Micro-scale Li2S–C composite preparation from Li2SO4 for cathode of lithium ion battery

• A new method is proposed to prepare microscale Li2S–C composite from Li2SO4.
• Multi-solvent recrystallization was utilized to prepare fine-grain Li2SO4.

A facile and scalable method is proposed to prepare microscale Li2S–C composite from Li2SO4 through carbon-thermal reduction, followed by a carbon coating process. Multi-solvent recrystallization was utilized to reduce the particle size of Li2SO4 to 2 μm. This fine-grain Li2SO4 helps to shorten the particle size of reduction product from 10 μm to 3 μm. Using fine Li2SO4 also brings the benefit of greatly reducing the over potential during the initial charge process and increasing the kinetics for Li2S materials. Finally, the microscale Li2S–C composite prepared from fine Li2SO4 enables a stable capacity of 350 mAh g-1 at 0.2 C, higher than that obtained using a cathode prepared from commercial Li2SO4.