Macroscopic Displacement Reaction of Copper Sulfide in Lithium Solid‐State Batteries

Autor: A. L. Santhosha, Philipp Adelhelm, Jürgen Janek, Joern Kulisch, Felix H. Richter, Dominik A. Weber, Simon Randau, Nazia Nazer, Raimund Koerver, Torben Adermann
Rok vydání: 2020
Předmět:
Zdroj: Advanced Energy Materials. 10:2002394
ISSN: 1614-6840
1614-6832
DOI: 10.1002/aenm.202002394
Popis: Copper sulfide (CuS) is an attractive electrode material for batteries, thanks to its intrinsic mixed conductivity, ductility and high theoretical specific capacity of 560 mAh g−1. Here, CuS is studied as cathode material in lithium solid-state batteries with an areal loading of 8.9 mg cm−2 that theoretically corresponds to 4.9 mAh cm−2. The configuration of the cell is LiLi3PS4[CuS (70 wt%) + Li3PS4 (30 wt%)]. No conductive additive is used. CuS undergoes a displacement reaction with lithium, leading to macroscopic phase separation between the discharge products Cu and Li2S. In particular, Cu forms a network of micrometer-sized, well-crystallized particles that seems to percolate through the electrode. The formed copper is visible to the naked eye. The initial specific discharge capacity at 0.1 C is 498 mAh g(CuS)−1, i.e., 84% of its theoretical value. The initial Coulomb efficiency (ICE) reaches 95%, which is higher compared to standard carbonate-based liquid electrolytes for the same cell chemistry (≈70%). After 100 cycles, the specific capacity reaches 310 mAh g(CuS)−1. With the current composition, the cell provides 58.2 Wh kg−1 at a power density of 7 W kg−1, which is superior compared to other transition metal sulfide cathodes.
Databáze: OpenAIRE