Solid-state lithium metal batteries are one of the most promising options for next-generation batteries pursuing high-energy density and high-safety. However, the inevitable volatilization of lithium compounds during sintering leads to low relative density and low ionic conductivity of solid-state electrolytes. Herein, the dynamic lithium-compensation mechanism is proposed to facilitate the densification of Ta-substituted garnet-type electrolyte (Li_6.5La₃Zr_1.5Ta_0.5O₁₂ (LLZT)) through the reversible manipulating of Li₂O atmosphere. Li₂ZrO₃ is used as mother powder additive, which reacts with Li₂O in sintering atmosphere and forms Li₆Zr₂O₇. Li₂ZrO₃/Li₆Zr₂O₇ buffer pair manipulates the sintering Li₂O atmosphere, which is vital for LLZT, within the Li₂O partial pressure range corresponding to Li₂ZrO₃ and Li₆Zr₂O₇. Furthermore, the reversibility mechanism of buffer pair for Li₂O absorption and release is revealed. The obtained LLZT exhibits a relative density of over 96% and an ionic conductivity exceeding 7 × 10⁻⁴ S·cm⁻¹ with no abnormal grain growth. The symmetric cell demonstrates an excellent lithium dendrite suppressing ability (stable cycling at a current density of 0.3 mA·cm⁻² for over 1000 h). Such dynamic lithium-compensation strategy has been successfully applied in atmosphere manipulation of LLZT sintering process, which reduces the dependence of LLZT on the Li₂O atmosphere, making it conducive to large-scale preparation of electrolyte ceramics.

固态锂金属电池是追求高能量密度和高安全性的下一代电池最有前途的选择之一。然而，烧结过程中不可避免的锂化合物挥发导致固态电解质的相对密度低和离子电导率低。在此，提出了动态锂补偿机制，通过对Li ₂ O气氛的可逆控制来促进Ta取代石榴石型电解质（Li _6.5 La ₃ Zr _1.5 Ta _0.5 O ₁₂ (LLZT)）的致密化。以Li ₂ ZrO ₃为母粉添加剂，在烧结气氛中与Li _{2 O反应生成Li 6} Zr ₂ O ₇。 Li ₂ ZrO ₃ /Li ₆ Zr ₂ O ₇缓冲剂对在对应于Li ₂ ZrO ₃和Li ₆ Zr ₂ O _{7的Li 2} O分压范围内操纵对于LLZT至关重要的烧结Li ₂ O气氛。此外，还揭示了缓冲液对对Li ₂ O吸收和释放的可逆性机制。所得LLZT的相对密度超过96％，离子电导率超过7×10 ^-4 S·cm ^-1，且没有异常晶粒生长。该对称电池表现出优异的锂枝晶抑制能力（在0.3 mA·cm ^-2的电流密度下稳定循环超过1000小时）。这种动态锂补偿策略已成功应用于LLZT烧结过程的气氛控制中，减少了LLZT对Li ₂ O气氛的依赖，有利于电解质陶瓷的大规模制备。