Mechanism of Capacity fading caused by Mn(Ⅱ) deposition on anodes of spinel lithium manganese oxide

• 作 者: Haihui Chen Xinping Qiu
• 机 构: College of Chemistry & Chemical Engineering,JingGangSshan University,Ji'An,Jiangxi,China;Department
• 出 处: 中国化学会2014年中西部地区无机化学化工学术研讨会
• 发表日期: 2014年5期

The capacity fading of spinel lithium manganese oxide cell is a bottleneck question of large-scale application.The traditional opinion thinks that Mn(Ⅱ) ions at the anode is reduced to metal manganese,which catalyzes electrolyte decomposition,poisons and hurts the solid electrolyte interface (SEI) film,then results in lithium ion batteries capacity fading.But our research team first identified the oxide manganese deposited on the anode is +2 valent,and has not been reduced to metallic manganese.Based on the new discovery "manganese oxides deposited on anode is +2 valent",the following issues are discussed:deposition mechanism of Mn (Ⅱ) how to reach the (graphite) anode surface SEI film;Mn (Ⅱ) in the anode SEI how to affect the batteries capacity fading.The new mechanism is firstly proposed that "Mn (Ⅱ) is exchanged with active lithium ions in the anode SEI films,then deposited on the anodes,which hinders,or blocks the intercalation (de-intercalation)of lithium ions,then results in cell capacity fading".