Enabling structural and interfacial stability of 5 V spinel LiNi0.5Mn1.5O4 cathode by a coherent interface

Spinel LiNi0.5Mn1.5O4 (LNMO), a 5 V class high voltage cathode, has been regarded as an attractive candidate to further improve the energy density of lithium-ion battery. The issue simultaneously enabling side stability and maintaining high interfacial kinetics, however, has not yet been resolved. Herein, we design a coherent Li1.3Al0.3Ti1.7(PO)4 (LATP) layer that is crystally connected to the spinel LNMO host lattices, which offers fast lithium ions transportation as well as enhances the mechanical stability that prevents the particle fracture. Furthermore, the inactive Li3BO3 (LBO) coating layer inhibits the corrosion of transition metals and continuous side reactions. Consequently, the coherent-engineered LNMO-LATP-LBO cathode material exhibits superior electrochemical cycling stability in a window of 3.0–5.0 V, for example a high-capacity retention that is 89.7% after 500 cycles at 200 mA g−1 obtained and enhanced rate performance (85.1 mA h g−1 at 800 mA g−1) when tested with a LiPF6-based carbonate electrolyte. Our work presents a new approach of engineering 5 V class spinel oxide cathode that combines interfacial coherent crystal lattice design and surface coating.