In situ electrolyte design: understanding the prospects and limitations of a high capacity Ca(BH4)2 anode for all solid state batteries

Chen, Y., Sakamoto, R., Inoishi, A., Okada, S., Sakaebe, H., Albrecht, K. and Gregory, D. H. (2024) In situ electrolyte design: understanding the prospects and limitations of a high capacity Ca(BH4)2 anode for all solid state batteries. Batteries and Supercaps, 7(4), e202300550. (doi: 10.1002/batt.202300550)

Abstract

All-solid-state batteries have gained considerable attention due to their high safety and energy density. However, solid state electrolytes which contribute to the ionic conductivity component of a composite electrode, are not utilized during the electrode reaction and cannot directly contribute to capacity. This study focuses on decreasing the amount of electrolyte in the electrode by utilizing Ca(BH4)2 as an active electrode material. In this work, the charge-discharge properties of Ca(BH4)2 as an electrode material were determined for the first time. The lithiation of the Ca(BH4)2 anode creates LiBH4 within the electrode mixture, providing new Li-ion conduction pathways within the composite electrode in situ. An electrode fabricated only from Ca(BH4)2 and acetylene black (AB) showed an initial capacity of 473 mAh g-1 at 120 °C, which is comparable to the performance obtained from a composite electrode additionally containing electrolyte. Evidently, Ca(BH4)2 is a promising candidate negative electrode for increased energy density all-solid-state Li-ion batteries.

• Item Type: Articles
• Additional Information: This work was in part supported by JSPS KAKENHI Grant Number JP20H05297, JP22H04621 (Grant-in-Aid for Scientific Research on Innovative Areas “Interface IONICS”), JST Grant Number JPMJFS2132 (the establishment of university fellowships towards the creation of science technology innovation), Grant-in-Aid for "2019 Initiative for Realizing Diversity in the Research Environment" through the "Diversity and Super Global Training Program for Female and Young Faculty (SENTAN-Q)", Kyushu University from MEXT and "Dynamic Alliance for Open Innovation Bridging Human, Environment and Materials" from the MEXT. D. H. G. thanks Kyushu University for support under the Progress 100 program.
• Keywords: All-solid-state battery, in situ electrolyte, negative electrode, Ca(BH4)2.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Gregory, Professor Duncan
• Authors: Chen, Y., Sakamoto, R., Inoishi, A., Okada, S., Sakaebe, H., Albrecht, K., and Gregory, D. H.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Batteries and Supercaps
• Publisher: Wiley
• ISSN: 2566-6223
• ISSN (Online): 2566-6223
• Published Online: 17 January 2024
• Copyright Holders: Copyright © 2024 The Authors
• First Published: First published in Batteries and Supercaps 7(4): e202300550
• Publisher Policy: Reproduced under a Creative Commons License