Lithium Metal-Copper Vanadium Oxide Battery with a Block Copolymer Electrolyte. Issue 10 (1st January 2016)

• Record Type: Journal Article
• Authors: Devaux, Didier; Wang, Xiaoya; Thelen, Jacob L.; Parkinson, Dilworth Y.; Cabana, Jordi; Wang, Feng; Balsara, Nitash P.
• Is Part Of: Journal of the Electrochemical Society. Volume 163:Issue 10(2016)
• Page Start: A2447
• Page End: A2455
• Publication Date: 2016-01-01
• Subjects: block copolymer -- copper vanadium oxide -- lithium battery -- X-ray diffraction -- X-ray tomography; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.1331610jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : Lithium (Li) batteries comprising multivalent positive active materials such as copper vanadium oxide have high theoretical capacity. These batteries with a conventional liquid electrolyte exhibit limited cycle life because of copper dissolution into the electrolyte. We report here on the characterization of solid-state Li metal batteries with a positive electrode based on α-Cu6.9 V6 O18.9 (α-CuVO3 ). We replaced the liquid electrolyte by a nanostructured solid block copolymer electrolyte comprising of a mixture of polystyrene- b -poly(ethylene oxide) (SEO) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt. In situ X-ray diffraction was used to follow the Li insertion/de-insertion mechanism into the α-CuVO3 host material and its reversibility. In situ X-ray scattering revealed that the multistep electrochemical reactions involved are similar in the presence of liquid or solid electrolyte. The capacity fade of the solid-state batteries is less rapid than that of α-CuVO3 –Li metal batteries with a conventional liquid electrolyte. Hard X-ray microtomography revealed that upon cycling, voids and Cu-rich agglomerates were formed at the interface between the Li metal and the SEO electrolyte. The void volume and the volume occupied by the Cu-rich agglomerates were independent of C -rate and cycle number.