Significantly enhanced electrochemical properties of LiMn2O4-based composite microspheres embedded with nano-carbon black particles

Herein, we have successfully prepared the LiMn2O4-based composite microspheres embedded with nano-carbon black (VXC-72R) particles by using spray-drying technique with nanosized LiMn2O4 particles as host material and VXC-72R nanoparticles as dispersing agent. For this hybrid composite, LiMn2O4 nanoparticles contribute to the fast diffusion of lithium ions because of nanosized diffusion distance, and well-distributed VXC-72R nanoparticles not only enhance the electronic conductivity but also restrain the aggregation of LiMn2O4 nanoparticles. The low specific surface area of micro-sized composite microspheres can reduce the contact area between cathode material and electrolyte, which help to suppress the manganese dissolution in electrolyte to some extent. Because of the synergistic action of these advantages, the obtained LiMn2O4@VXC-72R composite exhibits high initial discharge capacity of 127.4 mAh g−1 with good cycling stability at 0.5 °C. After 100 cycles, the discharge capacity of composite cathode still reaches up to 120.1 mAh g−1, which is much higher than that of the primary LiMn2O4 particles. Moreover, the LiMn2O4@VXC-72R composite shows excellent high-rate capability and high-temperature performance.