Highly Stable Lithium Metal Anode with Near-Zero Volume Change Enabled by Capped 3D Lithophilic Framework

Abstract Uncontrolled dendrite growth, infinite volume-change and unstable solid-electrolyte interface in lithium metal anode have seriously hampered the further applications of Li-based batteries. Despite considerable efforts, challenges still remain in obtaining dendrite-free lithium metal anode with low volume change, especially at high current density with high areal capacity. Herein, we firstly design and fabricate a capped 3D framework, comprising a lithiphilic matrix with polyacrylic acid (PAA) coating, to construct stable artificial SEI on 3D high-lithium-reservoir host. In this way, the in-situ formed high-ion conductive LiPAA can facilitate Li+ transfer inside the skeleton rather than depositing on the surface, leading to dendrite-free lithium anode. Based on the rational structure design, PAA@Li matrix exhibits near-zero volume change upon the cycling, which is tracked by in-situ swelling tester. Therefore, PAA@Li matrix undoubtedly demonstrates enhanced battery performance with excellent cycling stability for 350 h at both high areal capacity (5 mAh/cm2) and high current density (5 mA/cm2). The corresponding LiCoO2|PAA@Li matrix full cell also presents improved long-term stability of 81% retention after 1000 cycles. The novel capped 3D framework may open up a new horizon to achieve highly stable lithium anode with zero volume change.