Jing Gao, Chunshui Sun, Lei Xu, Jian Chen*, Chong Wang, Decai Guo, Hao Chen, Lithiated nafion as polymer electrolyte for solid-state lithium sulfur battery using carbon-sulfur composite cathode. Journal of Power Sources, 2018, 382, 179-189

ABSTRACT

Due to flexible property and light weight, the lithiated Nafion membrane swollen with PC (PC-Li-Nafion) has been employed as both solid-state electrolyte and separator to fabricate solid-stateLi-Scells.The electrochemical measurements of PC-Li-Nafion membrane show that its Li-ion transference number is 0.928, ionic conductivity of 2.1×10−4Scm−1 can be achieved at 70 °C and its electrochemical window is 0 ∼ +4.1 V vs. Li+/Li. It is observed that the Li dendrites are suppressed by using PC-Li-Nafion membrane due to its single-ion conducting property. The amounts of Li-Nafion resin binder and conductive carbon in the cathode are optimized as 40% and 10% respectively to make a balance of ionic and electronic conductivities. A thin-layer Li-Nafion resin with a thickness of around 2μm is fabricated between the cathode and PC-Li-Nafion membrane to improve the interfacial contact and further enhance the specific capacity of the cell. When measured at 70°C, the Li-S cell delivers a reversiblespecificcapacity of1072.8mAhg−1(S)at 0.05Cand 895mAhg−1(S)at1C. The capacityretention at 1C is 89% after 100 cycles. These results suggest that high-performance solid-state Li-S cells can be fabricated with the Li-Nafion polymer electrolyte.

Keywords: Solid-state lithium sulfur cells Single-ion conductor Lithiated Nafion Carbon-sulfur composites Lithium anode Interlayer