Toward High Temperature Sodium Metal Batteries via Regulating the Electrolyte/Electrode Interfacial Chemistries

作者：Xueying Zheng, Zhang Cao, Zhen‐Yi Gu, Liqiang Huang, Zhonghui Sun, Tong Zhao, Sijie Yu, Xing‐Long Wu, Wei Luo, Yunhui Huang · 发表于：ACS Energy Letters · 年份：2022 · DOI：10.1021/acsenergylett.2c01100 · 被引用次数：139 · 研究领域：Advanced Battery Materials and Technologies、Advancements in Battery Materials、Layered Double Hydroxides Synthesis and Applications

Rechargeable batteries based on sodium metal anodes (SMAs) are endowed with much higher energy density than traditional sodium-ion batteries. However, the use of SMAs brings intrinsic challenges of dendrite growth and unstable solid/electrolyte interphase (SEI) formation. This situation can be further exacerbated at high temperature (>55 °C, HT). Here, we resolve such “HT-challenge” by formulating a thermally stable sulfolane (SL)-based electrolyte that regulates the electrode/electrolyte interfacial chemistries. Besides rapid Na anode passivation enabled by fluoroethylene carbonate (FEC) molecules, a nitrile-based 1,3,6-hexanetricarbonitrile (HTCN) cosolvent is simultaneously introduced, whose three electron-rich -C≡ N groups interact with the electropositive metal ions of Na 3 V 2 (PO 4 ) 2 O 2 F, shielding away solvent attacks occurring at the cathode interface. As a result, we realize a high capacity retention (91.7% after 500 cycles at 1 C) for the Na/Na 3 V 2 (PO 4 ) 2 O 2 F cell at 60 °C, with a high average carbon equivalent (CE) of ∼99.6%. Even at 80 °C, the cell still delivers ∼89.1% of its initial capacity after 100 cycles, whereas the control sample fails rapidly within 30 cycles.