The stability issue of LiCoO2 cycled at high voltages is one of the burning questions for the development of lithium ion batteries with high energy density and long cycling life. Although it is effective to improve the cycling performance of LiCoO2 via coating individual LiCoO2 particles with another metal oxides or fluorides, the rate capacity is generally compromised because the typical coating materials are poor conductors. Herein, amorphous Li0.33La0.56TiO3, one of the most successful solid electrolytes, was directly deposited on the surface of made-up LiCoO2 electrodes through magnetron sputtering. Not only the inherent conductive network in the made-up LiCoO2 electrodes was retained, but also the Li+ transport in bulk and across the cathode-electrolyte interface was enhanced. In addition, the surface chemical analysis of the cycled LiCoO2 electrodes suggests that most of the stability issues can be addressed via the deposition of amorphous Li0.33La0.56TiO3. With an optimized deposition time, the LiCoO2 electrodes modified by Li0.33La0.56TiO3 performed a steady reversible capacity of 150 mAh/g at 0.2 C with the cutoff voltage from 2.75 to 4.5 V vs. Li+/Li and an 84.6% capacity gain at 5 C comparing with the pristine one.

中文翻译：

---

通过导电非晶 LLTO 薄膜对电极进行表面改性，提高了 LiCoO2 在 4.5 V 下的循环稳定性。


LiCoO2在高电压下循环的稳定性问题是开发高能量密度和长循环寿命的锂离子电池的紧迫问题之一。虽然通过用另一种金属氧化物或氟化物涂覆单个LiCoO2颗粒可以有效提高LiCoO2的循环性能，但由于典型的涂层材料是不良导体，倍率容量通常会受到影响。在此，通过磁控溅射将最成功的固体电解质之一非晶态 Li0.33La0.56TiO3 直接沉积在制成的 LiCoO2 电极的表面上。不仅保留了制成的 LiCoO2 电极中固有的导电网络，而且还增强了 Li+ 的本体传输和跨阴极-电解质界面的传输。此外，循环 LiCoO2 电极的表面化学分析表明，大多数稳定性问题可以通过沉积非晶态 Li0.33La0.56TiO3 来解决。通过优化沉积时间，Li0.33La0.56TiO3 修饰的 LiCoO2 电极在 0.2 C 下表现出 150 mAh/g 的稳定可逆容量，截止电压相对于 Li+/Li 为 2.75 至 4.5 V，在与原始的相比5°C。