Critical review and analysis of available capacity estimation of LiFePO ₄ battery using Peukert's law: A case study

Abstract

Summary Internal state estimation of lithium‐ion batteries (LIBs) is the core function of the battery management system (BMS) of electric vehicles (EVs). State of charge, state of health, and state of energy are all related to the capacity of LIBs. The original Peukert's law was proposed for the available capacity estimation of lead‐acid batteries at a constant current, in which the effects of temperature and variable current are not considered. Thus, it only works in ideal environments, and far from the working environment of electric vehicle power batteries. In this paper, the applied research and future challenges of Peukert's law are reviewed and summarized, and then available capacity modeling of LIBs is achieved based on improved Peukert's law considering temperature and variable current, respectively. As a case study of lithium‐ion battery for vehicle, a module with 20 battery cells in parallel was tested and analyzed under different conditions in the MKLtech battery test system (BTS). The experimental results show that the maximum error of the proposed method is less than 2.81% under different conditions. More importantly, the simple parameter identification and high computational efficiency of the proposed model are integral to the application in the BMSs of EVs.

Organic photo-battery with high operating voltage using a multi-junction organic solar cell and an organic redox-polymer-based battery

“…It is apparent, that the discharge capacities achieved with this initial charging protocol are much below the theoretical specific capacity of the P(PT-T2) composite electrode of 36.5 mAh g −1 . This incomplete charge is mostly related to the protocol itself which cuts the charge after few seconds because the voltage limit is rapidly reached with the charging photocurrents delivered at 1 sun, and partially due to kinetic limitations, which are described by Peukert's law, 68 and they are especially effective at these high charge rates.…”