Tyndall National Institute, Lee Maltings, University College Cork, T12 R5CP Cork, Ireland.
Int J Mol Sci. 2023 Jul 7;24(13):11207. doi: 10.3390/ijms241311207.
This work shows the electrochemical performance of sputter-deposited, binder-free lithium cobalt oxide thin films with an alumina coating deposited via atomic layer deposition for use in lithium-metal-based microbatteries. The AlO coating can improve the charge-discharge kinetics and suppress the phase transition that occurs at higher potential limits where the crystalline structure of the lithium cobalt oxide is damaged due to the formation of Co, causing irreversible capacity loss. The electrochemical performance of the thin film is analysed by imposing 4.2, 4.4 and 4.5 V upper potential limits, which deliver improved performances for 3 nm of AlO, while also highlighting evidence of Al doping. AlO-coated lithium cobalt oxide of 3 nm is cycled at 147 µA cm (~2.7 C) to an upper potential limit of 4.4 V with an initial capacity of 132 mAh g (65.7 µAh cm µm) and a capacity retention of 87% and 70% at cycle 100 and 400, respectively. This shows the high-rate capability and cycling benefits of a 3 nm AlO coating.
这项工作展示了通过原子层沉积（ALD）沉积氧化铝涂层的溅射沉积无粘结剂锂钴氧化物薄膜的电化学性能，该薄膜可用于基于锂金属的微电池。AlO 涂层可以改善充放电动力学，并抑制在更高的电位极限下发生的相变，在更高的电位极限下，由于形成 Co，锂钴氧化物的晶体结构被破坏，导致不可逆容量损失。通过施加 4.2、4.4 和 4.5 V 的上限电位来分析薄膜的电化学性能，3nm 的 AlO 可提高性能，同时也证明了 Al 的掺杂。3nm 的 AlO 涂层的锂钴氧化物在 147µA cm（约 2.7C）下循环至 4.4V 的上限电位，初始容量为 132mAh g（65.7µAh cm µm），在第 100 和 400 次循环时的容量保持率分别为 87%和 70%。这表明 3nm AlO 涂层具有高倍率性能和循环优势。
