Lithium-titanate-oxide (LTO) batteries are one of the most promising technologies for various types of future applications in electric mobility, stationary storage systems and hybrid applications with high-power demands due to their long cyclic stability and superior safety. In our prior investigation we tested the cyclic and calendar ageing of 43 LTO cells under 16 different operation conditions and analysed the results using an incremental capacity analysis (ICA).
In this poster, we will focus on the different ageing mechanisms occuring within LTO based batteries. For instance, the cells exhibit a multi-stage ageing mechanism with stagewise increasing degradation gradient. In the first ageing stage the LTO anode limits the amount of extractable capacity. After a certain amount of cathode degradation is reached an inflexion point occurs and the cathode starts limiting the amount of extractable capacity and thus determine the ageing gradient. This initiates the second ageing stage with much stronger occuring capacity fading gradient. Additionally, some cells experience a reversible increase in extractable capacity before any degradation becomes visible. Hence, for these cells an initial capacity gain stage becomes apparent.