Search

In recent years, recycling of numerous spent lithium-ion battery cathode materials has received increasing attention in order to protect the environment as well as to conserve resources, and the recovery of spent LiFePO4 (LFP) by direct regeneration has been widely studied. A considerable body of literature has delved into the failure mechanism of LFP. The mechanism is characterized by an irreversible phase change, which is primarily attributed to the sluggish diffusion of lithium ions (Li+) during cycling. Additionally, the migration of iron (Fe) ions to occupy Li+ sites further impedes Li+ diffusion. Consequently, the electrochemical performance of directly regenerated LFP is diminished by the phenomenon of Li defects. Here, a method of direct regeneration of LFP based on a doping strategy using environmentally friendly and economically efficient natural biomass amino acids has been developed, which inhibits Fe ion migration and improves the diffusion kinetics of Li+ and electrons by constructing a nitrogen-doped carbon coating. The regenerated LFP cathode exhibits excellent cycling stability and rate performance (98.7% capacity retention over 100 cycles at 1C current density and a high capacity retention of 87.9% after 500 cycles at 1C). [ABSTRACT FROM AUTHOR]

The Li5.5PS4.5Cl1.5 electrolyte gains significant attention due to its ultrahigh ionic conductivity and cost-effectiveness in halogen-rich lithium argyrodite solid electrolytes. The conventional synthetic method for obtaining the electrolyte involves mechanical milling followed by post-annealing. However, these synthesis methods typically involve high milling speeds, elevated temperatures, and prolonged durations, resulting in both high energy consumption and potential damage to the electrolyte. In this study, we successfully obtained Li5.5PS4.5Cl1.5 with a high conductivity of 7.92 mS cm−1 using a milling speed of 400 rpm and annealing at 400 °C for 5 hours. When incorporated into a Li4Ti5O12-based all-solid-state battery, this electrolyte demonstrates stable cycling performance across varying temperatures. [ABSTRACT FROM AUTHOR]

Sulfurized polyacrylonitrile (SPAN), featuring uniform dispersion of short-chain sulfur in an organic skeleton, shows great promise in lithium–sulfur (Li–S) batteries due to the inhibited polysulfide dissolution and hence improved electrochemical performance. However, the practical applicability of SPAN is significantly limited by its relatively poor ionic and electronic conductivity, as well as sulfur content (<50%). Herein, triallyl isocyanurate (TI) is incorporated to fabricate SPAN fibers with robust chemical structure and high sulfur loading. The fine-tuned organosulfur cathode (Se0.05S0.95PAN-TI11, 1F) demonstrates increased S&Se content of 54.2% and excellent electrochemical performance in Li/Na–S batteries. As a result, 1F exhibits an ultrahigh composite capacity of 671 mA h g−1 at 0.1C (capacity retention up to 100%) and remarkable rate capability of 405 mA h g−1 at 8C in Li–S batteries. Additionally, 1F shows prolonged cycling ability over 300 cycles at 0.5C when applied in an RT-S battery. Notably, under harsh conditions (S&Se loading of 5.5 mg cm−2 and E/S&Se = 5 μL mg−1), the Li–1F battery displays a brilliant initial areal capacity of 8.0 mA h cm−2 at 0.1C (reversible capacity of 6.3 mA h cm−2) and retains a capacity of 5.3 mA h cm−2 at the 200th cycle (capacity retention of 84%). Consequently, 1F is promising for practical applications in high-performance metal–S batteries. [ABSTRACT FROM AUTHOR]

Inorganic sulfide solid electrolytes with high ionic conductivity and low interfacial resistance attract extensive research attention. Here, we successfully synthesize Li6.7P0.3Ge0.7S5I argyrodite electrolyte with ultrahigh Li-ion conductivity (13.1 mS cm−1 at room temperature) and low activation energy (0.19 eV). All-solid-state lithium batteries based on the prepared electrolyte and pristine LiNi0.8Co0.1Mn0.1O2 cathode show fast capacity degradation due to the side reaction between the active materials and Li6.7P0.3Ge0.7S5I electrolytes. XRD and TEM results confirm the existence of MnO2 and Ni3S2 at the interface between the pristine cathode and solid electrolyte, leading to high resistance and poor electrochemical performances. SEM results indicate that the large volume changes during cycling also contribute to the deteriorating battery performance. A thin layer of the Li2ZrO3 coating layer is then applied onto the surface of cathode materials, which delivers superior capacity properties and cyclability at ambient temperature. The coated electrode also delivers a high area capacity of 5.1 mA h cm−2 with an ultrahigh area loading of 26.8 mg cm−2 at 0.5C at ambient temperature when combined with the Li6.7P0.3Ge0.7S5I electrolytes. Moreover, the assembled battery offers an initial discharge capacity of 107.8 mA h g−1 at 0.1C at −20 °C and maintains a capacity retention of 62% after 200 cycles. [ABSTRACT FROM AUTHOR]

Polymer electrolytes (PEs) are promising for constructing solid-state batteries with high energy density due to the great flexibility and high processability. However, it is difficult to construct such a system which is able to overcome the poor electrode/electrolyte interface contact, the growth of lithium dendrites and severe decomposition against a high-voltage cathode. Herein, a "polymer-in-salt" electrolyte (PISE) is in situ prepared to promote lithium ion transport, stabilize the lithium anode and improve the compatibility between PEs and the high-voltage cathode. With the high content of lithium salt (54 wt%) in the PISE, the lithium ion transference number is 0.6 at room temperature, and the Li/PISE/Li symmetric cells show a stable polarization voltage over 1000 h. What's more, the assembled NCM622/PISE/Li batteries display impressive high-voltage cyclability with 92.5% capacity retention over 160 cycles. Additionally, the NCM811/PISE/Li batteries also exhibit remarkable cycling stability at room temperature. This work provides the possibility of designing high-voltage solid-state lithium metal batteries by in situ polymerization. [ABSTRACT FROM AUTHOR]

Lithium–sulfur (Li–S) batteries have become the most promising candidates for next-generation power storage technologies owing to their ultrahigh energy density and low cost. However, practical Li–S batteries, operated under harsh conditions with high sulfur loading, low electrolyte-to-sulfur (E/S) ratio and low negative-to-positive capacity ratio (N/P), are significantly impeded by several inherent drawbacks, including the shuttle effect of polysulfide intermediates, short lifespan, and sluggish reaction kinetics. Herein, we systematically summarize and analyze the cyclability of Li–S batteries with an areal capacity over 5 mA h cm−2, and particularly pay great attention to the key parameters of high-sulfur-loading cathodes tested under low E/S ratio (E/S ≤5 μL mg−1) and N/P ratio (N/P ≤5) circumstances to point out key strategies for the optimization of electrochemical performance. We clarify the development roadmap, analyze related scientific challenges, standardize the electrochemical test conditions of practical sulfur cathodes and uncover the cyclability limits to promote the industrialized process of lithium–sulfur batteries. We systematically summarize the current Li–S pouch batteries with considerable performance under practical conditions and also emphasize the failure mechanism analysis. Consequently, this review not only provides various thresholds of electrochemical properties in both coin cells and pouch cells but also offers feasible devices to facilitate practical and commercial applications of lithium–sulfur batteries in the near future. [ABSTRACT FROM AUTHOR]

All-solid-state sodium batteries (ASSSBs) are promising to be applied to large-scale energy storage systems due to the extensive source of raw materials, high safety, and high energy density. As one of the key materials for ASSSBs, sodium solid electrolytes (SSEs) have attracted significant attention in recent years. Therein, chalcogenide-based inorganic sodium solid electrolytes (ISSEs) stand out owing to their decent room temperature ionic conductivity and lower mechanical stiffness. The fundamental understanding of the structure–activity relationship is of great significance for guiding the design of chalcogenide-based ISSEs. In this review, we provide an overview of the research progress in chalcogenide-based ISSEs based on their crystal structures, synthetic methods, chemical/electrochemical properties, and structure–activity relationship, especially focusing on the perspective of crystal structure designs. We hope to provide some prospects and thoughts for the design of relevant solid electrolytes (SEs) in the future. [ABSTRACT FROM AUTHOR]

Using a solid-state conversion in a liquid electrolyte, lithium–sulfur batteries maintain an advantage of having no polysulfide dissolution; however, they suffer from intrinsically sluggish reaction kinetics. Herein, tellurium is employed as a eutectic accelerator to enhance the reactivity of lithium–sulfur batteries under solid-state conversion. An SEI (solid electrolyte interface) is formed in situ on a CMK-3/S8 cathode, which enables reactants to undergo solid-state conversion in an ether electrolyte. Electrochemical studies reveal that Te doping can accelerate the diffusion of lithium ions and reduce the reaction resistance, which are beneficial for the reaction kinetics. X-ray photoelectron spectroscopy and electrochemical impedance spectroscopy analyses indicate that Te doping produces an SEI film with high lithium ion conductivity and low impedance. The CMK-3/S-Te-1 cathode, with 1 wt% Te doping, delivers a high reversible specific capacity of 1150.2 mA h g−1 at 0.1C and 726.9 mA h g−1 at 0.2C over 200 cycles. This work furnishes a strategy of using Te as a eutectic accelerator to enhance reactivity for lithium–sulfur batteries under a solid-state conversion and presents a promising avenue for application in lithium–sulfur batteries. [ABSTRACT FROM AUTHOR]

Polydiaminoanthraquinones, featured as redox-active quinone segments linked by polyaniline, were investigated as novel organic cathodes for K-ion batteries. With electron-withdrawing groups (CN) substituted, elevations of the redox potential and capacity utilization were achieved. [ABSTRACT FROM AUTHOR]

Hard carbon is one of the most promising anode materials for sodium ion batteries (SIBs) due to its low cost, high conductivity and suitable potential; however, its application is hindered by its relatively low capacity, and unsatisfactory rate capability and cyclability. Herein, we have reported a high performance SIB anode of S-doped interconnected carbon nanofibers (denoted as S-CNFs) that was directly derived from the industrial waste product bacterial cellulose, demonstrating great potential for practical application and sustainable development. The S-CNFs present high reversible capacities of 460 mA h g−1 at 0.05 A g−1 and 255 mA h g−1 at 10 A g−1, and preserved a capacity of 310 mA h g−1 at 1 A g−1 after 1100 cycles. Structural and electrochemical analyses revealed that multiple factors including the expanded (002) interlayer spacing, the electrochemically active –C–S–C– covalent bonds, the capacitive process induced by a large surface area and considerable defects as well as the stable structure associated with the cross-linked network contributed to their excellent performance. Furthermore, the first principles evaluations confirmed the sodium-storage mechanism of sulfur doping, which not only improved the interlayer distance for the mobility of Na+ but also promoted the electronegativity as well as the electrochemical activity and increased the adsorption of Na+. [ABSTRACT FROM AUTHOR]

Pyrite (FeS2) is considered an attractive Na-storage anode owing to its abundance, environment friendliness and high theoretical capacity (894 mA h g−1). However, it still remains great challenges to realize an applicable FeS2 electrode with both high reversible capacity and long cycle life. In this study, micron-sized FeS2@C composed of FeS2 nanoparticles uniformly embedded in carbon matrix was investigated as a conversion-type anode for sodium ion batteries by coupling with various electrolytes. It is demonstrated that the electrolyte formulations, i.e., both solvents and Na salts, play vital roles in the Na storage performance of FeS2. The combination of NaPF6 and DME was highly advantageous for constructing robust SEI films with high Na+ conductivity, guaranteeing fast and reversible conversion reactions in the wide electrochemical window of 0.005–3 V (vs. Na/Na+). Owing to the fast charge transfer kinetics and high chemical compatibility between the electrolyte and electrode, the as-prepared FeS2@C could deliver a high reversible capacity of 853 mA h g−1 at 0.2 A g−1 and 459 mA h g−1 at 40 A g−1, a remarkable initial coulombic efficiency of 84.7% and excellent cycling stability with capacity retention of 83.2% over 1000 cycles. These parameters prove the great potential of FeS2@C in fulfiling commercial demands for wide range of energy storage applications. [ABSTRACT FROM AUTHOR]

The permeation of dissolved lithium polysulfides across the porous polyolefin-based commercial separator is a major hindrance for using lithium sulfur batteries (LSBs). In this work, the poly(vinylidene fluoride) (PVDF)-based gel polymer electrolyte (GPE) with a compact morphology to block polysulfide penetration is prepared using a simple solution-casting method, and the strategy of incorporating poly(ethylene oxide) and nano zirconium dioxide is applied to guarantee electrolyte uptake and Li+ mobility. Superior to the commercial separator with liquid electrolyte, the LSB assembled with additive-free GPE exhibits a high initial capacity of 1429 mA h g−1, coulombic efficiency of 96% at 0.2C and improved rate performance. After 500 cycles at 1C, the LSB could still deliver a capacity of 847.2 mA h g−1, with a low fading rate of 0.05%. The LSB with high sulfur loading (5.2 mg cm−2) could attain a high areal capacity of 4.6 mA h cm−2. Results of scanning electron microscopy suggest that such a hybrid GPE could effectively protect the lithium anode from polysulfide corrosion. Therefore, this novel membrane of hybrid PVDF-based GPE provides a simple and effective method to establish high-performance LSBs. [ABSTRACT FROM AUTHOR]

A type of Na3V2(PO4)3/C (NVP/C) cathode material for sodium ion batteries was synthesized via a facile solid-phase method. Agarose, a natural polysaccharide from seaweed that can form a 3D network structure through hydrogen bonds in polar solvents, was used as a carbon source and a medium to form NVP/C particles as nanograins with a thin layer of carbon coating in a 3D carbon network. As the cathode, the NVP/C material exhibited a reversible capacity of 116 mA h g−1 at 1C, which is very close to its theoretical capacity (117.6 mA h g−1), with a capacity retention of 97.3% after 500 cycles. At 20C, the NVP/C had a capacity of 100 mA h g−1 and still kept a relatively stable capacity of 78 mA h g−1 after being cycled 7000 times. Based on the excellent performance of the obtained cathode material, a sodium ion full cell was assembled with S-doped carbon as the anode, which delivered 110 mA h g−1 of discharge capacity at 200 mA h g−1 (calculated using NVP as the cathode) and displayed an average voltage of around 1.7 V. All of these results imply that the prepared NVP/C has potential for application in sodium ion batteries for large-scale energy storage. [ABSTRACT FROM AUTHOR]

NiSx–rGOS is prepared via a facile and cost effective hydrothermal process, with the structure of ultrafine NiSx nanospheres uniformly wrapped in the in situ S-doped rGO matrix. The uniform nanostructural NiSx and high conductivity of S-doped rGO (rGOS) can effectively increase the ionic and electronic conductivity of the NiSx–rGOS composite, thus resulting in high capacity utilization of the active materials. Moreover, the buffering layer provided by the rGOS matrix can accommodate the volume change of the NiSx and protect the nanoparticles from aggregation during the repeated cycling process. The as-prepared NiSx–rGOS composite demonstrates a high reversible capacity of 516 mA h g−1 at 0.2 A g−1 with a capacity retention of 96.8% over 100 cycles and a remarkable rate performance of 414 mA h g−1 at 4 A g−1, possibly exhibiting the best electrochemical performances of nickel sulfide for sodium-ion batteries. [ABSTRACT FROM AUTHOR]

It has been documented that W-modified Pt catalysts with relatively high tungsten contents are effective for the catalytic transformation of biodiesel-derived glycerol to 1,3-propanediol (1,3-PDO). Herein, we report a new finding that Pt/W–SBA-15 catalysts with extremely low W/Si atomic ratios (≤1/80) exhibit excellent catalytic performance in the hydrogenolysis of glycerol to 1,3-PDO. In particular, a Pt/W–SBA-15 catalyst with the W/Si ratio of as low as 1/640 (Pt/W–SBA-15(1/640)) gave rise to the highest 1,3-PDO selectivity of 70.8% at a high glycerol conversion of 86.8% and thus afforded the highest yield of 1,3-PDO of 61.5%. A combination of characterization techniques evidenced that tungsten was homogeneously incorporated into SBA-15 in the form of isolated tetragonal WO4 and only displayed Lewis acidity. The particle size of Pt evolved in a reverse volcanic curve with the W/Si ratio, with the smallest size being observed for Pt/W–SBA-15(1/640). Control experiments indicated strong synergy between Pt nanoparticles (NPs) and WO4 in the hydrogenolysis of glycerol. A probe reaction suggested that Brønsted acid sites were generated in situ on the Pt/W–SBA-15 catalysts in a H2 atmosphere by the reaction between WO4 and spillover H atoms from the Pt NPs. It is plausible that the hydrided WO4 functioned as a highly selective active centre in the hydrogenolysis of glycerol to 1,3-PDO, whereas the Pt NPs played the role of a reservoir of spillover H atoms. Thus, a good match between the isolated WO4 and the small Pt NPs was responsible for the superior catalytic performance of Pt/W–SBA-15(1/640). [ABSTRACT FROM AUTHOR]

Metallic Sb has been extensively researched as a Na storage anode due to its high capacity and low cost, but it suffers from poor cycling stability stemming from its huge volume change (∼390%) during cycling. Herein, a unique two-dimensional hybrid structure of SbOx nanoplates encapsulated by carbon flakes (SbOx@CF) was fabricated by templating with soluble NaCl. Benefiting from its two-dimensional structure providing rapid Na+ ion uptake and removal and uniform coating endowing a stable buffer layer, the hybrid presents a high reversible capacity (451 mA h g−1) and excellent rate capability (114 mA h g−1 at 4 A g−1), as well as stable cycling (442 mA h g−1 after 100 cycles with 98% capacity retention). This work opens up a facile, controllable, economical and extendable approach to prepare advanced two-dimensional metal oxides for batteries and supercapacitors. [ABSTRACT FROM AUTHOR]

Sodium ion batteries are attractive alternatives to lithium ion batteries for stationary energy storage technology, and titanates are considered as promising anode materials for sodium ion batteries. Herein, a series of sodium titanates were synthesized via a simple, fast and controllable electrochemical route from solid TiO2 in molten salts of NaF–NaCl–NaI. For the first time, the as-prepared Na0.23TiO2 and Na0.46TiO2 were utilized as anode materials for sodium ion batteries, with a sodium storage capacity of 185 mA h g−1 and 215 mA h g−1 after 200 cycles, respectively. High rate and long term tests indicated the excellent cycle performance due to the formation of a 3D porous electrode structure during the long term charge/discharge processes. [ABSTRACT FROM AUTHOR]

A Na-rich cathode is developed by grafting the electron-withdrawing –SO3Na group on polyaniline chains. Due to the immobile doping and effective activation of the sulfonate group, this polymer demonstrates a high capacity (133 mA h g−1) and excellent cyclability through a cation-exchange reaction, offering a low cost and sustainable cathode for SIBs. [ABSTRACT FROM AUTHOR]

The Li 5.5 PS 4.5 Cl 1.5 electrolyte gains significant attention due to its ultrahigh ionic conductivity and cost-effectiveness in halogen-rich lithium argyrodite solid electrolytes. The conventional synthetic method for obtaining the electrolyte involves mechanical milling followed by post-annealing. However, these synthesis methods typically involve high milling speeds, elevated temperatures, and prolonged durations, resulting in both high energy consumption and potential damage to the electrolyte. In this study, we successfully obtained Li 5.5 PS 4.5 Cl 1.5 with a high conductivity of 7.92 mS cm -1 using a milling speed of 400 rpm and annealing at 400 °C for 5 hours. When incorporated into a Li 4 Ti 5 O 12 -based all-solid-state battery, this electrolyte demonstrates stable cycling performance across varying temperatures.

An organoselenide compound, phenyl diselenide (PDSe), is employed as a soluble electrolyte additive to enhance the kinetics of a sulfurized polyacrylonitrile cathode, in which radical exchange in the solid-liquid interface forms dynamic S-Se bonds. Consequently, the PDSe assisted cathode exhibits enhanced battery performance in both ether and carbonate electrolytes.