Recently developed electrochemical lithium recovery systems, whose operation principle mimics that of lithium-ion battery, enable selective recovery of lithium from source waters with a wide range of lithium ions (Li⁺) concentrations; however, physicochemical behaviors of the key component—Li⁺-selective electrode—in realistic operation conditions have been poorly understood. Herein, we report an investigation on a λ-MnO₂ electrode during the electrochemical lithium recovery process with regards to the Li⁺ concentration in source water and operation rate of the system. Three distinctive stages of λ-MnO₂ originating from different limiting factors for lithium recovery are defined with regard to the rate of Li⁺ supply from the electrolyte: depleted, transition, and saturated regions. By characterization of λ-MnO₂ at different stages using diverse X-ray techniques, the importance of Li⁺ concentration in the vicinity of the electrode surface is revealed. On the basis of this understanding, increasing the density of the electrode/electrolyte interface is suggested as a realistic and general route to enhance the overall lithium recovery performance and is experimentally corroborated at a wide range of operation environments.

中文翻译：

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了解λ-MnO2在电化学锂回收中的行为：关键限制因素和增强性能的途径。

最近开发的电化学锂回收系统，其操作原理模拟物中的锂离子电池的，使得能够从具有广泛的锂离子（Li源水域锂的选择性回收⁺）的浓度; 然而，人们对关键成分Li ⁺ -选择电极在实际操作条件下的物理化学行为了解甚少。在本文中，我们报道了在λ-MnO的调查₂与关于锂在电化学锂恢复过程中电极⁺在源水和系统的运转率的浓度。λ-MnO的的三个不同阶段₂从不同的限制因素锂回收始发与关于Li的速率定义⁺来自电解质的电源：耗尽，过渡和饱和区域。通过λ-MnO的表征₂在使用不同的X射线技术不同的阶段，Li的重要性⁺在电极表面附近浓度被揭示。基于该理解，建议增加电极/电解质界面的密度是提高总体锂回收性能的现实且通用的途径，并且在广泛的操作环境中通过实验得到证实。