Controlling Lithium Surface Diffusivity via 2D PtTe2, PdTe2, and NiTe2 Coatings for Anode‐Free and Lithium Metal Batteries

Abstract Anode‐free Li‐ion batteries (AFLBs) and Li‐metal batteries (LMBs) offer superior energy densities compared to conventional Li‐ion batteries with graphite anodes. However, they degrade faster owing to their lower Coulombic efficiency, primarily caused by uneven Li deposition on the current collector (CC) in AFLBs or the Li‐metal anode (LMA) in LMBs. Coating CCs and LMAs has emerged as a promising strategy to enhance the CE. Coating CCs and LMAs with PtTe 2 , PdTe 2 , and NiTe 2 —metallic 2D transition metal dichalcogenides—reveals the critical factors for achieving uniform Li plating. The PtTe 2 coating facilitates rapid Li surface diffusivity, while the PdTe 2 and NiTe 2 coatings provide shorter diffusion paths for Li adatoms on the CCs and LMAs. In addition, Li 2 Te, formed as a byproduct of the decomposition of PdTe 2 and NiTe 2 during Li plating, reduces the critical nucleus size by minimizing the interfacial energy between the electrolyte and the plated Li. PtTe 2 more effectively enhances the AFLB cycling performance, whereas PdTe 2 and NiTe 2 are more advantageous for LMBs. Notably, a 5‐nm‐thick PdTe 2 coating on the LMA achieves 80% capacity retention after 450 cycles using a LiFePO 4 cathode (3 mAh cm −2 ) at a 0.5 C‐rate.