The paradoxical role of rock-salt phases in high-nickel cathode stabilization: engineering a detrimental structure into a beneficial structure.

The surface phase formation of rock-salt in high-nickel layered oxide cathodes has conventionally been considered detrimental to electrochemical performance. Recent investigations, however, have revealed a more nuanced understanding wherein controlled formation of rock-salt phases during synthesis paradoxically enhances structural stability. This review critically examines the evolving paradigm of rock-salt formation in LiNiCoMnO ( ≥ 0.

Transformative Effect of Li Salt for Proactively Mitigating Interfacial Side Reactions in Sodium-Ion Batteries.

The robust respective formations of a solid electrolyte interphase (SEI) and pillar at the surfaces of hard carbon and O3-type positive electrodes are the consequences of integrating LiPF salt into a sodium-ion battery electrolyte that considerably strengthens both interfaces of positive and negative electrodes. The improvement of cycle performances due to the formation of highly passivating SEI on the hard carbon electrode is induced by the alternated solvation structure following the addition of Li salt, which inhibits sodium-ion and electron leakage from further electrolyte decomposition. The SEI with incorporated Li is less soluble than Na-based SEI, and the passivation ability of the initially formed SEI can thus be well preserved.

Levelized Electrode Utilization of Silicon-Enriched Pouch-Type Lithium-Ion Batteries from External Stress-Induced Overpotential Modulation.

The sectional utilization of the Si negative electrode resulted from the appropriate physical treatment of the pouch cell based on the distribution of electrical resistance. Active materials loaded near the tab have low electrical resistance, leading to a higher degree of lithiation in the Si near the tab. This localized utilization in large pouch cells causes significant polarization growth of the electrode due to mechanical and interphasial degradation.

Underlying Mechanism of Electrolyte Compositional Engineering Based on Additive Solvation-Structure Governing Solid Electrolyte Interphase Formation in Lithium-Ion Batteries.

Substantial efforts are dedicated to optimizing the additive dosage in the electrolyte and studying its effect on solid electrolyte interphase (SEI) formation in Li-ion batteries (LIBs). This study reveals that the decomposition characteristics of the additive based on its lithium-ion solvation nature significantly contribute to controlling SEI formation. During SEI formation, the strong lithium-ion solvating additive spontaneously migrates to the negative electrode due to negative charge accumulation on the surface, and SEI reinforcement is feasible by increasing the additive dosage.