounding carbon materials, which was conducive to electron transport. Meanwhile, the pore structure also provided buffer space for the volume expansion of Si. The rich oxygen‐containing functional groups can form a certain chemical force with silicon particles, and further stabilize the nano silicon particles. Hence, the CSC/Si electrode revealed an excellent capacity retention of 82.8 % at 1 A g−1 after 100 cycles. This study provides a simple universal high‐throughput method to obtain anode materials with outstanding electrochemical properties and promotes the further development of Si/C composites. [ABSTRACT FROM AUTHOR]

Mitigating the growth of dendritic lithium (Li) metal on silicon (Si) anodes has become a crucial task for the pursuit of long‐term cycling stability of high energy density Si‐based lithium‐ion batteries (LIBs) under fast charging or other specific conditions. While it is widely known that Li metal plating on Si‐based anodes may introduce inferior cycling stability and cause safety concerns, the evolution of the anode/material structure and electrochemical performance with Li metal plating remains largely unexplored. A comprehensive quantitative investigation of the hybrid Li storage mechanism, combining the Li alloying/dealloying mechanism and plating/stripping mechanism, has been conducted to explore the effect of Li plating on Si‐based anodes. The findings reveal that Li plating/stripping accounts for the decay of the overall Coulombic efficiency and cycling stability of the hybrid Li storage mechanism. Furthermore, alloying reactions occurring below 0 V encourage the formation of crystalline Li15Si4, which subsequently exacerbates voltage hysteresis. The performance decay is amplified as the ratio of Li plating/stripping capacity increases, or in other words, as the over‐lithiation level rises, thereby posing a threat to the battery's cycling stability. These results provide valuable insights into the design of advanced Si‐based electrodes for high energy density LIBs. [ABSTRACT FROM AUTHOR]

Lithium‐rich layered oxide cathodes (LLO) are renowned for their high specific capacity (>250 mAh g−¹) and have emerged as promising candidates for lithium‐ion batteries. However, significant capacity fades and voltage decay pose challenges to their commercialization, primarily due to the degradation of their original structure. In this study, a simple and rapid approach is presented that combines interfacial engineering and particle assembly to achieve a highly stable LLO cathode. This cathode features a single‐crystal LLO reassembled into a porous microsphere structure, along with a surface coating of polypropylene phosphate amide (PPA) formed through in situ cross‐linking of polyacrylic acid and ammonium polyphosphate, and a deuterogenic spinel interface layer. The dual protective coatings‐PPA and spinel‐effectively inhibit the dissolution of transition metals, delay structural deterioration, and enhance lithium‐ion diffusion. Additionally, the cross‐linked PPA layer strengthens the interconnection among LLO nanoparticles, improving the stability of the assembled microsphere structures while mitigating electrolyte corrosion. Consequently, the LLO@PPA electrode exhibits excellent capacity retention of 84.87% over 500 cycles at 0.5 C and shows significant improvements in rate performance. This work offers an effective modification strategy for developing next‐generation lithium‐rich cathodes with enhanced rate capacity and cycle life. [ABSTRACT FROM AUTHOR]

Amorphous FePO4 (AFP) is a promising cathode material for lithium‐ion and sodium‐ion batteries (LIBs & SIBs) due to its stability, high theoretical capacity, and cost‐effective processing. However, challenges such as low electronic conductivity and volumetric changes seriously hinder its practical application. To overcome these hurdles, core‐shell structure synthesis emerges as a useful solution. In this work, we for the first time made this comprehensive review on the progresses of core‐shell amorphous FePO4 (CS‐AFP). This review summarizes 1) various synthesis methods such as template method, microemulsion method, and other methods, 2) characterization techniques, and 3) their involvement in improving electrochemical performance in LIBs and SIBs. In terms of further understanding the underlying mechanisms of advancing electrochemical performance of CS‐AFP, the future perspective on two main aspects were insighted: (i) in situ characterization and (ii) novel designs of materials and structure for CS‐AFP. [ABSTRACT FROM AUTHOR]

Heat dissipation and collision safety are key factors affecting the safety of power battery systems. However, existing research on battery system safety only focuses on one aspect, with limited studies simultaneously addressing heat dissipation and collision safety. Therefore, this paper presents a gradient porosity aluminum foam battery module (GPAF-BM) with high heat dissipation efficiency and excellent crashworthiness by utilizing the enhanced heat transfer capability and good energy absorption characteristics of gradient open-cell aluminum foam (OCAF). To further improve its comprehensive performance, the heat dissipation efficiency and crashworthiness of the GPAF-BM are strictly optimized with multiple objectives. Additionally, to improve the efficiency of approximate model modeling, a new hybrid scaling multi-fidelity (NHSMF) approximate model construction method is proposed, which effectively improves the prediction accuracy of the model with a small sample size. Finally, the third-generation nondominant sorting genetic algorithm (NSGA-III) and normal boundary intersection (NBI) method are employed to ascertain the optimal solution. Compared to the original design, the optimized maximum intrusion displacement of the battery (Dmax) is 22.29% lower and the maximum battery temperature (Tmax) is reduced by 0.49 °C, the pressure drop of the (ΔP) decreased from the original design of 129.71 Pa to 115.53 Pa, a decrease of 10.93%. These improvements effectively enhance both the heat dissipation efficiency and crashworthiness of GPAF-BM. [ABSTRACT FROM AUTHOR]

The increasing demand for electric vehicles (EVs) has brought new challenges in managing battery thermal conditions, particularly under high-power operations. This paper provides a comprehensive review of battery thermal management systems (BTMSs) for lithium-ion batteries, focusing on conventional and advanced cooling strategies. The primary objective of this study is to assess and compare the effectiveness of various cooling approaches, including air-based, liquid-based, phase change material (PCM)-based, and hybrid systems. This review paper reveals that while traditional air- and liquid-based systems offer certain benefits such as simplicity and cooling efficiency, they are constrained by limitations in thermal conductivity and energy consumption. In contrast, PCM-based systems, despite their poor thermal conductivity, provide stable temperature regulation without requiring additional energy input. To overcome these limitations, the integration of thermal conductivity enhancers (TCEs) like carbon fibers, expanded graphite, and metal foams into PCMs significantly improves their performance. For instance, composite PCM (CPCM) enhanced with expanded graphite shows a marked improvement in thermal conductivity, increasing from 0.2 Wm−1 K−1 to 16.6 Wm−1 K−1, resulting in battery temperature reductions by up to 28%. Additionally, hybrid systems that combine active cooling with CPCMs, particularly when using nanoenhanced PCM with additives like graphene and metallic nanoparticles, demonstrate superior cooling efficiency, with temperature reductions of up to 50% compared to traditional systems. The uniqueness of this paper lies in its detailed comparison of the various BTMS strategies, including a thorough evaluation of hybrid systems that merge passive and active cooling techniques. We also explore the potential of nanoenhanced PCMs and hybrid CPCM systems, which offer significant advantages for high-power battery applications by providing both efficient heat dissipation and improved battery longevity. By synthesizing recent advancements in this field, this review highlights the most promising thermal management strategies, paving the way for future innovation in BTMS design for electric vehicles. [ABSTRACT FROM AUTHOR]

This study investigated the impact of precursor solution temperature on the electrodeposition of MnO2 material, which were prepared on a nickel substrate using the electrodeposition method under varying precursor solution temperatures of 25°C, 40°C, 50°C, and 60°C, respectively. These materials were subsequently employed as anodes in lithium-ion batteries to study their electrochemical performance. The results indicate that an increase in temperature induces preferential aggregation and growth of MnO2 nanosheets towards specific orientations, which is advantageous for enhancing the electrochemical performance of MnO2 electrode materials. Notably, the electrode material prepared at a solution temperature of 50°C exhibited optimal performance. Additionally, the charge transfer impedance was lower, which could be attributed to the growth of the highly conductive β-MnO2 main phase under 50°C. This study presents a novel approach for effectively improving electrodeposited nanomaterials, offering insights into the optimisation of electrochemical performance. [ABSTRACT FROM AUTHOR]

The conventional perspective suggests that low-concentration electrolytes (LCEs) face challenges in achieving stable charge/discharge properties due to the decreased ionic conductivity resulting from lower Liþ concentrations. However, the successful utilization of LCEs in lithium/sodium-ion batteries has brought them into the forefront of consideration for high performance battery systems. It is possible to achieve improved interface stability and ion transport performance for LCEs through adjusting electrolyte components, such as salts, solvents, and additives. This review provides timely update of the recent research progress, design strategies and remaining challenges of LCEs to answer several questions: i) What is the key factor for designing LCEs? ii) How to balance the low salt concentration and good ionic conductivity? iii) What is the interphasial mechanism of anode/cathode in LCEs? Firstly, the development of LCEs is discussed with typical examples. Subsequently, effectiveness of solvents on overall performances of LCEs is comprehensively summarized in detail. Finally, the challenges and possible research direction of LCEs are discussed. This review provides critical guidance for designing novel electrolytes for secondary batteries. [ABSTRACT FROM AUTHOR]

Lithium (Li) metal is a promising anode material for high energy density Li batteries due to its high specific capacity and low redox potential. However, its practical applications are hindered by issues such as Li dendrites, side reactions, and volumetric changes. Li-rich alloys have demonstrated potential in addressing these issues, as they can be easily synthesized and form an in situ three-dimensional scaffold embedded with metallic Li. This review comprehensively summarizes the properties of representative Li-rich alloys, including binary and multielement alloys. These alloys consist of both metallic and non-metallic elements, some of which can form solid solutions with Li, while others can form intermetallic compounds. The advantages and disadvantages of these alloys are compared and analyzed. Solid solution alloys are more stable than intermetallic compounds because there is no phase transformation within a certain range during the process of lithiation and delithiation. Li-rich alloys, such as Li-Mg, Li-Sn, and Li-Zn, exhibit promising merits, including high specific capacity, stable scaffold, high ionic conductivity, and low cost. This investigation provides a comprehensive perspective for the development of Li-rich alloy anodes towards practical application. [ABSTRACT FROM AUTHOR]

Key resources necessary for lithium-ion batteries (LIBs) will deplete rapidly if recycling is not considered given the significant demand for LIBs. However, the current recovery method from spent LIBs is hindered by low efficiency, high energy consumption, and severe environmental issues, which curtail the sustainability of recycling industry. Here, we propose a new strategy for selective elements extraction from LiCoO2 based on H2O-balance-regulated cation-anion competitive coordination. The lithium can be preferentially precipitated in deep eutectic solvents (DES) with an appropriate amount of H2O. Such a preferential lithium behaviors contributes to the subsequent precise separation of transition metal elements by further adjusting the water content, thus enabling the recovery of all element and direct regeneration of DES for further spent LIB recycling. The developed DES-based technology can achieve the ultrahigh leaching efficiency of 99.99% for Li and Co with an acceptable recovery efficiency of Li and Co (-91.23%) and a desirable purity of recycled Li2C2O4 and CoC2O4·2H2O (-98.43%). These Li and Co performances are still maintained at this level even after three-time regeneration of DES. This methodology can also be extended to other recycling chemistries of spent LIBs and lay the theoretical foundation for the recovery of valuable metals from spent battery materials using DESs with a simple process, low energy consumption, and waste-free recycling. [ABSTRACT FROM AUTHOR]

All‐solid‐state Li‐metal batteries (ASSLBs) are the most attractive next‐generation batteries due to intrinsic safety and high energy density. Particularly, composite solid electrolyte (CSE)‐based ASSLBs, highly compatible with conventional Li‐ion batteries, are nearing commercialization. However, the understanding of ASSLBs’ failure remains deficient, thereby considerably hindering their advancement. Herein, the unrecognized failing mode of ASSLBs, voltage noise failure (VNF), characterized by irregular charging voltage configuration, is identified using comprehensive techniques, including laser‐induced breakdown spectroscopy. The VNF originates from micro‐penetration of Li dendrites, which is demonstrated through direct observation of 3D Li concentration map in CSE. In this phenomenon, the transition metals, dissolved from the cathode, hop to the anode and serve as seeds for dendritic growth in VNF. Inspired by this mechanism and with the aid of DFT calculations, a transition metal scavenging layer is proposed using Prussian blue analogue at the cathode‐CSE interface. Consequently, ASSLBs with transition metal scavenging layer exhibit superior capacity (189 mAh g−1 at 0.5 C, NCM811) and stable cyclability (1200 cycles without failure). [ABSTRACT FROM AUTHOR]

Predicting the capacity and temperature of lithium-ion batteries is of critical significance to ensure their safety and stability, and consequently, extend the service life of battery systems. However, the degradation of capacity and thermal performance is typically regarded as independent processes, disregarding their coupling relationship. In response, this study constructs a combined model based on convolutional long short-term memory for the joint prediction of the reversible capacity and peak discharge temperature of batteries. The model's feature extraction and pattern reconstruction capabilities are well-acknowledged. A variety of charging and discharging features (e.g., current, voltage, temperature, and incremental capacity) are analyzed and correlated with the evolution trends of battery capacity and temperature during long-term operation. Moreover, the evident phenomenon of capacity regeneration caused by intermittent rest is considered. Finally, the prediction results for different cells from public datasets show that the root-mean-square errors of capacity prediction vary from 0.01179 to 0.03304, and the mean absolute percentage error of peak discharge temperature prediction can be basically kept lower than 0.6%. [ABSTRACT FROM AUTHOR]

Summary: Accurate estimation of lithium‐ion battery state of energy (SOE) is an important prerequisite for prolonging battery life and ensuring battery safety. To achieve a high‐precision estimation of the SOE, while a ternary lithium‐ion battery being the specifically targeted in this study, a novel method for SOE estimation is proposed, which combines limited‐memory recursive least squares (LM‐RLS) with strong tracking adaptive window Multi‐innovation cubature Kalman filtering (STW‐MCKF). In the LM‐RLS algorithm, the model parameters at the current time are updated with a limited dataset to solve the data saturation problem and improve the recognition accuracy of the RLS algorithm. The CKF algorithm is optimized by the STW algorithm in the STW‐CKF algorithm to enhance its robustness under strong disturbances. Additionally, a self‐adaptive window multiple innovation strategy is proposed to improve the accuracy of SOE estimation and the stability of the CKF algorithm, while maintaining a balance between computational complexity and SOE estimation accuracy. To validate the effectiveness of the algorithm, experiments are conducted under DST and BBDST conditions. The results show that the STW‐MCKF algorithm has a maximum convergence time of 4 s and an SOE estimation error within 1.04% under DST conditions. Under BBDST conditions, the maximum convergence time is 3 s, and the SOE estimation error is within 2.34%. Furthermore, the STW‐MCKF algorithm demonstrates good stability under the two conditions, indicating the effectiveness of the proposed method for lithium‐ion battery SOE estimation. [ABSTRACT FROM AUTHOR]

Aqueous rechargeable zinc ion batteries (ARZIBs) represent a cheaper and more environmentally friendly alternative to lithium-ion batteries (LIBs) in energy storage systems. Vanadium oxide is one of the most attractive materials to be used as a cathode in ARZIBs because it has multiple oxidation states that grant high specific capacity. This work employed an alternative synthetic route to obtain VO 2 with varied morphology and structural properties utilizing vanadyl acetylacetonate as a precursor by tuning the temperature during two-step solvothermal/hydrothermal treatment. When highly crystalline VO 2 (B) with rod morphology is obtained, the electrode exhibits the best electrochemical response, with the most significant contribution of surface-confined redox processes to the charge stored. The ARZIB assembled with VO 2 rod showed an initial capacity of up to ∼300 mA h g−1 (2.4 mA h cm−2) at 0.1 A g−1, delivering a specific energy of up to 168 W h kg−1 at a specific power of 65 W kg−1. It exhibits outstanding stability after 2000 GCD cycles at 2.5 A g−1. Ex-situ structural and spectroscopic characterization showed that Zn2+ storage causes an expansion and contraction of the lattice without evidence of crystalline phase transformations. [ABSTRACT FROM AUTHOR]

All-solid-state lithium-ion batteries are a promising next-generation technology because they have higher energy densities than their liquid-electrolyte counterparts. Halogen-rich argyrodite, specifically Li5.4(PS4)(S0.4Cl1.0Br0.6), was recently shown to have higher ionic conductivities compared with those of other argyrodite-like sulfides. Although the Li5.4(PS4)(S0.4Cl1.0Br0.6) in Li | Li5.4(PS4)(S0.4Cl1.0Br0.6) | Li(Ni0.8Co0.1Mn0.1)O2–Li5.4(PS4)(S0.4Cl1.0Br0.6) batteries have shown good electrochemical stability, the low discharge capacity limits the application of the battery. In continuation, this study examined the potential of a carbon additive for altering the electronic conductivity of the cathode and enhancing the capacity of Li | Li5.4(PS4)(S0.4Cl1.0Br0.6) | Li(Ni0.8Co0.1Mn0.1)O2–Li5.4(PS4)(S0.4Cl1.0Br0.6) batteries. After a 50-cycle charge/discharge, the carbon additive (0.1 C) enhanced the discharge capacity from 3.1 to 167 mAh/g, resulted in a capacity retention rate and coulombic efficiency of 95.4% and 99.9% when using 0.1 C and 0.5 C, respectively, and increased the resistance of the battery from 53 to 56 Ω. Therefore, the all-solid-state battery employing high-ion-conductive Li5.4(PS4)(S0.4Cl1.0Br0.6) and a carbon-modified cathode showed improved capacity. This study provides a proven framework for developing all-solid-state batteries employing halogen-rich argyrodite (Li7-α(PS4)(S2-αXα); α > 1) with enhanced ionic conductivities. [ABSTRACT FROM AUTHOR]

Electron tomography is an observation technique for nanometer-scale three-dimensional structures, using transmission electron microscopy (TEM). TEM tomography has been used to examine the 3D structures of various materials, such as biological samples and catalysts. In this study, we applied TEM tomography to battery materials. All-solid-state lithium-ion batteries have recently received much attention owing to their thermal safety. In all-solid-state cells, the electrode layer is composed of nonflammable solid electrolytes and electrode active materials. In order to improve the charge–discharge cycle performance, it is necessary that the electrolyte–electrode interface has no void spaces or defects. We used TEM tomography to investigate the solid interfaces of Sn–Li3PS4 (LPS) negative electrode composites of all-solid-state cells. We observed that Sn, Li-Sn alloy nanoparticles, and LPS glass electrolytes formed a solid interfacial contact with no void spaces during initial charge–discharge cycles. We suggest that as a new cycle deterioration analysis method, TEM tomography is useful in evaluating solid interfaces in all-solid-state cells. [ABSTRACT FROM AUTHOR]

Challenge of achieving high energy density (E) comparable with Li-ion batteries in supercapacitors, with low potential window offering aqueous electrolytes (1.2 V) has been overcome by using the electrode material composed of rGO 3.70%:PANI 51.86%:V2O5 33.33%:SnO2 11.11% (GPVS). The GPVS exhibited different extents of energy storage in the presence of 1 M sulphuric acid (H2SO4) and acidified supernatant liquid (ASL), a green electrolyte. Here, the ASL is the by-product, which is obtained as supernatant liquid after the synthesis of GPVS composites in an in situ synthetic method, and acidified using conc. H2SO4. The energy storage obtained in the presence of ASL is 38% higher than the energy storage obtained in the presence of H2SO4. The GPVS exhibited a remarkable feature of amelioration of energy storage with increase in CV cycles in the presence of H2SO4. The GPVS exhibited an extraordinary cyclic stability up to 41,300 cycles. The energy storage parameters achieved in the presence of H2SO4 after 33,800 cycles are, a specific capacitance (Cs) of 694.44 F g‒1, an E of 138.88 W h kg‒1 (comparable with E of Li-ion batteries) and a power density (P) of 2.1020 kW kg‒1 at 1 A g‒1. The energy storage parameters achieved in the presence of ASL are, a Cs of 212.31 F g‒1, an E of 42.46 W h kg‒1 (comparable with E of Ni–Cd batteries) and a P of 3.1583 kW kg‒1 at 2 A g‒1. It is satisfying that all these high energy characters are achieved with the real two electrodes–supercapacitor cell step up. The green supercapacitors are made by using the by-product, which is obtained as supernatant liquid after the synthesis of GPVS as its electrolytes. [ABSTRACT FROM AUTHOR]

In this work, Ni2+ was doped into the crystal lattice of LiFePO4 to improve the electrochemical performance. Lengths of the Li–O bonds in LiFe0.98Ni0.02PO4/C (2% NiSO4-doped LiFePO4) is longer than that of the bare LiFePO4 sample, the micromorphology of LiFe0.98Ni0.02PO4/C sample becomes uniform, and the Ni2+ doped into LiFePO4 expands the crystal plane spacing, which is conducive to Li+ diffusion. Amongst all the doped samples, the Li+ diffusion coefffcient of LiFe0.98Ni0.02PO4/C is the largest, and the redox peak of LiFe0.98Ni0.02PO4/C is more symmetrical, sharper and narrower, indicating that the proper amount of Ni2+-modified LiFePO4 can improve the electrochemical performance. Specific discharge capacity at 1C is 152 mAh g−1 when the doping amount is 2%. Additionally, after 200 cycles at 2C, the discharge specific capacity can be attained at 140 mAh g−1 and capacity retention rate reached 98%. [ABSTRACT FROM AUTHOR]

Silicon holds great potential as anode material for next-generation advanced lithium-ion batteries (LIBs) due to its exceptional capacity. However, its low conductivity and huge volume changes during charge/discharge process result in a poor electrochemical performance of silicon anode. This study introduces a cost-effective strategy to repurpose KL Si waste from photovoltaic industry into feedstock for LIBs. A Si@C composite with core–shell structure was synthesized from kerf loss (KL) Si waste as the primary capacity contributing ingredient. The nanoscale Si particles (Si NPs) was produced through ball milling and acid pickling of KL Si waste, and then coated a carbon shell by the pyrolyzed phenolic resin. This core–shell structure enhances the electrical conductivity of silicon-based anode, facilitates ion/electron movement, and reduces volume fluctuations of silicon during lithiation/de-lithiation process. Compared to the pure Si anode, the Li+ transmission efficiency of the Si@C anode was significantly improved, leading to a better cycle and rate performance. The resulting SP-2 electrode demonstrated a consistent capacity of 602 mAh g−1 after 150 cycles under current density of 0.5 A g−1. [ABSTRACT FROM AUTHOR]

This research introduces a novel perspective by concurrently modifying both surface and bulk through fluoride anion doping, enabling a comprehensive examination of the link between performance degradation and material depth. [Display omitted] • This work has clarified the distinction between the effects of surface and bulk fluoride anion doping on lithium-rich cathode materials. • This work indicates that higher F content on the surface of cathode particles is conducive to inhibiting oxygen release, reducing the propagation of oxygen defects from the surface to the bulk of particles, and reducing voltage decay. • This work shows that the uniform distribution of F elements is conducive to maintaining cyclic stability, and the sample has the smallest charge transfer impedance at large current density, showing good rate performance. • This work provides guidance for the adjustment of the modification depth and provides valuable insights for the design of Li-rich materials with long-term cyclic life and enhanced rate performance. Li-rich Mn-based (LMR) layered oxides are considered promising cathode materials for high energy–density Li-ion batteries. Nevertheless, challenges such as irreversible oxygen loss at the surface during the initial charge, alteration of the bulk structure, and poor rate performance impede their path to commercialisation. Most modification methods focus on specific layers, making the overall impact of modifications at various depths on the properties of materials unclear. This research presents an approach by using doping to adjust both surface and bulk properties; the materials with surface and bulk fluoride anion doping are synthesised to explore the connection between doping depth, structural and electrochemical stability. The surface-doped material significantly improves the initial Coulombic efficiency (ICE) from 77.85% to 85.12% and limits phase transitions, yet it does not enhance rate performance. Conversely, doping in bulk stands out by improving both rate performance and cyclic stability: it increases the specific discharge capacity by around 60 mAh g−1 and enhances capacity retention from 57.69% to 82.26% after 300 cycles at 5C. These results highlight a notable dependence of material properties on depth, providing essential insights into the mechanisms of surface and bulk modifications. [ABSTRACT FROM AUTHOR]

PMIA-BiOCl composite separators were prepared by means of non-solvent induced phase separation (NIPS). The positively charged oxygen vacancies in BiOCl nanosheets could interact with anions (PF 6 -) and anchor them on the PMIA fiber network, which realized the desolvation of Li+ for the purpose of ion-selection and improved the Li+ transport efficiency, leading to remarkably improved Li+ transference number (up to 0.79) and lithium-ion conductivity. Meanwhile, the sponge-like porous structure of PMIA-BiOCl composite separators and the efficient transport of Li+ alleviate the concentration polarization, regulate and uniformly deposit Li+, and reduce the growth of lithium dendrites. Therefore, compared with lithium-ion batteries (LIBs) assembled with commercial PP separators, the electrochemical and safety performance of LIBs assembled with PMIA-BiOCl composite separators are greatly improved. The rate capacity and cycle durability of LIBs assembled with PMIA-BiOCl composite separators can be significantly improved, which offers new prospects for high-performance LIBs. [Display omitted] Functional modification of inorganic particles is an effective approach to tackle the issue of Li+ transport and the lithium dendrites formation in lithium-ion batteries (LIBs). In this study, PMIA/BiOCl composite separators are prepared by nonsolvent induce phase separation (NIPS) method using P-type semiconductor bismuth oxychloride (BiOCl) functionalized poly (m-phenylene isophthalamide) (PMIA) separators. Compared with the polypropylene (PP) separator, PMIA has superior thermal stability and the addition of BiOCl further enhances its flame retardancy. And the prepared PMIA/BiOCl separator presents improved porosity (66.47 %), enhanced electrolyte uptake rate (863 %) and higher ionic conductivity (0.49 mS∙cm−1). Besides, the incorporation of BiOCl can anchor PF 6 - to the three-dimensional network skeleton of the PMIA/BiOCl separators, enabling the desolvation of Li+ and selectively facilitating Li+ transport (the Li+ transfer number is 0.79). Moreover, the uniform porous structure of the PMIA/BiOCl separators and the efficient transport of Li+ uniformly deposite Li+, and minimize the growth of lithium dendrites. Batteries assembled with PMIA/BiOCl separators have a discharge specific capacity of 124.4 mAh∙g−1 and capacity retention of 96.7 % after 200 cycles at 0.2C. Therefore, this work provides an effective route in the design strategy of separators for LIBs. [ABSTRACT FROM AUTHOR]

This article presents an experimental study that evaluated droop control strategies in DC microgrids with parallel-connected converters. In a decentralized control scheme, it is critical to ensure voltage regulation and load sharing in each converter to maintain a stable operation. Two scenarios are considered: the first involves two converters operating in parallel as voltage mode control, a conventional method discussed in the literature. In the second scenario, a less commonly used method is presented, in which one converter operates in voltage mode control and another operates in current mode control. The proposed decentralized control method is experimentally validated in a DC microgrid using parallel-connected lithium-ion batteries and converters. Load sharing results are examined under conditions with equal droop coefficients, demonstrating equivalent outcomes for specific load steps in both scenarios. However, in the case of different droop coefficients, the alternative method proves to be highly satisfactory, particularly for a broader range of load variations. The results confirm the efficacy of the control method in load sharing and voltage regulation among each converter, as well as the equivalence of control between both scenarios. [ABSTRACT FROM AUTHOR]

A simple and energy‐saving synthesis process for the high‐performance Si/C anode material of lithium‐ion batteries is advantageous for application. In this paper, the layered Si/C composite was synthesized by a low temperature one‐pot synthesis from industrial Ca−Si alloy and CCl4. The effect of synthesis temperature on the structure and performance of the products was investigated. We found that low temperature favors to the multilayer structure of Si/C. Taking the advantage of the layered structure, the Si/C‐300 anode material prepared at the temperature of 300 °C has good electrochemical performance of a reversible capacity of more than 1000 mAh g−1 at a current density of 2 A g−1 for 300 cycles, with a capacity retention ratio of 82.8 %, and an ICE of 77.0 %. At a high current density of 6 A g−1, the specific discharge capacity of 721.6 mAh g−1 can be achieved. The synthesis method provides a promising route to high performance silicon‐carbon anode materials. [ABSTRACT FROM AUTHOR]

Experimental determination of heat generation rates is crucial in the thermal safety design of automotive batteries. A thermal protection method (TPM) is proposed to determine the heat generation rates of 18650 cylindrical lithium-ion batteries under different discharge rates. The physical model based on the thermal protection method is established, and its feasibility is demonstrated through theoretical analysis. In the experimental setup, by introducing lateral thermal protection batteries (TPB) to minimize the heat loss of the center test battery (CTB), heat generation rates of the battery can be obtained based on the temperature change of the CTB. The average heat generation rates of the battery at 1, 2, and 3 C discharge rates are found to be 0.255, 0.844, and 1.811 W, respectively, which can be quadratically correlated with the discharge rate. In addition, a benchmark test of the present measurement against the commonly used accelerating rate calorimeter (ARC) was conducted. Relatively small deviations of 3.77%, 4.20%, and 1.09% were identified in the heat generation rates for the discharge rates at 1, 2, and 3 C. In comparison with the ARC equipment, the present TPM can be more representative of the transient battery heat generation characteristics with a much shorter time for thermal equalization. Finally, to further verify the accuracy of the present method, standard samples of the same size as the actual battery were made, which were capable of controlling heat generation through a direct current power supply. A comparison of the heat inputs of the standard sample with the heat generation rates measured by the thermal protection method shows a relative deviation of 1.01% maximum. With high measurement accuracy and an easy-to-build experimental setup, the proposed method has promising prospects in automotive applications. [ABSTRACT FROM AUTHOR]