Revitalizing lithium-mediated ammonia electrosynthesis activity over heterogeneous lithiophobic-lithiophilic solid electrolyte interphase

Compared to aqueous-phase electrocatalytic nitrogen reduction reaction (NRR), lithium-mediated NRR (Li-NRR) theoretically enhances the intrinsic activity of NH₃ production through spontaneous exothermic reactions between Li and N₂. However, the in-situ generated solid electrolyte interphase (SEI) during the reaction slows down the Li⁺ transport and nucleation kinetics, which further hinders the subsequent activation and protonation processes. Herein, a sophisticated amorphous-crystalline heterostructured SEI of Zn-LiF is formed by additive engineering. The concerted electron interplay between amorphous and crystalline domains is prone to generate lithiophobic Zn and lithiophilic LiF sites, where lithiophobic Zn accelerates Li⁺ diffusion within the SEI and avoids high concentration polarization, and lithiophilic LiF ensures homogeneous nucleation of diffused Li⁺ and its participation in subsequent reactions. Therefore, compared to conventional SEI, a more than 8-fold performance improvement is achieved in the additive-engineered heterogeneous lithiophobic-lithiophilic SEI, which exhibits a high NH₃ yield rate of 11.58 nmol s⁻¹ cm⁻² and a Faradaic efficiency of 32.97%. Thus, exploiting the synergistic effects in heterogeneous lithiophobic-lithiophilic structures to achieve functional complementarity between different components opens a new avenue toward high-performance Li-NRR.