A Robust Li ⁺ ‐Rich Protective Layer for High‐Performance Dendrite‐Free Li Metal Batteries

Abstract Essentially, rapid Li ⁺ accumulation in the anode region triggers a strong space charge layer and significant Li ⁺ concentration gradient, which ultimately leads to Li dendrites and interface issues. Herein, a mechanically robust layer consisting of lithiated‐palygorskite (Li‐Pal) and thermoplastic polyurethane elastomer (TPU) is employed to regulate the Li electrochemistry. The negatively charged Li‐Pal surface demonstrates an exceptional lithiopholicity, which can leverage Li ⁺ supplement function to mitigate the concentration gradient. Meanwhile, the high elasticity of TPU can suppress Li dendrite growth and penetration during cycling. Enabled by such a hybrid layer, a high Coulombic efficiency (CE) of 99.1% over 300 cycles is delivered in Li/Cu half cells, and a long cycling life over 1400 h is achieved in a symmetric cell. The corresponding LiFePO ₄ full cells present a high capacity retention of 90.6% over 1000 cycles at 5 C. This interfacial engineering highlights the synergetic design of a protective layer with high mechanical stability and Li ⁺ affinity for dendrite‐free Li metal batteries.