Garnet electrolyte-based lithium (Li) metal batteries, which employ garnet-type Li₇La₃Zr₂O₁₂ (LLZO) as electrolyte and Li metal as anode, are regarded as a promising candidate for high-energy batteries. However, Li dendrites formation as well as poor solid-solid contact between the electrolyte and electrodes result in high interfacial resistance, large polarizations, and low Coulombic efficiency. Herein, we demonstrated that solid polymer electrolyte (SPE) soft interface layer deposited on garnet electrolyte (Ta-doped LLZO (LLZTO)) surface along with 3D Li metal anode can address these obstacles. In this architecture, SPE layer was deposited on garnet electrolyte surface to endow connected interface between the electrolyte and electrodes and thus settled the interface contact issue. 3D Li metal anode can accomplish dendrite-suppression by increasing Li ions deposition sites to lower the effective current density and render a uniform Li nucleation with 3D frameworks. With this ingenious arrangement, the solid-state 3D Li︱SPE-LLZTO-SPE︱3D Li symmetrical cell exhibits a stable voltage profile over 700 h and solid-state LiFePO₄︱SPE-LLZTO-SPE︱3D Li full cell also shows an extremely superior cyclability and high Coulombic efficiency even at 90 °C. This work provides an alternative option for manufacturing safe and stable solid-state Li metal batteries.

使用石榴石型Li ₇ La ₃ Zr ₂ O _12的石榴石电解质基锂（Li）金属电池（LLZO）作为电解质，锂金属作为阳极，被认为是高能电池的有希望的候选者。然而，Li树枝状晶体的形成以及电解质和电极之间不良的固-固接触导致高的界面电阻，大的极化和低的库仑效率。本文中，我们证明了沉积在石榴石电解质（Ta掺杂的LLZO（LLZTO））表面上的固体聚合物电解质（SPE）软界面层以及3D Li金属阳极可以解决这些障碍。在这种体系结构中，SPE层沉积在石榴石电解质表面上，赋予电解质和电极之间的连接界面，从而解决了界面接触问题。3D锂金属阳极可通过增加锂离子沉积位点以降低有效电流密度并通过3D框架实现均匀的锂成核来实现枝晶抑制。通过这种巧妙的安排，固态3DLi︱SPE-LLZTO-SPE︱3DLi对称电池在700小时内表现出稳定的电压分布，并且固态LiFePO₄ ︱SPE-LLZTO-SPE︱3D李全电池还示出了极其优异的循环性能和高的库仑效率，即使在90℃。这项工作为制造安全稳定的固态锂金属电池提供了另一种选择。