Mechanically-robust structural lithium-sulfur battery with high energy density

The development of structural batteries has been obstructed by the intrinsically low mechanical strength of battery materials inside. Here, we propose a multifunctional structural battery platform by deploying electrodeposition-like reactions to prepare for conformally-coated electrodes, together with carbon fabrics as the skeleton to endow them with mechanical robustness. As a proof of concept, the Li/S battery system based on the electrodeposition-like mechanism was introduced into the structural batteries for the first time. The Young's modulus of optimized sulfur and lithium electrodes reach 9.2 ± 1.2 GPa and 4.5 ± 0.6 GPa, respectively, 5–20 times higher than conventional electrodes. Additionally, a thermally stable composite separator combining boron nitride nanofiller with PVdF polymer (BN/PVdF) is rationally designed, which possesses high compressive strength over 180 MPa. The structural cell integrated with these structural components delivered an excellent lifespan under compression up to 20 MPa for 20 cycles at 0.2 C. Moreover, the structural Li/S cell in pouch configuration displays better resistance to mechanical deformation when compared to the regular Li/S cell. This work provides valuable insight into structural batteries with high energy density.