Search Results (763)

Spinel LiNi_0.5Mn_1.5O₄ (LNMO) has emerged as a highly competitive cobalt-free cathode material for higher-energy-density lithium-ion batteries. However, its practical application is hindered by severe capacity degradation, particularly under high-voltage operation. To solve this problem, we put forward a surface modification strategy employing a Li_0.4La_0.54TiO₃ (LLTO) coating. The LLTO coating forms a protective cathode–electrolyte interphase that helps to inhibit interfacial side reactions, enabling enhanced electrochemical performance up to 5 V. As a result, the optimized 1 wt% LLTO-coated LNMO exhibits a remarkable capacity retention of 96.5% after 200 cycles at 0.1 C and delivers a high-rate capacity of 103.5 mAh g⁻¹ at 2 C, significantly outperforming its pristine counterpart (86.8% and 89.6 mAh g⁻¹, respectively). This work provides a viable and efficient surface modification approach for achieving robust high-voltage LNMO cathode material, underscoring its great potential for next-generation energy storage systems. Full article

Electrochemical energy storage systems are increasingly utilized across a wide range of applications, from small-scale consumer electronics to large-scale utility systems providing grid services. Among these, lithium-ion batteries have emerged as a preferred solution because of their high efficiency and power density. However, accurately modeling the behavior of Li-ion cells remains a critical and complex task. It is particularly important to determine the open-circuit voltage (OCV), which is an essential component of most battery models. This paper presents the results of an experimental comparison of three common methods for measuring and estimating the OCV of lithium-ion cells with nickel–manganese–cobalt cathodes. Each method is described in detail, with particular attention given to the testing procedures and influence of the experimental parameters on the accuracy of the resulting OCV curves. The outcomes are then analyzed and compared to highlight the strengths, limitations, and practical considerations associated with each approach. The findings of this work will assist researchers and practitioners in selecting the most appropriate OCV measurement techniques for various applications, especially where time constraints or experimental limitations must be considered. Full article

Electrolyte degradation and trace water contamination critically affect the lifetime and safety of lithium-ion batteries. In organic-based electrolytes such as acetonitrile (MeCN), even small amounts of water can trigger ${\mathrm{PF}}_6^{-}$ hydrolysis, producing HF, POF₃, and related species that contribute to electrolyte ageing and alter interfacial reactions. This study explores the electrochemical signatures of ageing and moisture contamination in Bu₄NPF₆- and LiPF₆-based MeCN electrolytes through a systematic cyclic voltammetry protocol. Platinum electrodes with different surface morphologies—flat, Nafion-coated, and nanostructured—were compared to assess their sensitivity to water-induced degradation. Cathodic Faradaic currents appearing around −0.7 to −1.0 V vs. Ag/AgCl were attributed to the protonic species generated by ${\mathrm{PF}}_6^{-}$-induced hydrolysis. The presence of LiPF₆, commonly used in battery electrolytes, further increases the concentration of anions responsible for the protonic species, therefore contributing to the acceleration of the electrolyte degradation. Experiments using a Nafion proton-conductive membrane assess the protonic origin of these peaks. Meanwhile, nanostructured platinum exhibits approximately four times higher current responses and enhanced sensitivity to water additions, reflecting the influence of surface roughness and active area. Overall, the findings indicate that electrode morphology significantly influences the detectability of ageing- and water-driven reactions, supporting the potential of nanostructured Pt as a diagnostic material for in situ monitoring. Full article

With the wide application of lithium-ion batteries (LIBs), many spent LIBs will face the problem of recycling and treatment in the future. The recycling of valuable substances from battery materials is particularly important. In this paper, the spent LiNi_0.5Co_0.2Mn_0.3O₂ (S-NCM523) cathode material from used LIBs was regenerated by using the eutectic lithium salt of Li₂CO₃/LiOH. The lithium element lost by S-NCM523 was supplemented through solid–liquid contact with the molten lithium salt, restoring the layered structure at high temperatures. The successful repair of the regenerated material was verified by various characterization methods, including the elimination of the rock salt phase and the lower Li⁺/Ni²⁺ disorder. This research shows that the regenerated cathode material still has a high specific discharge capacity of 146.8 mAh/g after 100 cycles, with a capacity retention rate of 96.0%. The excellent electrochemical performance of the regenerated material demonstrates the feasibility of directly regenerating spent NCM using the molten salt method. Full article

The development of lithium-ion batteries necessitates cathode materials that possess excellent mechanical and thermal properties in addition to electrochemical performance. As a prominent functional ceramic, the properties of spinel LiMn₂O₄ are governed by its atomic-level structure. This study systematically investigates the impact of Ni doping concentration on the mechanical and thermal properties of spinel LiNi_xMn_2−xO₄ via first-principles calculations combined with the bond valence model. The results suggest that when x = 0.25, the LiNi_xMn_2−xO₄ shows excellent mechanical properties, including a high bulk modulus and hardness, due to the favorable ratio of bond valence to bonds length in octahedra. Furthermore, this optimized composition shows a lower thermal expansion coefficient. Additionally, Ni doping concentration has a very minimal influence on the maximum tolerable temperature of the cathode material during rapid heating. Therefore, from the perspective of mechanical and thermal properties, this composition could be beneficial for improving the cycling life of the battery, since comparatively inferior mechanical properties and a higher thermal expansion coefficient make it prone to microcrack formation during charge–discharge cycles. Full article

Ni-rich layered LiNi_0.6Co_0.2Mn_0.2O₂ (NCM622) cathodes are the most promising candidates for high-energy lithium-ion batteries, but their performance is often limited by structural instability and capacity fading due to large primary particle sizes and surface degradation. Precise control of the primary particle size significantly impacts the performance of NCM622 cathodes and can mitigate fatigue mechanisms, but the underlying processes remain unclear. In this study, NCM622 cathodes with various primary particle sizes were synthesized by applying a controlled co-precipitation strategy by systematically controlling the ammonia feed rate and solution pH during precursor formation. Interestingly, higher ammonia feed rates promoted the formation of smaller, more ordered primary particles, whereas lower feed rates and reduced pH produced larger primary particles in spherical secondary structures. Electrochemical evaluation revealed that cathodes composed of smaller primary particles exhibited enhanced Li⁺ diffusion kinetics and superior electrochemical performance compared to those synthesized under lower ammonia feeding or reduced pH conditions. Moreover, the optimized NCM622 electrode demonstrated excellent rate capability and maintained a stable layered microstructure during cycling, retaining ~86% of its initial capacity. These results demonstrate that fine-tuning the ammonia feeding conditions during co-precipitation provides a simple and effective approach to control primary particle growth, thereby improving the structural integrity and electrochemical durability of NCM622 cathode materials. Full article

The rapid growth of electric vehicles has increased the demand for lithium-ion batteries, highlighting the need for sustainable recycling of spent cathode materials. This study combines laboratory-scale leaching experiments and Material Flow Cost Accounting (MFCA) to compare citric, tartaric, and succinic acids for recovering Ni, Co, Mn, and Li. Under optimized conditions, citric acid achieved leaching efficiencies of 81.66% (Li), 76.05% (Co), 91.46% (Ni), and 98.94% (Mn) at a cost of USD 6.50 per 10 g battery; tartaric acid reached 87.29% (Li), 80.52% (Co), 95.79% (Ni), and 99.65% (Mn) at USD 17.23 per 10 g battery; succinic acid yielded 87.05% (Li), 73.82% (Co), 86.27% (Ni), and 99.12% (Mn) at USD 4.11 per 10 g battery. MFCA shows acid consumption dominates costs, suggesting reagent optimization and recycling could reduce expenses. These results provide a cost-oriented laboratory-scale perspective for selecting organic acids, while industrial feasibility requires further evaluation of scale-up, reagent regeneration, and process optimization. Full article

The exponential growth of lithium-ion batteries (LIBs) in electric vehicles and energy storage systems has amplified the urgent need for sustainable recycling strategies. Conventional pyrometallurgical and hydrometallurgical methods for LIB recycling are energy-intensive, chemically demanding, and fail to preserve the structural integrity of cath-ode materials. Closed-loop recycling, in contrast, enables the recovery of layered oxides with minimal processing steps, reducing environmental footprint and supporting a circular economy. This study provides a systematic comparison of two regeneration approaches—sol–gel synthesis and hydroxide co-precipitation—for closed-loop recycling of layered NCM (LiNi_xCo_yMn_zO₂) cathode materials recovered from spent LIBs. Spent cells were mechani-cally processed and leached using malic acid to recover Ni, Co, Mn, which were subsequently used to synthesize NCM622 cathode powders. The regenerated materials were characterized using SEM/EDX, XRD, and electrochemical testing in CR2032 coin cells. Both methods successfully produced phase-pure layered oxides with the R-3m structure, with distinct differences in structural ordering and electrochemical behavior. The sol–gel-derived NCM622 displayed higher crystallinity and reduced cation mixing, evidenced by an I(003)/I(104) ratio of 1.896 compared to 1.720 for the co-precipitated sample, and delivered a high initial discharge capacity of 170 mAh/g at 0.1 C. However, it exhibited significant capacity fade, retaining only 60 mAh/g after 40 cycles. In contrast, the co-precipitation route produced hierarchical porous spherical agglomerates that offered superior cycling stability, maintaining ~150 mAh/g after 40 cycles with lower polarization (ΔE_p = 0.16 V). Both materials demonstrated electrochemical performance comparable to commercial NCM. Overall, hydroxide co-precipitation emerged as the most industrially viable method due to scalable processing, compositional robustness, and improved long-term stability of regenerated cathodes. This work highlights the critical influence of synthesis route selection in LIB closed-loop recycling and provides a technological framework for industrial recovery of high-value NCM cathode materials. Full article

The recycling of spent lithium-ion batteries (LIBs) requires efficient and sustainable methods for recovering critical metals. In this study, the leaching behavior of LiCoO₂ cathode material obtained from spent LIBs was investigated in phosphoric acid, using copper powder recovered from waste LIBs as a reducing agent. Leaching experiments were conducted under various conditions (temperature, solid-to-liquid ratio, agitation rate) and compared with systems without copper. In the absence of copper, lithium and cobalt, recoveries after 30 min were approximately 77% and 23%, respectively. The addition of copper significantly enhanced leaching, achieving >96% recovery for both metals at 80 °C, with most extraction occurring within the first 30 min. Kinetic analysis using the shrinking core model indicated a mixed-control mechanism involving both surface chemical reaction and product layer diffusion. The calculated activation energies were 20.2 kJ·mol⁻¹ for lithium and 16.1 kJ·mol⁻¹ for cobalt. Solid residues were characterized by X-ray diffraction (XRD) and scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS). XRD results revealed that the composition of the residues varied with leaching temperature: Co₃O₄ was consistently detected, whereas Cu₈(PO₃OH)₂(PO₄)₄·7H₂O appeared only when leaching was performed above 50 °C. Thermodynamic calculations supported the reductive role of copper and provided insight into possible reaction pathways. These findings confirm the effectiveness of copper-mediated leaching in phosphoric acid and demonstrate that temperature strongly influences residue phase evolution, thereby offering valuable guidance for the design of sustainable LIB recycling processes. Full article

In recent years, circular economy principles have become a key paradigm in the design and evaluation of industrial processes, including recycling technologies. Direct recycling of used lithium-ion batteries is attracting particular attention, as it can significantly reduce energy consumption, reagent costs, and the carbon footprint of the entire process compared to traditional hydro- and pyrometallurgical methods. This paper provides an overview of the current state of knowledge, synthesizes contemporary methods of Li-ion battery cell recycling, and presents the most important achievements in the field of direct recycling, with particular emphasis on the regeneration and re-leaping of cathode materials, and discusses the implementation and economic premises. Key challenges and research gaps are also identified, including the need to use computational modeling (CFD/DEM, kinetic and data-driven models) to optimize the deactivation, separation, and regeneration stages. This review concludes that direct recycling has the potential to become the leading circular economy pathway for Li-ion batteries, provided that quality standardization and process modeling tools are developed in parallel. Full article

This review investigates how cell form factors (cylindrical, prismatic, and pouch) and electrode architecture (jelly-roll, stacked, and blade) influence the performance, safety, and manufacturability of lithium-ion batteries (LIBs) across the main commercial chemistries LiFePO₄ (LFP), Li (NiMnCo)O₂ (NMC), LiNiCoAlO₂ (NCA), and LiCoO₂ (LCO). Literature, OEM datasheets, and teardown analyses published between 2015 and 2025 were examined to map the interdependence among geometry, electrode design, and electrochemical behavior. The comparison shows trade-offs among gravimetric and volumetric energy density, thermal runaway tolerance, cycle lifespan, and cell-to-pack integration efficiency. LFP, despite its lower nominal voltage, offers superior thermal stability and a longer cycle life, making it suitable for both prismatic and blade configurations in EVs and stationary storage applications. NMC and NCA chemistries achieve higher specific energy and power by using jelly-roll architectures that are best suited for tabless or multi-tab current collection, enhancing uniform current distribution and manufacturability. Pouch cells provide high energy-to-weight ratios and flexible packaging for compact modules, though they require precise mechanical compression. LCO remains confined to small electronics owing to safety and cost limitations. Although LFP’s safety and affordability make it dominant in cost-sensitive applications, its low voltage and energy density limit broader adoption. LiMnFePO₄ (LMFP) cathodes offer a pathway to enhance voltage and energy while retaining cycle life and cost efficiency; however, their optimization across various form factors and electrode architecture remains underexplored. This study establishes an application-driven framework linking form factors and electrode design to guide the design and optimization of next-generation lithium-ion battery systems. Full article

Vibrational spectroscopy is one of the most powerful techniques available for the characterization of materials for Li-ion batteries (LIBs) and one of the most useful tools when X-ray diffraction is ineffective for amorphous substances. Raman spectroscopy is essentially a probe to examine the surface of compounds that strongly absorb visible light, which is the case for all electrode materials, while infrared spectroscopy is a tool that examines the entire volume of particles. The purpose of this review is to study the lattice dynamics of cathode, anode, and electrolyte materials of advanced LIBs, especially nanomaterials for high-power-density application. Ex situ and in situ analyses are presented, which satisfy several key issues, such as structural stability over long-term cycling. Full article

The growing consumption of lithium-ion batteries (LIBs) in electronic devices and electric vehicles has led to a significant increase in waste containing valuable metals such as lithium and cobalt. Recovering these metals is essential to reducing dependence on primary sources and minimizing environmental impact. In this study, the leaching of the cathode active material from discarded LIBs was evaluated using oxaline, a deep eutectic solvent (DES) composed of oxalic acid and choline chloride in a 1:1 molar ratio. The process began with the collection, discharge, washing, drying, and dismantling of the LIBs, followed by the separation of their components. Subsequently, the cathode active material was characterized, revealing a primary composition of cobalt (54.5%) and lithium (6.5%), with the presence of LiCoO₂ confirmed by XRD analysis. Leaching experiments were conducted to evaluate the effects of temperature, time, and solid percentage, demonstrating that oxaline is effective for the selective leaching of lithium and cobalt. Under optimal conditions (90 °C, 1–2 wt.% cathode active material, 400 rpm), lithium underwent complete dissolution within the first hour, while cobalt achieved complete leaching by 4 h. Both metals were recovered as oxalates and separated based on differences in solubility. Oxaline proves to be an efficient and environmentally friendly alternative for the selective recovery of lithium and cobalt from LIB waste, supporting a circular economy in the management of critical metals. Full article

While we are pursuing a fully electrified society, high-energy rechargeable batteries are undergoing intensive investigation. In this respect, atomic and molecular layer deposition (ALD and MLD) have been drawing increasing interest, due to their unmatched capabilities to precisely modify electrodes’ surfaces for better electrochemical performance. In this work, we reviewed the recent studies using ALD/MLD for interface engineering of several important electrode materials, including nickel (Ni)-rich metal oxide cathodes, silicon (Si), and lithium (Li) anodes in lithium-ion and lithium metal batteries. We particularly discussed the most promising coatings from these studies and explored the underlying mechanisms based on experiments and modeling. We anticipate that this work will inspire more studies using ALD/MLD as an important technique for securing new solutions for batteries. Full article

In this study, a rough-surfaced LiFePO₄ (RS-LFP) cathode material with a well-defined porous architecture was successfully synthesized via a scalable, template-assisted spray drying method. The resulting RS-LFP exhibited a high specific surface area of 41.2 m² g⁻¹, significantly enhancing electrode–electrolyte contact. This tailored microstructure, combined with an in-situ-formed carbon network, reduced the charge-transfer resistance and facilitated efficient ion/electron transport. Consequently, the RS-LFP demonstrated outstanding electrochemical performance, including a high initial capacity of ~140 mAh g⁻¹ at 0.2 C, excellent cycling stability with over 95% capacity retention after 30 cycles, and superior rate capability. The RS-LFP also exhibited a remarkable capacity recovery of ~99% when the current returned to 0.2 C. These findings highlight that engineering porous architectures through template-assisted spray drying is a promising and scalable strategy for developing high-performance phosphate-based cathodes for advanced energy storage applications. Full article