Solid-state battery with lithium anode and NASICON-type electrolyte, particularly.Li_1+xAl_xGe_2-x(PO₄)₃ (LAGP), is promising safety rechargeable energy source. However, the Li|LAGP system exhibits a rapid decline in performance and a limited operational lifespan. One potential avenue for enhancing operational lifespan is the introduction of functional nanocoating at the anode/electrolyte interface. The present study considers the La-Al-O at varying Al:La ratios obtained by atomic layer deposition (ALD) as the functional coating, where Al-O was used to increase the interface stability and La-O to vary conductivity and electrochemical stability of the coating. It was shown that mixed oxide LaAlO₃–Al₂O₃ (La_xAl_2-xO₃, x < 1) is formed at low La contents, which lead to stable operation without increasing overvoltage for more than 1000 h. Moreover, the introduction of 1 at% La results in an interface resistance decrease compared to Al₂O₃ coating and uncoated LAGP. It was also shown that high La content decreases the initial interface resistance, but affects the composition uniformity due to the lanthanum carbonate appearance, which leads to LAGP degradation at currents greater than 0.2 mA/cm². Therefore, it is possible to extend the cycling life and stability of the LAGP solid electrolyte in contact with lithium by introducing a LaAlO₃–Al₂O₃ functional coating.

中文翻译：

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La-Al-O 功能纳米涂层提高固态电池中 Li1+xAlxGe2-x（PO4）3/Li 金属界面的稳定性


特别是具有锂负极和 NASICON 型电解质的固态电池。Li_1+xAl_xGe_2-x（PO₄）₃ （LAGP） 是很有前途的安全可充电能源。然而，Li|LAGP 系统的性能迅速下降，使用寿命有限。提高使用寿命的一种潜在途径是在阳极/电解质界面引入功能性纳米涂层。本研究将原子层沉积 （ALD） 获得的不同 Al：La 比率的 La-Al-O 视为功能涂层，其中 Al-O 用于增加界面稳定性，La-O 用于改变涂层的电导率和电化学稳定性。结果表明，在低 La 含量下形成混合氧化物 LaAlO_{3-Al 2}O₃ （La_xAl_2-xO₃， x < 1），这导致稳定运行，无需增加过电压超过 1000 小时。此外，与 Al₂O₃ 涂层和未涂层的 LAGP 相比，引入 1 at% La 会导致界面电阻降低。研究还表明，高 La 含量会降低初始界面电阻，但由于碳酸镧的外观会影响成分均匀性，这会导致在大于 0.2 mA/cm² 的电流下 LAGP 降解。因此，通过引入 LaAlO_{3-Al 2}O₃ 功能涂层，可以延长 LAGP 固体电解质与锂接触时的循环寿命和稳定性。