Nitrofullerene as an Electrolyte-compatible Additive for High-performance Sodium Metal Batteries
Pengju Li, Zhipeng Jiang, Xiaobo Huang, Xing Lu*, Jia Xie*, Shijie Cheng
Nano Energy, 2021.
https://doi.org/10.1016/j.nanoen.2021.106396
Abstract
Electrolyte additives have an important impact on the cycling stability of sodium metal batteries, but their applications are severely impeded by the poor compatibility with different electrolytes. Herein, rational incorporation of nitro groups on fullerene(C60) cage yields nitrofullerene (C60(NO2)6) as an effective additive, which displays high compatibility with different electrolytes and can enable highly reversible and dendrite-free plating/stripping of sodium metal anodes (SMAs).In-situ optical observationof Na electrodeposition confirms a great improvement in the cycling stability of metallic Na anodes with the C60(NO2)6additive, which not only promotes the formation of stable protective layers on SMAs, but also facilitates the uniform Na deposition and effectively suppresses the Na dendrite growth. As a result, the Na||Na symmetrical cells with C60(NO2)6show low voltage hysteresis, high rate capability and prolonged cycle life in both carbonate and ether electrolytes. Even at 5 mA cm–2and 5 mAh cm–2, the Na||Cu half cells can stably cycle over 450 h in the ether electrolyte. Furthermore, a significantly improved cycling stability of the high loading Na||Na3V2(PO4)3@C (8.7 mg cm–2) full cell is achieved in the carbonate electrolyte.
