Ultrahigh‐Voltage LiCoO 2 at 4.7 V by Interface Stabilization and Band Structure Modification

Abstract Lithium cobalt oxide (LCO) is widely used in Li‐ion batteries due to its high volumetric energy density, which is generally charged to 4.3 V. Lifting the cut‐off voltage of LCO from 4.3 V to 4.7 V will increase the specific capacity from 150 to 230 mAh g ‐1 with a significant improvement of 53%. However, LCO suffers serious problems of H1‐3/O1 phase transformation, unstable interface between cathode and electrolyte, and irreversible oxygen redox reaction at 4.7 V. Herein, interface stabilization and band structure modification are proposed to strengthen the crystal structure of LCO for stable cycling of LCO at an ultrahigh voltage of 4.7 V. Gradient distribution of magnesium and uniform doping of…

• GI
  Guangdong Innovative and Entrepreneurial Research Team Program

  Award: 2021ZT09L197
• NN
  National Natural Science Foundation of China

  Award: 52072205
• NK
  National Key Research and Development Program of China

  Award: 2019YFA0705703