A Novel Experimental Technique for Use in Fast Parameterisation of Equivalent Circuit Models for Lithium-Ion Batteries

Abstract

Battery models are one of the most important tools for understanding the behaviour of batteries. This is particularly important for the fast-moving electrical vehicle industry, where new battery chemistries are continually being developed. The main limiting factor on how fast battery models can be developed is the experimental technique used for collection of data required for model parametrisation. Currently, this is a very time-consuming process. In this paper, a fast novel parametrisation testing technique is presented. A model is then parametrised using this testing technique and compared to a model parametrised using current common testing techniques. This comparison is conducted using a WLTP (worldwide harmonised light vehicle test procedure) drive cycle. As part of the validation, the experiments were conducted at different temperatures and repeated using two different temperature control methods: climate chamber and a Peltier element temperature control method. The new technique introduced in this paper, named AMPP (accelerated model parametrisation procedure), is as good as GITT (galvanostatic intermittent titration technique) for parametrisation of ECMs (equivalent circuit models); however, it is 90% faster. When using experimental data from a climate chamber, a model parametrised using GITT was marginally better than AMPP; however, when using experimental data using conductive control, such as the ICP (isothermal control platform), a model parametrised using AMPP performed as well as GITT at 25 °C and better than GITT at 10 °C.

Advancing state estimation for lithium-ion batteries with hysteresis: systematic extended Kalman filter tuning

“…Initially, Thévenin ECM parameters are fitted to GITT data using ordinary least squares. Time constants τ 1 = 2 and τ 2 = 50 are chosen based on previous works [12,32]. Parameters of each GITT pulse are used to populate a lookup table (LUT), with linear interpolation used between breakpoints.…”

Testing and Characterizing Commercial 18650 Lithium-Ion Batteries

“…Impulsive current charge/discharge tests are commonly presented in literature to determine the ECM parameters of lithium-ion batteries [10,12,30]. Such impulsive test take different names, e.g.…”

Large scale immersion bath for isothermal testing of lithium-ion cells

“…The state of the industry means that there is an enormous amount of battery testing being conducted across the world, in what are most often referred to as cell ‘characterisation’ experiments [6] , [7] . Characterisation experiments enable engineers to understand and optimise the use of their chosen cell [8] , [9] , [10] , [31] .…”