Graphite as a potassium ion battery anode in carbonate-based electrolyte and ether-based electrolyte

By Liping Wang, Jingyi Yang, Jie Li, Ting Chen, Shulin Chen, Zhenrui Wu, J. Qiu, Bojun Wang, P. Gao, X. Niu and 1 more. Journal of Power Sources, 2019

223 citations recorded by the source corpus.

Abstract The graphite as the potassium ion battery anode is studied in KPF6-EC/DMC and KPF6-DME electrolytes. It is found that the graphite demonstrates superior rate performance with a capacity of 87 mAh g−1 at a current rate of 10 C (corresponding to 2.8 A g−1) and excellent capacity retention ability of 84% after 3500 cycles in DME-based electrolyte. Moreover, its initial coulombic efficiency is 87.4%, higher than 69.6% in EC/DMC-based electrolyte. The K+ solvating with DME complexes co-intercalate into graphite leading a high operational voltage at ∼0.7 V vs. ∼0.2 V in carbonate-based electrolyte, a fast apparent K+ diffusion coefficient of 10−8 cm2 s−1, a negligible solid-electrolyte interface film, a small volume expansion (7.7% in (002) plane vs. 63% in EC/DMC electrolyte). This study addresses the importance of electrolyte in altering the potassium storage mechanisms to tune the energy density and power density in potassium ion batteries (KIBs).

Subfields: Automotive Engineering, Electrical and Electronic Engineering

View Paper: https://www.semanticscholar.org/paper/acb29cf265564c2b4445adf8102e48b79269cc9a