High-voltage plastic solid electrolytes (PSEs) have emerged as appealing candidates for energy-dense Li-metal batteries, but their inherent instabilities toward reductive Li anodes pose a hurdle to practical application. Herein, we report the monoanion-regulated design of a lithium-inert, high-voltage PSEs, demonstrated with a nitrile-decorative PSEs (CN-PSEs) driven by BF₂C₂O₄⁻ monoanion. The monoanion-induced shielding layer helps to smooth lithium deposition, suppress the plastic matrix depletion, and thus retain robust Li/CN-PSEs interface even after cycling up to 1600 h in Li/Li cell, while the high-polarity nitrile group can support ion conduction and high-voltage tolerance up to 5.25 V. Benefit from the synergy, all-solid-state batteries with CN-PSEs show the superior cycling (300 cycles at 25 °C). This effective strategy provides a novel design principle for high-voltage PSEs to address the poor reductive stability.

高压塑料固体电解质（PSE）已成为能量密集型锂金属电池的有吸引力的候选材料，但它们对还原性锂阳极固有的不稳定性给实际应用带来了障碍。在本文中，我们报道了锂惰性的单价阴离子调节的设计，高电压的PSE，与由驱动腈装饰的PSE（CN的PSE）证明BF ₂ c ^ ₂ Ò ₄ ^-单阴离子。单阴离子诱导的屏蔽层有助于平滑锂的沉积，抑制塑料基质的消耗，从而即使在Li / Li电池中循环长达1600 h后仍能保持稳健的Li / CN-PSEs界面，而高极性腈基可以支持离子传导和高达5.25 V的高压耐受性。得益于协同作用，具有CN-PSE的全固态电池具有出色的循环性能（在25°C时可循环300次）。这种有效的策略为高压PSE提供了新颖的设计原理，以解决不良的还原稳定性。