Siller Valerie, Gonzalez-Rosillo Juan Carlos, Eroles Marc Nuñez, Baiutti Federico, Liedke Maciej Oskar, Butterling Maik, Attallah Ahmed G, Hirschmann Eric, Wagner Andreas, Morata Alex, Tarancón Albert
Catalonia Institute for Energy Research (IREC), Jardins de les Dones de Negre 1, Planta 2, Sant Adrià del Besòs, Barcelona 08930, Spain.
Helmholtz-Zentrum Dresden─Rossendorf, Institute of Radiation Physics, Bautzner Landstraße 400, Dresden 01328, Germany.
ACS Appl Mater Interfaces. 2022 Jul 13;14(29):33438-46. doi: 10.1021/acsami.2c10798.
Extending the potential window toward the 3 V plateau below the typically used range could boost the effective capacity of LiMnO spinel cathodes. This usually leads to an "overdischarge" of the cathode, which can cause severe material damage due to manganese dissolution into the electrolyte and a critical volume expansion (induced by Jahn-Teller distortions). As those factors determine the stability and cycling lifetime for all-solid-state batteries, the operational window of LiMnO is usually limited to 3.5-4.5 V versus Li/Li in common battery cells. However, it has been reported that nano-shaped particles and thin films can potentially mitigate these detrimental effects. We demonstrate here that porous LiMnO thin-film cathodes with a certain level of off-stoichiometry show improved cycling stability for the extended cycling range of 2.0-4.5 V versus Li/Li. We argue through spectroscopic ellipsometry that the origin of this stability lies in the surprisingly small volume change in the layer during lithiation.
将电势窗口扩展至低于通常使用范围的3V平台，可以提高LiMnO尖晶石阴极的有效容量。这通常会导致阴极“过放电”，由于锰溶解到电解质中以及临界体积膨胀（由 Jahn-Teller 畸变引起），这可能会造成严重的材料损坏。由于这些因素决定了全固态电池的稳定性和循环寿命，在普通电池中，LiMnO的工作窗口通常限制在相对于Li/Li为3.5 - 4.5V。然而，据报道，纳米形状的颗粒和薄膜可能会减轻这些有害影响。我们在此证明，具有一定非化学计量比水平的多孔LiMnO薄膜阴极在相对于Li/Li为2.0 - 4.5V的扩展循环范围内显示出改善的循环稳定性。我们通过光谱椭偏法认为，这种稳定性的根源在于锂化过程中该层中令人惊讶的小体积变化。
