Pseudocapacitive Enrichment of Interfacial Lithiophilicity for Anode-Free Lithium-Hydrogen Gas Battery

The emerging Li//H₂ battery is a promising candidate for energy storage systems to meet the demand for the worldwide transition to clean and sustainable energy. To leverage the H₂ electrode’s advantages and decrease costs, a high areal capacity anode-free Li anode is ideal. Here we propose using a pseudocapacitive Cu (PC-Cu) substrate to accommodate the high areal capacity anode-free Li//H₂ battery (AFLHB). The PC-Cu substrate exhibits intense electrochemical adsorption and intrinsic strong chemisorption to Li, which leads to aggregation of the Li salts so as to induce enrichment of interfacial lithiophilicity. This aids uniform Li nucleation, anion concentration, and robust SEI formation. The AFLHB displays stable cycling at a high areal capacity of 5 mAh cm⁻² with an average coulombic efficiency of 98.80% for over 350 h. Notably, the PC-Cu substrate enables superdense Li deposition with only 7% thickness exceeding the theoretical value. Moreover, the modified substrate enables a reversible Li stripping/plating at an ultralarge areal capacity of 20 mAh cm⁻². This work presents an interfacial lithiophilicity enrichment strategy to stabilize the cycling performance of high areal capacity AFLHB and advances this novel battery system one step closer to practical application.