Spinel LiNi0.5Mn1.5O4 shell enables Ni-rich layered oxide cathode with improved cycling stability and rate capability for high-energy lithium-ion batteries

•Core-shell structure Ni-rich layered oxides is prepared for lithium-ion batteries.•Spinel LiNi0.5Mn1.5O4 shell enhances the structural and thermal stability of LiNi0.9Co0.1O2.•LiNi0.5Mn1.5O4 shell endows composite material with superior cyclability and rate capability.•LiNi0.5Mn1.5O4 shell ameliorates the high-voltage charging capability and thermal stability.