An effective strategy for dendrite free Li metal anodes: Nickel foam decorated with high lattice-matching CoN and CoF₂ nanosheets for dense deposition

The notorious dendrite and infinite volume change seriously restrict the advancement of lithium metal anodes (LMAs), during the long-term process of stripping/plating. Herein, the nanosheets of metal fluoride (CoF₂) and metal nitride (CoN) with magnificent lithiophilicity on the nickel (Ni) foam are designed as the “regulator” to uniform the Li plating and build stronger solid electrolyte interface (SEI) layer for dendrite free LMAs. The Ni foam offers abundant space to receive deposited Li metal. The CoN nanosheets can guarantee the fast transfer of electrons, which provides a stable interface of Li⁺ reduction. Moreover, the nanosheet structure with lithiophilicity would accelerate the move of Li⁺ and decrease the nucleation barrier, due to the high lattice-matching of Li and CoN. Meanwhile, the CoF₂ could increase the content of F (LiF) in the SEI layer, which enhances the strength and avoids the destruction of SEI layer. With the cooperation of CoN and CoF₂, the composited anode (Li/NF@CNCF) exhibits ultra-long cycle performance (more than 1200 h) and fantastic structure stability at 1 mA·cm⁻² with 1 mAh·cm⁻². Based on the LiFePO₄ and Li/NF@CNCF, the full cells deliver excellent specifical capacity and steady coulombic efficiency. The strategy contributes an effective approach to alleviate the issues of lithium metal anodes in the field of LMAs.