Enabling All‐Solid‐State Li Metal Batteries Operated at 30 °C by Molecular Regulation of Polymer Electrolyte. Issue 10 (20th January 2023)

• Record Type: Journal Article
• Authors: Wei, Ying; Liu, Te‐Huan; Zhou, Wenjiang; Cheng, Hang; Liu, Xueting; Kong, Jia; Shen, Yue; Xu, Henghui; Huang, Yunhui
• Is Part Of: Advanced energy materials. Volume 13:Issue 10(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-01-20
• Subjects: high ionic conductivity -- ion coordination -- PEO‐based electrolytes -- room temperature -- solid‐state batteries; Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.202203547
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract: The low ionic conductivity of poly(ethylene oxide) (PEO)‐based polymer electrolytes at room temperature and the undesired lithium‐dendrite growth at Li|PEO interface impede their further application. Herein, a PEO polymer is regulated at the molecular level through a copper ion (Cu 2+ ) coordination effect with both PEO and Li salts to achieve a high Li + conductivity of 0.2 mS cm −1 and a transference number of 0.42 at 30 °C. Moreover, the Cu‐coordinated PEO electrolyte is neither sticky nor hygroscopic because the hydrophilic oxygen groups in PEO are terminated by Cu ions. Furthermore, the in situ formed F/Li‐rich inorganic layer induced by CuF2 additive accelerates Li + transport kinetics and enables uniform Li + deposition during Li plating/stripping. As a result, the Cu 2+ ‐coordinated PEO electrolytes deliver a high critical current density of 1.5 mA cm −2 at 30 °C. An all‐solid‐state Li‐LiNi0.83 Co0.12 Mn0.05 O2 (NCM83) battery with such a copper coordinated PEO electrolyte exhibits a long cycle life over 500 cycles with a capacity retention of 71% under 0.6 C at 30 °C. When the mass loading increases to a record high of 7 mg cm −2, the Li‐NCM83 cell delivers a high areal capacity of 1.07 mAh cm −2 under 0.1 C at 30 °C. Abstract : A molecular regulation poly(ethylene oxide) (PEO) electrolyte is prepared through a Cu 2+ ‐coordination effect with both PEO and LiTFSI, which is stable in moist air and presents high ionic conductivity, transference number, and mechanical strength due to the coordinated 3D structure. Moreover, the coordinated PEO electrolyte shows superb cycling stability when employed in high‐voltage lithium‐metal batteries.