Investigation of Potassium Storage in Layered P3-Type K0.5 MnO2 Cathode

Haegyeom Kim; Dong-Hwa Seo; Jae Chul Kim; Shou-Hang Bo; Lei Liu; Tan Shi; Gerbrand Ceder

doi:10.1002/adma.201702480

Investigation of Potassium Storage in Layered P3-Type K_0.5 MnO₂ Cathode

Adv Mater. 2017 Oct;29(37). doi: 10.1002/adma.201702480. Epub 2017 Aug 7.

Authors

Haegyeom Kim¹, Dong-Hwa Seo², Jae Chul Kim¹, Shou-Hang Bo^{1

3}, Lei Liu⁴, Tan Shi², Gerbrand Ceder^{1

2}

Affiliations

¹ Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
² Department of Materials Science and Engineering, University of California, Berkeley, CA, 94720, USA.
³ University of Michigan-Shanghai Jiao Tong University Joint Institute, Shanghai Jiao Tong University, 800 Dongchuan Road, Minhang District, Shanghai, 200240, P. R. China.
⁴ Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.

PMID: 28782851
DOI: 10.1002/adma.201702480

Abstract

Novel and low-cost batteries are of considerable interest for application in large-scale energy storage systems, for which the cost per cycle becomes critical. Here, this study proposes K_0.5 MnO₂ as a potential cathode material for K-ion batteries as an alternative to Li technology. K_0.5 MnO₂ has a P3-type layered structure and delivers a reversible specific capacity of ≈100 mAh g^-1 with good capacity retention. In situ X-ray diffraction analysis reveals that the material undergoes a reversible phase transition upon K extraction and insertion. In addition, first-principles calculations indicate that this phase transition is driven by the relative phase stability of different oxygen stackings with respect to the K content.

Keywords: batteries; energy storage; layered compounds; potassium.