题目：Mechanically Robust Gel Polymer Electrolyte for an Ultrastable Sodium Metal Battery
作者：Chengzhao Luoa, Tong Shena, Haoqing Jib, Dong Huanga, Jie Liub, Bingyu Keb, Yihan Wub,
Yu Chen,a,c* and Chenglin Yanb*
aSchool of Optoelectronic Science and Engineering and Collaborative Innovation Center of Suzhou Nano Science and Technology Soochow University Suzhou 215006, China
bSoochow Institute for Energy and Materials Innovations College of Physics Optoelectronics and Energy and Collaborative Innovation Center of Suzhou Nano Science and Technology Soochow University Suzhou 215006, China
cNational University of Singapore Suzhou Research Institute Dushu Lake Science and Education Innovation District Suzhou 215123, P. R. China
摘要：Sodium dendrite growth is responsible for short circuit and fire hazard of metal batteries, which limits the potential application of sodium metal anode. Sodium dendrite can be effectively suppressed by applying mechanically robust electrolyte in battery system. Herein, a new composite gel polymer electrolyte (GPE) has been designed and fabricated, mainly consisting of graphene oxide (GO) and polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP). With the addition of appropriate amount of GO content, the compressive Young’s modulus of 2wt%GO+PVDF-HFP (2-GPH) composite GPE has been greatly enhanced by a factor of 10, reaching 2.5 GPa, which is crucial in the suppression of sodium dendrite growth. As a result, uniform sodium deposition and ultra-long reversible sodium plating/stripping (over 400 h) at high current density (5 mA cm-2) have been achieved. Furthermore, as evidenced by molecular dynamics simulation, the GO content facilitates the sodium ion transportation, giving a high ionic conductivity of 2.3×10-3 S cm-1. When coupled with Na3V2(PO4)3 (NVP) cathode in a full sodium metal battery, a high initial capacity of 107 mA h g-1 at 1C (1C=117 mA g-1) is recorded, with an excellent capacity retention rate of 93.5% and high coulombic efficiency of 99.8% after 1100 cycles.