固定二次应用场景下基于LCA的动力电池退役点定量确定方法

Quantitative method to determine retiring point of batteries for electric vehicles based on LCA under fixed second-use scenarios

退役动力电池的梯次利用不仅可降低电池的使用成本,还可缓解回收退役电池的环境污染压力。为了定量确定动力电池退役点,本文提出了一种基于生命周期分析(LCA)定量分析方法。将动力电池梯次利用的生命周期划分为生产、作动力电池、重组、作储能电池和回收利用5个阶段,将电池的容量衰退与生命周期分析模型结合,在不同的二次应用场景下分析了电池的碳排放量随动力电池退役时的健康状态(SOH)变化情况,研究了退役点选择对电池寿命和环境的影响。研究表明,动力电池在SOH为85%～90%时退役可达到较小的碳排放量。在固定二次应用场景下,电池操作的放电深度(DOD)越小,则电池寿命越长,且碳排放量变化很小。研究为动力电池退役点的确定提供了定量分析方法,可为动力电池梯次利用提供指导。

Reusing the retired batteries in stationary applications can not only reduce the cost of batteries for electric vehicles(EV) but also ease the environment pollution pressure. To quantitatively determine the retiring point of batteries for the EV, a quantitative method based on the Life Cycle Assessment(LCA) was proposed in this paper. The life cycle of the reused battery was divided into 5 processes, including manufacturing, using in EV, re-manufacturing, reusing in stationary applications,and recycling phases. The LCA model was combined with the capacity degradation model and the changes in battery’s carbon emission as the state of health(SOH) of retiring point changed under different second-use scenarios. The study showed that when the SOH of 85%-90% was adopted, a lower carbon emission of battery in its whole life could be achieved. In addition, for a given stationary application scenario, the battery’s life was lengthened and the carbon emissions changed slightly as the depth of discharge(DOD) decreases. This paper is expected to provide a quantitative analysis method for determining the retiring point of batteries for EV.