Atomic Zn Embedded Subnanopore‐Rich Hard Carbon Fibers Toward Highly Reversible Quasi‐Metallic Li/Na Storage

ABSTRACT The practical applications of Li metal anode and Na metal anode are limited by uncontrollable Li/Na dendrite growth and low Coulombic efficiency (CE). Specifically, highly active metallic Li/Na and sluggish desolvation step are the main incentives for serious side reactions. Herein, we propose atomic Zn embedded subnanopore‐rich hard carbon fibers with soft‐carbon coating (Zn/CF@SC) to solve the above issues. Benefitting from the confinement effect of subnanopores and the catalytic function of Zn single atoms, the Zn/CF@SC can effectively promote the desolvation of solvated‐Li ⁺ /Na ⁺ , leading to suppressed side reactions. As expected, the Li||Zn/CF@SC and Na||Zn/CF@SC half cells demonstrate long lifespans over 450 cycles and 200 cycles with high CE over 99%. Moreover, the Zn/CF@SC||LiNi _0.8 Co _0.1 Mn _0.1 O ₂ and Zn/CF@SC||Na ₃ V ₂ (PO ₄ ) ₃ pouch cells exhibit stable performance over 700 and 400 cycles with good capacity retentions of about 80%.