Hybridization of La _0.8 Sr _0.2 CoO ₃ Nanotubes With Graphene Quantum Dots Invigorating Bilateral Kinetics Toward Advanced Lithium–Sulfur Batteries

The practical application of lithium–sulfur batteries (LSBs) is impeded by sluggish redox kinetics of lithium polysulfides (LiPSs) and uncontrolled lithium dendrite formation. A dual‐functional separator modification strategy, where a perovskite‐based heterostructure (denoted as LSC@G) comprising La 0.8 Sr 0.2 CoO 3 (LSC) nanotubes and graphene quantum dots (GQDs) is conformally modified on both sides of a polypropylene separator, is proposed herein to address these challenges simultaneously through bilateral interfacial engineering. On the cathode side, the enhanced LiPSs adsorption and accelerated redox conversion are achieved via the synergistic combination of ferroelectric polarization from LSC and conductive networks provided by GQDs, thereby effectively suppressing LiPSs shuttling. On the anode side, polar O‐containing functional groups of GQDs create a lithiophilic interface that homogenizes Li + flux and promotes uniform Li deposition while inhibiting dendritic growth. To this end, LSBs equipped with this modified separator exhibit a high initial capacity of 857.6 mAh g −1 at 1 C alongside an ultralow capacity decay rate of 0.047% per cycle after 1000 cycles. Remarkable electrochemical performance is further demonstrated from 0°C to 50°C. These findings establish a generalizable paradigm for synchronously regulating cathode and anode interfacial kinetics in LSBs through rational heterostructure design.