Facile Fabrication and Low-cost Coating of LiNi_0.8Co_0.15Al_0.05O₂ with Enhanced Electrochemical Performance as Cathode Materials for Lithium-ion Batteries

摘要

The electrochemical performance of LiNi0.8Co0.15Al0.05O2 (NCA) was improved by coating with lithium boron oxide (LBO) via an effective, simple and low-cost method, where H3BO3 reacts with residual Li2CO3/LiOH on the surface of NCA to form LBO. LBO-coated NCA (LBO-NCA) had a better cycling stability and rate capability than bare NCA. After 50 cycles at 1C rate, 95.1% of the discharge capacity of LBO-NCA was retained, corresponding to 155 mAh g-1, whereas bare NCA showed a discharge capacity retention of only 84.5%. In addition, LBO-NCA showed a discharge specific capacity of 153 mAh g-1 and 140 mAh g-1 at 2C and 5C, respectively, compared with bare NCA, which showed 145 mAh g-1 and 128 mAh g-1. The improvement in the rate capability of LBO- NCA is mainly attributed to the LBO coating layer greatly decreasing the charge-transfer resistance.