(1. 吳江出入境檢驗檢疫局，吳江 215200；2. 江蘇大學(xué) 材料科學(xué)與工程學(xué)院，鎮(zhèn)江 212013；
3. 中南大學(xué) 冶金科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 采用商品化的LiMn2O4制作錳酸鋰/石墨電池，研究其儲存性能，并對儲存前后的正極、負極和電解液進行表征分析。結(jié)果表明：半荷電常溫儲存一個月，電池容量衰減3.7%，循環(huán)性能得到改善。X射線衍射和透射電鏡結(jié)果表明：LiMn2O4晶格發(fā)生收縮，正極表面形成一層固體電解質(zhì)(SEI)膜。交流阻抗研究表明：正極阻抗由儲存前的62.69 Ω增大到儲存后的84.64 Ω，負極阻抗由儲存前的183.1 Ω增大到儲存后的301 Ω。紅外光譜分析表明：電解液溶劑和電解質(zhì)鹽均不同程度地發(fā)生了分解，錳酸鋰電池儲存后容量衰減主要是由電極極化、Mn溶解、電解液分解、負極SEI膜增厚等原因造成。
關(guān)鍵字: 錳酸鋰電池；儲存；容量衰減；機理
（1. Wujiang Entry-Exit Inspection and Quarantine Bureau, Wujiang 215200, China;
2. School of Material Science and Engineering, Jiangsu University, Zhenjiang 212013, China;
3. School of Metallurgical Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The power battery was manufactured with the commercial LiMn2O4 and graphite. The storage performance of LiMn2O4 battery was tested. The cathode, anode and electrolyte before and after storage were characterized. The result shows that the capacity fading ratio of LiMn2O4 battery at half-charged state is 3.7%, but the cycling performance is improved after storage. XRD results show that the crystal lattice of LiMn2O4 shrinks. TEM results show that the surface of LiMn2O4 particles is covered with SEI film. The cathode impedance increases from 62.69 Ω to 84.64 Ω and that of anode increases from 183.1 Ω to 301 Ω. FT-IR results show that the solvent and solutes of electrolyte decompose at a certain degree after storage. The polarization, Mn dissolution, electrolyte decomposition and the incrassation of anode SEI are responsible for the capacity fading of LiMn2O4 battery after storage.
Key words: LiMn2O4 battery; storage; capacity fading; mechanism
