Spray drying-assisted synthesis of hollow spherical Li2FeSiO4/C particles with high performance for Li-ion batteries

Improving the rate performance is still a major challenge for Li 2 FeSiO 4 cathode material for Li-ion battery. Herein, hollow spherical Li 2 FeSiO 4 /C microscale particles, consisting of carbon-coated primary nanoparticles (20–40   nm) have been fabricated by a spray drying-assisted method. The particle size of spherical Li 2 FeSiO 4 /C is 1–5   μm, which is suitable for commercial application. When used as a cathode material for Li-ion battery, the as-prepared Li 2 FeSiO 4 /C composite with 16.7   wt.% carbon exhibits a high discharge capacity of 165   mAh   g −   1 at 0.2   C rate. At 0.5   C, 5   C and 10   C rates, the capacities of 151   mAh   g −   1 , 111   mAh   g −   1 , and 96   mAh   g −   1 are observed, respectively, indicating superior rate performance. Meantime, good cycling stability is achieved with a capacity retention of 94.5% at a high current density of 2   C after 100   cycles. The excellent electrochemical performance is mainly ascribed to the improved ionic/electronic conductivity arising from the hollow spherical structure and carbon-coated primary nanoparticles . The spray drying process shows a great potential for the large scale production of high quality Li 2 FeSiO 4 /C composite.