Anchoring Interfacial Nickel Cations on Single-Crystal LiNi_0.8Co_0.1Mn_0.1O₂ Cathode Surface via Controllable Electron Transfer

Abstract

Severe Ni dissolution and the resulting impedance rise for the single-crystal LiNi0.8Co0.1Mn0.1O2 cathode is the main challenge greatly hindering its industrial applications. Herein, we propose a novel concept of anchoring interfacial nickel cations on a single-crystal LiNi0.8Co0.1Mn0.1O2 cathode through controllable electron transfer. This strategy is realized by applying an ultrathin PMMA surface layer. Different from traditional physical coatings, electron transfer from Ni2+ to the ester group is confirmed, which contributes to anchoring the interfacial Ni cations and effectively inhibits Ni dissolution into the organic electrolyte. Meanwhile, Li diffusion on the cathode surface is significantly improved. As a result, the electrochemical performance of the LiNi0.8Co0.1Mn0.1O2 cathode with a PMMA layer is improved. A reversible capacity of 181.1 mAh g–1 at 1C rate is obtained with enhanced rate capability and cycling stability. Moreover, the modified LiNi0.8Co0.1Mn0.1O2 is able to work well at high voltage and high temperature, especially with incorporation of polyvinylidene fluoride.