Electrochemical and Nanomechanical Properties of TiO<sub>2</sub> Ceramic Filler Li‐Ion Composite Gel Polymer Electrolytes for Li Metal Batteries
Xiaona Pan, Peixia Yang, Yue Guo, Kejie Zhao, Baojuan Xi, Feng Lin, Shenglin Xiong
Abstract
Abstract Ionically conductive polymers are a promising family of electrolytes for electrochemical devices, including batteries, and flexible electronics. The polymer electrolytes with an excellent mechanical property probably can inhibit the dendrites growth during charging/discharging. Herein, the mechanical properties of an N −methyl− N −propyl piperidinium bis(trifluoromethanesulfonyl)imide/poly(vinylidene fluoride‐hexafluoropropylene) gel polymer electrolyte is improved through compositing with %TiO 2 nanoparticles. The gel polymer electrolyte shows increased loss modulus after compositing with 5 wt% TiO 2 , indicating that the inorganic nanoparticles can increase the viscous response of polymer electrolytes. The Li‐ion conductivity shows a noticeable dependence on %TiO 2 and the highest ionic conductivity is obtained at 5 wt% TiO 2 . The presence of TiO 2 in the gel polymer electrolyte also allows for smaller interfacial resistance and a more stable Li−electrolyte interface upon long‐term storage and battery cycling. As a result, when assembled with the LiFePO 4 and LiNi 0.6 Mn 0.2 Co 0.2 O 2 cathodes, the composite gel polymer electrolyte improves the full‐cell performance, such as higher Coulombic efficiency, improved cycling stability, and more stable electrode–electrolyte interface.