Enabling interfacial stability of LiCoO2 batteries at an ultrahigh cutoff voltage ≥ 4.65 V via a synergetic electrolyte strategy. Issue 7 (1st February 2023)

• Record Type: Journal Article
• Authors: Fu, Ang; Xu, Chuanjing; Lin, Jiande; Su, Yu; Zhang, Haitang; Wu, De-Yin; Zhang, Xiaozheng; Xia, Meng; Zhang, Zhongru; Zheng, Jianming; Yang, Yong
• Is Part Of: Journal of materials chemistry. Volume 11:Issue 7(2023)
• Page Start: 3703
• Page End: 3716
• Publication Date: 2023-02-01
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d2ta09876h
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : A 3-dimethylmaleic anhydride (DMMA) additive is proposed to reconcile CEIs, and H2 O/HF in electrolytes is well scavenged. Moreover, a synergetic electrolyte strategy is applied to push the cutoff voltage of LiCoO2 batteries up to 4.7 V. Abstract : Elevating the cutoff charge voltage (≥4.65 V) of LiCoO2 (LCO) arouses a big challenge between the pursuit of high energy density and long cycling life of LCO-based batteries. Herein, 2, 3-dimethylmaleic anhydride (DMMA) as a novel electrolyte additive not only serves as a sacrificial agent to construct a robust and stabilized CEI film enriched with inorganic species (LiF, PO2 −, etc. ) but also removes the trace amounts of H2 O in electrolytes and prevents further decomposition of carbonate-based electrolytes and erosion of LCO. Several advanced characterization techniques such as AFM, XPS, HRTEM, and TOF-SIMS combined with theoretical calculations were applied to reveal the functioning mechanism. It was shown that at a cutoff voltage of 4.65 V, LCO cathode retains 81.6% of its initial capacity (215 mA h g −1 ) after 300 cycles and 70.7% after 500 cycles at 1C in the presence of 1% DMMA. Moreover, fluoroethylene carbonate (FEC), 1, 3, 6-hexanetricarbonitrile (HTCN) and DMMA-containing electrolytes are able to further enhance the high-voltage stability of LCO. LCO delivers a high capacity retention of 75.9% after 300 cycles at 4.7 V using the upgraded electrolyte. The synergistic strategy of multiple additives paves a new way to promote the durability of LCO at ultrahigh voltages as well as LCO-based batteries with high energy density.