Microstructure and surface engineering through indium modification on Ni-rich layered cathode materials for enhanced electrochemical performance of lithium-ion batteries

Ni-rich layered lithium transition metal oxides have been considered as one of the most promising cathodes for next-generation lithium-ion batteries (LIBs) because of their high capacities and affordable costs. However, they still suffer bulk and surface structural instability, leading to rapid performance decay and subsequent cathode failure. In this context, Ni-rich layered cathodes with indium modified crystal and surface structures are developed by a simple one-pot calcination approach. Battery tests manifest that the indium modified LiNi0.8Co0.1Mn0.1O2 electrodes exhibit remarkably enhanced rate capability and cycling stability compared to the pristine one, including under high operating voltage condition. Further studies evidence a simultaneous mitigation of intra/inter-granular mechanical cracks and resistive surface films growth, which directly embodied in a dramatically suppressed ohmic loss after long-term cycling. The improved microstructural and surface stability are attributed by the synergistic functions of indium modification. On the one hand, trace amount of In3+ occupy crystalline Li+-site, which not only dissipate the intrinsic lattice strain during cycling, but also reduce Li+/Ni2+ antisite to avoid the undesired layer to rock-salt phase transformation. On the other hand, the rest of indium deplete lithium residues, and form conductive LiInO2 adherent coatings to protect the cathode from side reactions with electrolyte. The present work demonstrates that microstructure and surface engineering through indium modification offers a promising design strategy for further improvements of Ni-rich layered cathodes.