Poly (ethylene oxide) based solid polymer electrolytes are suitable candidates for constructing all-solid-state lithium metal batteries. However, the low ionic conductivities, poor mechanical strength and incompetence to suppress the penetration of Li dendrites hinder their practical application. Herein, we introduce Zinc bis(2-ethylhexanoate) (Zn (BEH)₂) as a homogeneous and bifunctional additive into PEO network by a simple solution casting method to achieve improvements of ionic conductivity and uniformity of lithium deposition. It is shown that the Lewis acid–base interactions between Zn (BEH)₂ and PEO chains suppress the polymer crystallization and weaken the O–Li⁺ interaction, resulting in a good ionic conductivity of 1.1 × 10⁻⁵ S cm⁻¹ at 30 °C, 2.7 × 10⁻⁴ S cm⁻¹ at 60 °C and an improved lithium ion transfer number of 0.5 at 60 °C. Furthermore, a LiZn alloy layer is formed in-situ on lithium metal anode via the reaction between Zn (BEH)₂ and Li, which effectively prevents dendrite growth. Based on PEO–Zn (BEH)₂ polymer electrolyte, a Li/Li symmetric cell exhibits a steady cycling over 500 h with a low polarization potential of 150 mV. This strategy will illuminate new design strategy to advance polymer electrolytes towards high performance solid-state lithium batteries.

聚（环氧乙烷）基固体聚合物电解质是构建全固态锂金属电池的合适候选物。然而，低的离子电导率，差的机械强度和抑制锂树枝状晶体渗透的能力不足阻碍了它们的实际应用。在这里，我们通过一种简单的溶液浇铸方法将双（2-乙基己酸）锌（Zn（BEH）₂）作为均相和双功能添加剂引入PEO网络中，以提高离子电导率和锂沉积的均匀性。结果表明，Zn（BEH）₂和PEO链之间的路易斯酸碱相互作用抑制了聚合物的结晶并削弱了O-Li ^+的相互作用，从而产生了1.1×10 ^-5的良好离子电导率。 小号厘米^-1  ，在30℃，2.7×10 ^-4 小号厘米^-1  ，在60℃和0.5，在60的改进的锂离子迁移数℃。此外，通过Zn（BEH）₂和Li之间的反应在锂金属阳极上原位形成LiZn合金层，这有效地防止了枝晶生长。基于PEO-Zn（BEH）₂聚合物电解质，Li / Li对称电池在500小时内表现出稳定的循环，极化电位低至150 mV。该策略将阐明新的设计策略，以使聚合物电解质朝着高性能固态锂电池发展。