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Prediction of state of health (SOH), a crucial aspect of battery management systems, necessitates accurate and reliable estimations for lithium-ion batteries. However, achieving high-precision SOH estimation using the deep extreme learning machine (DELM) in complex environments is challenging due to the instability caused by its random key parameters. To address this, we propose a novel approach that combines the improved bald eagle search (IBES) algorithm with DELM. By utilizing the IBES algorithm, we can extract highly relevant health indicators from the battery's parameter curve during charging and discharging, as well as the incremental capacity curve. These indicators serve as inputs to the constructed estimation model, which predicts SOH under different working conditions. The proposed method has been validated using publicly available experimental data, with an overall error in SOH estimation of less than 1%. In comparison to the existing model, the proposed method achieves RMSE, MAE, and MAPE values lower than 0.35%, 0.26%, and 0.21%, respectively. These findings demonstrate that the proposed method excels in terms of both the speed and accuracy of SOH estimation, showcasing its enhanced robustness and reliability. [ABSTRACT FROM AUTHOR]

The advancement of lithium-ion battery technology relies on the development of materials that not only improve performance but also align with environmental sustainability. This work presents a novel water-based pectin-PEG binder for LiFePO 4 cathodes that combines eco-friendliness with electrochemical innovation. The binder material is made by mixing pectin, a flexible natural substance, with polyethylene glycol through a radical copolymerization process. This combination gives the binder both flexibility and a boost in electrical performance. Our experimental results demonstrate that LFP cathodes with this binder have an intriguing self-healing ability in comparison with the conventional PVDF binder, enhanced charge-discharge capacities, improved cycling stability, and higher ionic conductivity. Specifically, electrodes utilizing the pectin-PEG binder exhibit an impressive retention of discharge capacity. They maintain roughly 150 mAh g−1 after 500 cycles at 1C with 99% retention, and about 141 mAh g−1 with 97% retention at 3C. Cyclic voltammetry (CV) confirms that the PP binder maintains its ionic diffusion properties at high sweep rates, whereas galvanostatic intermittent titration technique reveals a much higher lithium ion diffusion coefficient (D Li+) within the operational voltage range of the LFP-PP250 electrodes. These findings establish an attractive direction for the development of electrodes for high-energy density, sustainable lithium-ion batteries. [Display omitted] • The pectin-PEG binders offer eco-friendliness and innovation for LiFePO 4 cathodes. • The pectin-PEG binder exhibits self-healing properties, enhancing battery life. • CV and GITT analyses show enhanced lithium ion diffusivity. • The pectin-PEG binder improves the battery performance of the LFP cathodes. • Electrodes maintain ∼150mAh g−1 after 500 cycles at 1C and ∼141mAh g−1 at 3C. [ABSTRACT FROM AUTHOR]

Large volume changes of lithium-ion batteries during battery operation affect battery lifetime and performance through mechanical degradation. Therefore, understanding the coupling between mechanics and electrochemistry in these systems is crucial. In this work, we use neutron diffraction to learn how commercial lithium-ion pouch cells are affected by stack pressure during charge and discharge. We find that a change in stack pressure affects the phase transitions in electrode materials, requiring more charge to reach higher state-of-charge phases which results in effective capacity loss for the battery. Also noteworthy is that the copper current collector experiences strain during charge and discharge due to the expansion of the graphite anode, something often overlooked in these systems. • Neutron diffraction reveals how stack pressure affects charging lithium-ion cells. • Lithium-ion pouch cells lose capacity when charged under applied stress. • Copper current collector experiences significant strain during charge cycling. • Electrode phase transitions require more charge under higher stack pressures. [ABSTRACT FROM AUTHOR]

The gradient-structure is ideal nanostructure for conversion-type anodes with drastic volume change. Here, we demonstrate an inorganic-organic competitive coating strategy for constructing gradient-structured ferroferric oxide-carbon nanospheres, in which the deposition of ferroferric oxide nanoparticles and polymerization of carbonaceous species are competitive and well controlled by the reaction thermodynamics. The synthesized gradient-structure with a uniform size of ~420 nm consists of the ferroferric oxide nanoparticles (4–8 nm) in carbon matrix, which are aggregated into the inner layer (~15 nm) with high-to-low component distribution from inside to out, and an amorphous carbon layer (~20 nm). As an anode material, the volume change of the gradient-structured ferroferric oxide-carbon nanospheres can be limited to ~22% with ~7% radial expansion, thus resulting in stable reversible specific capacities of ~750 mAh g−1 after ultra-long cycling of 10,000 cycles under ultra-fast rate of 10 A g−1. This unique inorganic-organic competitive coating strategy bring inspiration for nanostructure design of functional materials in energy storage. The gradient-structure is ideal nanostructure for conversion-type anodes with drastic volume change. Here, the authors demonstrate an inorganic-organic competitive coating strategy to construct gradient-structured Fe3O4@C nanospheres. [ABSTRACT FROM AUTHOR]

The use of inexpensive graphite oxide (GO) as a carbon source, instead of the expensive reduced graphene oxide (rGO), is essential to prepare metal oxide/rGO composites. In this work, we investigated the in situ reaction of GO and FeCl3 to produce Fe2O3/rGO composites as anode materials for high‐energy lithium‐ion batteries (LIBs). In this reaction, iron ions combined with the oxygen‐containing functional groups of GO, which subsequently grew into Fe2O3 nanoparticles, whereas the GO transformed into rGO under hydrothermal conditions. In the composite Fe2O3−rGOx samples, intergranular gaps in the Fe2O3 sub‐micron particles evidently increased the contact between the Fe2O3 active material and the electrolyte, which improved the Li‐ion conductivity and electrochemical performance of the Fe2O3−rGOx composites. The Fe2O3−rGO2 sample showed the best cyclic performance and delivered the highest capacity of all samples. The initial discharge and charge capacities of Fe2O3−rGO2 were 1086.3 and 722.4 mAh g−1, respectively. After 100 cycles, the discharge specific capacity of Fe2O3−rGO2 was 653.2 mAh g−1 and the coulombic efficiency was 98.4 %. We found that an appropriate weight ratio and composite morphology of Fe2O3−rGOx were important in influencing the electrochemical properties of the composite anode materials for high‐energy LIBs. [ABSTRACT FROM AUTHOR]

Succinonitrile (SN) has been used as functional additive to improve the thermal stability and broaden the oxidation electrochemical window of commercial electrolyte 1 M LiPF 6 /EC/DEC (1:1, by volume) for high-voltage LIBs (cathode: Li 1.2 Ni 0.2 Mn 0.6 O 2 , anode: Li). 1 wt % SN-based electrolyte showed a wide electrochemical oxidation window of 5.4 V vs Li + /Li and excellent thermal stability demonstrated by thermogravimetry (TG) and X-ray photoelectron spectroscopy (XPS), as well as theoretical analysis according to molecular orbital theory. The LNMO (Li 1.2 Ni 0.2 Mn 0.6 O 2 ) battery with 1 wt % SN-based electrolyte showed better cyclability and capacity retention when charged to higher cut-off voltage. The improved battery performance is mainly attributed to the formation of uniform cathode electrolyte interface (CEI) formed by interfacial reactions between the LNMO cathode and electrolyte. The outcome of this work and the continuous research on this subject can generate critical knowledge for designing thermal stability electrolytes for large format lithium-ion batteries. [ABSTRACT FROM AUTHOR]

The aqueous redox flow battery (ARFB), a promising large-scale energy storage technology, has been widely researched and developed in both academic and industry over the past decades owing to its intrinsic safety and modular designability. However, compared to other technologies (e.g. Li-ion batteries), the relatively low energy density, inferior efficiency, and high investment cost of the ARFB limit its further applications. Although tremendous efforts have been made to improve the performance as well as the cost-effectiveness of ARFB by various approaches, it is still a challenge to recognize a united and general roadmap for the next commercial-available ARFB. Here we review the evaluation criteria for the performance of flow batteries and the development status of different types of flow batteries. The factors affecting the performance of flow batteries are analyzed and discussed, along with the feasible means of improvement and the cost of different types of flow batteries, which is expected to provide useful references for the further development of high-efficiency and low-cost flow batteries. • Performance/cost balance is the key to low cost flow batteries • The characteristics of various aqueous redox flow batteries are discussed • Challenges include low energy density, slow kinetics, and instability • Future trends favor aqueous organic and iron-based chemistries [ABSTRACT FROM AUTHOR]

Abstract: As hybrid and electric vehicle technologies continue to advance, car manufacturers have begun to employ lithium ion batteries as the electrical energy storage device of choice for use in existing and future vehicles. However, to ensure batteries are reliable, efficient, and capable of delivering power and energy when required, an accurate determination of battery performance, health, and life prediction is necessary. This paper provides a review of battery prognostics and health management (PHM) techniques, with a focus on major unmet needs in this area for battery manufacturers, car designers, and electric vehicle drivers. A number of approaches are presented that have been developed to monitor battery health status and performance, as well as the evolution of prognostics modeling methods. The goal of this review is to render feasible and cost effective solutions for dealing with battery life issues under dynamic operating conditions. [Copyright &y& Elsevier]

In this work, hierarchical hexagonal nanoplates NiO composite with microcrystalline graphite are successfully synthesized by a hydrothermal process. Carbon nanofibers are disaggregated to the microcrystalline graphite and they are dispersed in NiO hexagonal structure (H–NiO sample). Microcrystalline graphite (1 wt% of the composite) has effect on growth NiO hexagonal nanoplates, improving the sample conductivity and stability. At the first cycle, H–NiO sample presents a high discharge capacity of 1357.2 mAh g−1 and a charge capacity of 1002.6 mAh g−1 with an initial coulombic efficiency of 73.9%. After 45 cycles, H–NiO sample exhibits a high reversible capacity of 1111.6 mAh g−1. The lithium diffusion coefficient of the H–NiO is calculated to be 7.517 × 10−12 cm2 s−1 with faster Li+ diffusion ability than pure NiO sample. The microcrystalline graphite in the composite electrode can effectively decrease the volume change and pulverization of NiO component, meanwhile, it hinders the aggregation in the cycled electrode. The microcrystalline graphite with intrinsic stability has potential application in producing composites with other metal oxides for highly reversible lithium storage capability. The as-produced microcrystalline graphite is in-situ composite with NiO hexagonal plates and play the key role in enhancement of electrochemical properties. The H–NiO nanoplates which is supported by microcrystalline graphite exhibits an excellent cycling stability, with a high reversible capacity of 1111.6 mAh g−1 at a current density of 100 mA g−1 after 45 cycles. Image 1 • Hierarchical hexagonal nanoplates NiO with microcrystalline graphite is synthesized. • Carbon nanofibers disaggregated to microcrystalline graphite and composite with NiO. • Microcrystalline graphite plays the key role in enhanced electrochemical properties. • H–NiO nanoplates presents discharge/charge capacities of 1357.2/1002.6 mAh g−1. • H–NiO exhibit reversible capacity of 1111.6 mAh g−1 after 45 cycles. [ABSTRACT FROM AUTHOR]

Metallic lithium (Li) is considered to be one of the most promising anodes for Li-ion batteries due to its high theoretical capacity and low reduction potential. However, dendritic growth and substantial volume variations during battery operation make it difficult for commercialization. Here, a graphene and SiO 2 composites material was presented as a lithiophilic host to enable superior long-term cycling for Li-metal anode. The porous skeleton of graphene with excellent electronic conductivity can effectively reduce the actual current density and suppress the volume expansion. And the SiO 2 particles with excellent ionic conductivity can significantly suppress the growth of Li dendrites and regulate the nucleation sites. So doping SiO 2 nanoparticles between graphene sheets can significantly suppress the growth of Li dendrites and the volume expansion effect of metallic Li deposition, while also providing good electrochemical performance. Benefitting from these synergistic effects, the Li-GF@SiO 2 battery exhibits excellent electrochemical reversibility over 500 cycles depositing 1 mAh cm−2 of metallic Li at a current density of 1 mA cm−2, and the coulombic efficiency of the Li-GF@SiO 2 battery is still as high as 97%, but the Li-Cu battery decays after 75 cycles. So this hierarchical SiO 2 -microsphere-graphene host demonstrates great potential for Li batteries. • The type of graphene and SiO 2 composite material is designed for the stable host of lithium (Li) metal anode because of its lithiophilic character. • The hierarchical silica spheres can effectively reduce the actual current density and guide the nucleation of Li metal. • The superior electronic conductivity and ionic conductivity of composite materials are utilized to suppress the growth of Li dendrites and volume expansion. • The novelty lithiophilic host of Li metal anode can achieve over 500 cycles at a current density of 1 mA cm−2 for Li-metal batteries. [ABSTRACT FROM AUTHOR]

Abstract In this work, a unique artificial interface combing characteristics of both high ionic and electronic conductivities has been successfully constructed at the surface of Ni-rich LiNi 0 · 8 Co 0 · 1 Mn 0 · 1 O 2 (NCM811). The ionic conductor layer is fabricated through reacting H 3 PO 4 with the lithium residuals on the surface of NCM811 to form Li 3 PO 4. The interface with high electronic conductivity is constructed by attaching graphene fragments to the NCM811 spherical particles. Due to the synergistic effect of the Li 3 PO 4 coating layer and the graphene network, the modified sample (GN-LPO-NCM811) exhibits high capacity retention of 94.3% after 150 cycles at 0.5C between 3.0 and 4.3 V, while the pristine material shows a much lower retention of only 88.1%. In addition, the GN-LPO-NCM811 also presents improved cycling stability at elevated temperature of 55 °C. Even at an extremely high rate of 10C, the GN-LPO-NCM811 still remains 70% of its original capacity, while the pristine NCM811 only delivers 50% of the capacity. The stable cycling performance of GN-LPO-NCM811 is demonstrated in a full cell with graphite anode at ambient temperatures. Importantly, the thermal stability of the modified samples is also greatly enhanced. This study provides an effective method to improve the electrochemical performance of LiNi 0 · 8 Co 0 · 1 Mn 0 · 1 O 2. Highlights • The residual Li species on the surface of NCM811 were transformed into Li 3 PO 4. • Build a mixed-conducting interlayer with fast ionic and electronic conductivities. • The modified samples show excellent cycling stability and high rate performance. • The performance of NCM811 was enhanced at both room and high temperature. • The mixed-conducting interlayer improves the thermal stability of NCM811. [ABSTRACT FROM AUTHOR]

• LiNiO 2 is investigated with a suitable oxygen partial pressure (p O 2) at calcination. • The calcination p O 2 only affects the surface of LiNiO 2 rather than the bulk. • Increasing p O 2 decreases the off-stoichiometry of LiNiO 2. • The LiNiO 2 calcined at the highest p O 2 has the 1st capacity of 239.8 mAh g−1 (93.4%). The electric vehicle (EV) market has grown tremendously in recent years, and is driving the development of lithium-ion batteries (LIBs) for energy storage. To meet the demand for high-energy–density and low-cost LIBs, Co-free and Ni-rich cathodes (e.g., LiNiO 2 ; LNO) and Si anodes are being investigated. However, drawbacks of LNO, such as cation mixing, processing challenges, and safety risks significantly limit its commercialization. Increasing the oxygen partial pressure (p O 2) during calcination of LNO has been shown to maintain its structural order and electrochemical performance. However, the mechanism by this observation is not well understood. In this research, three p O 2 conditions were applied during the calcination of LNO cathodes. The calcination p O 2 affects the sub-surface of LNO rather than the bulk region. Synchrotron spectroscopy and in-situ pressure analysis confirmed that Ni2+ and excess Li are present on the sub-surface of the LNO processed at the lowest p O 2. Increasing the p O 2 decreases the off-stoichiometry of LNO by providing additional oxygen to compensate for oxygen loss, especially at the sub-surface. A detailed mechanism by which the calcination p O 2 affects LNO is proposed. An LIB with the LNO cathode calcined at the highest p O 2 had a high initial capacity of 239.8 mA h g−1 (93.4 %), excellent fast charging cycle retention of half-cell and full cell at 55 °C, little gas evolution during cycling, and almost no weight change during storage in air. This calcining strategy prevents the cation mixing limitation of LNO, taking it one step closer to future EV application. [ABSTRACT FROM AUTHOR]

A novel one-dimensional CoMnO x /N-CNT composite was synthesized by binding Mn-Co nanoparticles on nitrogen doped carbon nanotubes (N-CNT) through solvothermal method and followed by high temperature pyrolysis. The as-made Mn-Co/N-CNT as LIBs anode material exhibits excellent rechargeable capability, i.e. 1028 mAh·g −1 at 200 mA·g −1 . Doped nitrogen on CNT effectively increase the conductivity of the complex and the binding energy between Mn-Co nanoparticles and CNT, which lead to more stable and higher conductive complex during charge/discharge cycling process. [ABSTRACT FROM AUTHOR]

Highlights: [•] We have synthesized the layered LiNi0.5Mn0.5O2−xF x (0⩽ x ⩽0.04) by hydroxide co-precipitation method. [•] The structure, morphology and electrochemical performance of LiNi0.5Mn0.5O2 are influenced by F doping effect. [•] The cations mixing of pure LiNi0.5Mn0.5O2 decreases and Li+ diffusion coefficient increases with doping F. [•] The reversible capacity of LiNi0.5Mn0.5O1.96F0.04 is 155.0mAhg−1 after 50 cycles at 0.2 C, 0.5 C and 1.0 C ratios between 2.8 and 4.6V. [ABSTRACT FROM AUTHOR]