FeS_2-lmbedded Mixed Conducting Matrix as a Solid Battery Cathode

摘要

A new concept of pairing an active material and a mixed conductor is explored as a solid-state battery electrode. By imbedding nano-FeS2 domains into an amorphous LiTiS2 matrix, a hybrid power-energy system is achieved while additionally improving upon many common solid electrode design flaws. High-resolution transmission electron microscopy is used to probe the active material/mixed conductor interface over the course of cycling. Arguably the most beneficial development is enhancement of charge transfer, manifesting in a significantly increased exchange current as captured in a Tafel analysis. By developing a solution to active material isolation and creating a more homogenous electrode design, cycling at a high rate of C/2 for 500 cycles is obtained. Additionally, the electrode can recover full capacity simply by reducing system rate. Capacity recovery implicates a lack of active material isolation, a common problem in solid-state batteries.