Simple and inexpensive coal-tar-pitch derived Si-C anode composite for all-solid-state Li-ion batteries

A simple, inexpensive and scalable method to prepare silicon‑carbon composite particles for use in all-solid-state Li-ion battery anodes is presented. The composite's electrochemically active soft-carbon matrix is formed through the pyrolysis of coal-tar-pitch, an abundant industrial waste material. Various techniques are used to characterize the physical and electrochemical properties of this pitch derived carbon. Optimization of the Si-C composite anode resulted in an all-solid-state Li-ion half-cell displaying stable specific capacities of 653.5 mAh/g (per mass electrode) and 1089.2 mAh/g (per mass Si-C composite) after 100 discharge-charge cycles. Cross sectional images of cycled electrodes, prepared via FIB milling, were taken in order to investigate the effect of silicon particle expansion on their composite microstructures.