A highly stabilized nickel-rich cathode material by a nanoscale epitaxy control for high-energy lithium-ion batteries

Junhyeok Kim, Hyunsoo Ma, Hyungyeon Cha, Hyomyung Lee, Jaekyung Sung, Minho Seo, Pilgun Oh, M Park, Jaephil Cho

Index: 10.1039/C8EE00155C

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Abstract

Advanced surface engineering for the nickel-rich cathode materials greatly enhances structural/thermal stability. However, their application into the lithium-ion full-cell have still challenge such as unstable solid electrolyte interphase (SEI) layer on the anode. Herein, we reveal that the degradation of battery cycle life is caused by the release of divalent nickel ions from the LiNi0.8Co0.1Mn0.1O2 cathode and the formation of nickel metal particles in the graphite anode surface, deteriorating the anode SEI layer and its structural integrity. On the basis of this finding, we demonstrate a stable lithium-ion battery by modifying the cathode surface by creating nanostructured stabilizer with epitaxial structure that enhances the morphological robustness. During cycling, the nickel defect in the cathode is significantly suppressed, preventing nickel ion crossover. In particular, the anode SEI layer maintains uniform and dense structure, leading to outstanding cycle stability in the full-cell with capacity retention of ~86% after 400 cycles at 25°C.