Polycrystalline Ni-rich layered oxides are promising cathodes for Li-ion batteries of high-power density and long cycle life. However, their practical application is still hindered by the sluggish Li+ diffusion rate and reaction inhomogeneity during redox cycles. In this work, LiNi0.9Co0.05Mn0.05O2 (NCM9055) cathode with a desired internal radial structure was designed and successfully synthesized using Nb2O5 as a dual-functional structural and interfacial modulator. During calcination, the Nb2O5 reacts to form an intergranular LiNbO3 phase at grain boundaries. This phase, forming before high-temperature grain growth, acts as a structural modulator to preserve the desirable radial alignment of primary particles by impeding random grain growth. It also functions as an interfacial conductor, creating fast Li+ diffusion pathways along the grain boundaries. These structural and interfacial modifications synergistically mitigate chemical inhomogeneity and relieve accumulated strain during cycling. Consequently, the Nb-modified NCM9055 exhibits superior electrochemical performance, delivering an excellent rate capacity (152.4mAhg- 1 at 10C) and robust cycling stability under high-rate conditions (83.0% capacity retention after 500 cycles at 5C). These findings clarify the mechanism of Nb modulation and demonstrate a robust strategy for preserving desirable microstructures in high-rate, Ni-rich cathode materials.

Co-doped LiMn0.4Fe0.6PO4@C via two-step synthesis for advanced Li-Ion battery cathodes

Incorporating silicon‐based active materials, e.g., SiOx, into the negative electrodes can increase the gravimetric/volumetric energy of Li ion batteries. Nevertheless, SiOx shortens cycle life due to the large volume expansion during charge/discharge cycling. The mechanical stress on the solid electrolyte interphase (SEI) necessitates continuous SEI repair, which accelerates active lithium loss (ALL) over cycling. In this work, the impact of common lithium salts is investigated in electrolytes for LiNi0.5Co0.2Mn0.3O2 (NCM 523) || 10%SiOx‐graphite Li ion pouch cells. The end‐of‐life (EOL) with LiPF6 can be enhanced by anode passivation via fluoroethylene carbonate (FEC), which not only decreases ALL but also suppresses failure cascades (e.g., electrode crosstalk) initiated by HF over the course of SiOx reactions with LiPF6. Though ALL remains similar when adding FEC to lithium bis(oxalato)borate (LiBOB), it enhances the generation of active Li through oxidation reactions at the cathode, likely due to the inverse crosstalk of partly soluble SEI species. This “self‐healing” or “recovery” mechanism reactivates the apparently “wasted SEI” and formerly lost capacity, thereby enhancing cycle life. This positive effect is even more pronounced with LiDFOB. However, the accompanying gassing of the oxalato‐based salts remains an obstacle to practical applicability.

Lithium-rich manganese-based layered oxides (LRMOs) are promising cathodes for high-energy-density Li-ion batteries. However, their cycle life is highly limited by gas release and Mn dissolution in liquid electrolytes. All-solid-state batteries (ASSBs) could overcome these issues by using solid electrolytes, provided that a stable cathode-catholyte interface is maintained. A key challenge is that the capacity of conventional polycrystalline LRMOs is difficult to activate in ASSBs due to the sluggish kinetics of anionic redox-limiting Li diffusivity. We demonstrate here that, by using monolithic LRMO particles without any surface modification, oxygen redox can be largely activated, enabling a capacity of 268.4 mAh g-1, in stark contrast with ∼70 mAh g-1 of conventional polycrystalline particles. We attribute this enhancement to improved cathode-electrolyte contact and a shortened Li+ diffusion pathway in the monolithic cathode microstructure. Our work provides a crucial step toward practical LRMO-based ASSBs by tailoring cathode microstructure in addition to interface engineering.

Abstract Lithium-ion batteries play an essential role in various applications, from portable consumer electronics to electric vehicles and energy storage systems but their safety remains a major concern for manufacturers and users. Understanding the thermal runaway (TR) phenomenon and the factors that influence it has therefore received considerable scientific attention. This study focuses on the impact of the experimental setup on the TR parameters. To investigate this, the TR behavior of an NMC 811 cell was tested in two setups with different volumes under two environmental conditions: air and vacuum that represent two extreme conditions for a closed calorimeter. In each case, the same methodology was applied, by heating the cell at 6 °C min −1 , and the measured and calculated parameters were compared between setups. Understanding the effects of the experimental device under different environmental conditions is essential to draw clear conclusions about the potential risks of Li-ion cells. Results show that both configurations give similar trend in the evolution of TR time, cell temperature at venting and TR, and the amount of gas ejected. The mass loss is affected by the setup. The composition of the ejected gases depends on the setup and cell environment. The TR energies measured in the large volume under vacuum were comparable to those in the small volume under air/vacuum, probably due to limited quantity of oxygen in both cases. This study provides a new perspective into TR behavior of Li-ion cell by exploring the impact of the setup and its environment.

Effect of recycled content on the environmental footprint of new EV batteries.

3D-printed grid-patterned cathodes with MOF protective layers for enhanced ion diffusion and energy density in Li-ion batteries

Finite-element structural modelling of laser welds. Application to aluminium connections in Li-ion prismatic batteries

Recycling spent Li-ion batteries into functional nanomaterials for energy systems

Direct measurement of heat generation in a cylindrical Li-ion battery using heat flux sensors

From cell to module: An integrated approach to identification, modeling, simulation, and experimental validation of 21,700 Li-ion batteries for electric vehicles

Comprehensive assessment of two stage thermoelectric generators for cylindrical li-ion battery thermal management: Energy, environmental, and economic perspectives

Dispersion optimization of Si nanoparticles in Si@SiOC composites via ascorbic acid for high-performance Si-based Li-Ion batteries

Improving cooling efficiency of rectangular li-ion batteries using hybrid-nanofluid-based mini-channel cold plates

A comprehensive fundamental study of static immersion cooling of Li-ion battery: Experiments to data-driven model

Multi-method fusion estimation of state of charge for Li-ion batteries based on model-data dual-driven approach

Valuable metals recovery from spent Li-ion batteries via a carbon thermal reduction combined with oxidative acidic leaching process

Assessing second-life li-ion batteries for hybrid PV-diesel systems in remote amazonian communities

Impact of deformation on electrochemical impedance spectroscopy analysis methods and continued operation of Li-ion batteries

Maximizing the doping effect of Al in LiNixCoyMn1-x-yO2 cathode active materials for Li-ion batteries