Critical review of non-invasive diagnosis techniques for quantification of degradation modes in lithium-ion batteries

Understanding the root causes of Lithium-ion battery degradation is a challenging task due to the complexity of the different mechanisms involved. For simplicity, ageing mechanisms are often grouped into three degradation modes (DMs): conductivity loss, loss of active material and loss of lithium inventory. Battery Management Systems (BMSs) do not currently include an indication of the underlying DMs causing the degradation. Pseudo Open Circuit Voltage (pOCV), Incremental Capacity - Differential Voltage (IC-DV), Electrochemical Impedance Spectroscopy and Differential Thermal Voltammetry are the most common non-invasive diagnosis techniques studied in the literature to quantify DMs. This work presents a critical and systematic review of these techniques with the focus on the elaboration of their strengths and weaknesses for the implementation in automotive applications. Firstly, each technique is classified into different groups and their working principles are presented. Secondly, an evaluation criterion is introduced to review each technique following a systematic approach. The comparison of the techniques highlight that pOCV and IC-DV are the most advantageous because they fulfill most of the points included in the evaluation criteria. The further implementation of these techniques would support battery lifetime control strategies and battery designs.