Concentration-optimized boron surface modification for single-crystal high-nickel cathode stabilization

초록

Single-crystal high-nickel layered oxide cathodes exhibit surface instability mechanisms that limit electrochemical performance despite superior structural coherence. This investigation establishes concentrationdependent boron modification through controlled lithium extraction to create stable interfacial architectures. Systematic characterization reveals that moderate boron loading generates lithium borate surface phases while preserving layered structure integrity, whereas excessive incorporation triggers widespread rock-salt formation. Chemical analysis demonstrates progressive evolution from surface boron oxide species to lithium-enriched compounds, establishing critical loading thresholds for optimal modification. Extended cycling evaluation confirms enhanced stability through suppressed electrolyte decomposition and maintained structural coherence. The framework provides quantitative relationships between boron concentration and surface reconstruction behavior, enabling rational design of cathode surface engineering strategies. These findings demonstrate that controlled chemical modification achieves simultaneous structural stabilization and interfacial passivation, advancing fundamental understanding of surface chemistry optimization in high-energy-density cathode materials for lithium-ion batteries.

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