An In Situ Polymerized Li‐S Battery Integrated with an Electrothermal Interlayer

Abstract Benefiting from the high theoretical energy density, low cost, and environmental protection, the lithium‐sulfur (Li‐S) battery is one of the most competitive candidates for the next generation of high‐energy‐density batteries. However, the rate and low‐temperature performances are poor due to the terrible dynamics of the S cathode. Herein, a four‐electrode Li‐S cell integrated with an electrothermal interlayer is designed to realize the internal heating. An electrothermal interlayer composed of Li _1.3 Al _0.3 Ti _1.7 (PO ₄ ) ₃ (LATP) and carbon nanotube (CNT) is prepared and displays fast, uniform, and adjustable heating ability under applied voltages of 15‐30 V. The interlayer is also conducive to improving the wetting ability and thermal stability of the separator. Meanwhile, the Li ⁺ ion conductivity and transfer number of the in situ polymerized electrolyte are enhanced after integrating the interlayer, especially at high temperatures.