This paper presents cycle aging results of a commercial lithium-ion cell from a comprehensive, 29 month aging study and follows up on calendar aging results published previously [1]. We use a widely used commercial ${\text{LiFePO}}_4$/graphite cell from Sony/Murata, which promises long calendar and cycle lifetime, that would make it suitable for stationary battery applications. The evolution of the cells’ capacity and impedance are shown in a static cycle aging study for 19 test points with different combinations of temperature, C-rate, depth of discharge and state of charge. Based on the measurement data shown herein and the calendar aging model presented in the previous paper, a semi-empirical combined aging model is presented for the capacity loss and resistance increase. Two dynamic load profiles are used to experimentally validate the combined aging model. Absolute model errors below 1% for the capacity loss and below 2% for the resistance increase in both dynamic load profiles demonstrate that the combined aging model can predict the lifetime of ${\text{LiFePO}}_4$/graphite battery cells for different applications and varying operation conditions adequately. In the cycle experiments, an unexpectedly strong, but partly reversible capacity loss is observed with shallow cycles at medium states of charge.

本文通过全面的29个月老化研究展示了商用锂离子电池的循环老化结果，并对先前发表的日历老化结果进行了跟踪[1]。我们使用广泛使用的商业广告${\text{磷酸铁锂}}_4$索尼/村田制作所的/石墨电池，它具有较长的日历和循环寿命，因此非常适合固定电池应用。在静态循环老化研究中，针对19个测试点显示了电池容量和阻抗的变化，这些测试点具有温度，C速率，放电深度和充电状态的不同组合。基于此处显示的测量数据和先前论文中提出的日历老化模型，提出了一种用于容量损失和电阻增加的半经验组合老化模型。两个动态负载曲线用于通过实验验证组合的老化模型。在两个动态负载曲线中，对于容量损失而言，绝对模型误差均低于1％，对于电阻增加而言，其绝对模型误差低于2％，这表明组合的老化模型可以预测电池的寿命${\text{磷酸铁锂}}_4$/石墨电池，适合不同的应用场合和变化的运行条件。在循环实验中，在中等荷电状态下，浅循环会观察到出乎意料的强但部分可逆的容量损失。