Nanoparticle-assembled LiMn 2 O 4 hollow microspheres as high-performance lithium-ion battery cathode

Abstract Spinel LiMn 2 O 4 is an attractive cathode material for rechargeable lithium-ion batteries. However, its cycling and rate performance need further improvement. Herein, we present a novel LiMn 2 O 4 hollow microsphere cathode fabricated via a simple solid-state reaction utilizing MnO 2 hollow microspheres and LiOH H 2 O as the reactants. Interestingly, the as-prepared LiMn 2 O 4 hollow microspheres are assembled by LiMn 2 O 4 octahedral nanoparticles with exposed {111} planes, exhibiting abundant void spaces for the stress buffering and larger diffusion coefficient (1.570 × 10 −7 cm 2 s −1 ) for fast lithium ion transfer as compared to the simply aggregated LiMn 2 O 4 nanoparticles. As a result, the LiMn 2 O 4 hollow microspheres exhibit much improved cycling stability and deliver a specific discharge capacity of 86.3 mAh g −1 at a high rate of 10C, higher than that of the aggregated LiMn 2 O 4 (73.9 mAh g −1 ). Our work suggests that the electrochemical performance of LiMn 2 O 4 cathode can be manipulated by the design of unique hollow sphere structure.