Microstructure- and Interface-Modified Ni-Rich Cathode for High-Energy-Density All-Solid-State Lithium Batteries

Electric vehicles powered by Li-ion batteries pose a potential safety risk because the flammable liquid electrolytes can, under certain conditions, cause explosions. All-solid-state batteries (ASSBs) are safe alternative battery technologies. However, realizing high-energy-density ASSBs by employing Ni-rich layered cathodes is difficult because of the detrimental volume contraction near charge end. This study shows that the simultaneous B doping and coating of a Ni-rich LiNi0.9Co0.05Mn0.05O2 cathode, which modifies the cathode microstructure and cathode–solid electrolyte interface, respectively, afford an ASSB that cycles stably for 300 cycles with minimal capacity fading. An ASSB featuring the B-doped, B-coated LiNi0.9Co0.05Mn0.05O2 cathode demonstrates a discharge capacity of 214 mAh g–1, which represents one of the highest discharge capacities achieved by an ASSB; moreover, the ASSB retains 91% of its initial capacity after 300 cycles and easily outperforms previously reported ASSBs in terms of energy density without compromising cycling stability.