Low-Cost High-Energy Potassium Cathode

Leigang Xue; Yutao Li; Hongcai Gao; Weidong Zhou; Xujie Lü; Watchareeya Kaveevivitchai; Arumugam Manthiram; John B Goodenough

doi:10.1021/jacs.6b12598

Low-Cost High-Energy Potassium Cathode

J Am Chem Soc. 2017 Feb 15;139(6):2164-2167. doi: 10.1021/jacs.6b12598. Epub 2017 Jan 31.

Authors

Leigang Xue¹, Yutao Li¹, Hongcai Gao¹, Weidong Zhou¹, Xujie Lü², Watchareeya Kaveevivitchai¹, Arumugam Manthiram¹, John B Goodenough¹

Affiliations

¹ Materials Science and Engineering Program and Texas Materials Institute, The University of Texas at Austin , Austin, Texas 78712, United States.
² Earth and Environmental Sciences Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.

PMID: 28125230
DOI: 10.1021/jacs.6b12598

Abstract

Potassium has as rich an abundance as sodium in the earth, but the development of a K-ion battery is lagging behind because of the higher mass and larger ionic size of K⁺ than that of Li⁺ and Na⁺, which makes it difficult to identify a high-voltage and high-capacity intercalation cathode host. Here we propose a cyanoperovskite K_xMnFe(CN)₆ (0 ≤ x ≤ 2) as a potassium cathode: high-spin Mn^III/Mn^II and low-spin Fe^III/Fe^II couples have similar energies and exhibit two close plateaus centered at 3.6 V; two active K⁺ per formula unit enable a theoretical specific capacity of 156 mAh g^-1; Mn and Fe are the two most-desired transition metals for electrodes because they are cheap and environmental friendly. As a powder prepared by an inexpensive precipitation method, the cathode delivers a specific capacity of 142 mAh g^-1. The observed voltage, capacity, and its low cost make it competitive in large-scale electricity storage applications.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.