Insight into the Catalytic Nature of Lithiophilicity for High-Energy-Density Lithium Metal Batteries

Designing dendrite-free lithium (Li) metal anodes for high-performance batteries requires a fundamental understanding of the substrate's lithiophilicity. Here, we systematically explore the electrochemical nucleation behavior of Li on various transition-metal substrates and uncover a substrate-dependent nucleation barrier that follows an inverted volcano-shaped curve, determined by the d-band center (ε_d) of these metals. Density functional theory calculations reveal that an optimal ε_d balances Li-atom adsorption and migration during Li nucleation, minimizing the nucleation barrier. To this end, we propose and validate the catalytic nature of lithiophilicity across diverse transition metal compounds. As a proof-of-concept, we modulate the electronic structure of CoP by incorporating Ni₂P, which downshifts the ε_d of CoP through electron redistribution at the CoP/Ni₂P heterointerface, thereby optimizing Li-atom adsorption and migration for enhanced lithiophilicity. This leads to the well-designed CoP/Ni₂P heterointerface-rich framework that enables selective bottom nucleation and effectively suppresses dendrite formation. The resulting framework demonstrates exceptional cycling stability, achieving 99.1% Coulombic efficiency over 450 cycles and 90.2% capacity retention after 100 cycles in a Li||LiFePO₄ pouch cell. This work revolutionizes our understanding of the catalytic nature of lithiophilicity and offers a pioneering approach for designing next-generation anodes for high-energy-density Li metal batteries.