Electrothermal impedance spectroscopy as a cost efficient method for determining thermal parameters of lithium ion batteries: Prospects, measurement methods and the state of knowledge Maciej Swierczynski * , Daniel Ioan Stroe, Tiberiu Stanciu, Søren Knudsen Kær Aalborg University, Department of Energy Technology, Pontoppidanstræde 111, 9220 Aalborg, Denmark article info Article history: Received 9 February 2016 Received in revised form 14 September 2016 Accepted 14 September 2016 Available online xxx Keywords: Lithium-ion battery Electrothermal impedance spectroscopy Battery thermal model Thermal impedance abstract Current lithium-ion battery research aims in not only increasing their energy density but also power density. Emerging applications of lithium-ion batteries (hybrid electric vehicles, plug-in hybrid electric vehicles, grid support) are becoming more and more power demanding. The increasing charging and discharging power capability rates of lithium-ion batteries raises safety concerns and requires thermal management of the entire battery system. Moreover, lithium-ion battery's temperature influences both battery short term (capacity, efficiency, self-discharge) and long-term (lifetime) behaviour. Thus, thermal modelling of lithium-ion battery cells and battery packs is gaining importance. Equivalent thermal cir- cuits' models have proven to be relatively accurate with a low computational burden for the price of low spatial resolution; nevertheless, they usually require expensive equipment for parametrization. Recent research initiated by Barsoukov et al. proposed electrothermal impedance spectroscopy as a novel and non-destructive method of characterizing the thermal properties of batteries by defining frequency dependent thermal impedance. Despite its usefulness, the electrothermal impedance spectroscopy method can be still improved in terms of e.g. accuracy and measurement time and it has a potential to be extended to new applications. Performed review indicates that the electrothermal impedance spec- troscopy is a very promising, non-destructive, simple and especially cost-efficient method for thermal characterization of batteries. The scientific intention of this paper is to collect and systematize the state of knowledge about electrothermal impedance spectroscopy and present different measurement methods on the example of a high-power lithium battery cell and finally to discuss the prospect. © 2016 Elsevier Ltd. All rights reserved. 1. Introduction Lithium-ion (li-ion) batteries have dominated very quickly the market of portable electronics and they currently start to enter markets of electro-mobility and grid energy storage (Oliveira et al., 2015; Golembiewski et al., 2015). Nevertheless, the standards for li- ion batteries are constantly raised in order to meet the re- quirements of the more and more demanding applications (Kushnir and Sand en, 2011; Sen et al., 2016). Undergoing research on li-ion batteries results in increasing both energy and power densities of the state of the art li-ion batteries. Some li-ion battery technologies, e.g. lithium metal oxide cathode and lithium titanate oxide anode (LiMO 2 /Li 4 Ti 5 O 12 ) have currently continuous power capabilities higher than 10 C (full discharge within 6 min) and pulse power capabilities higher than 20 C (13Ah Altair Nano lithium titanate battery cell datasheet, 2011). For many years, there was very little interest in thermal modelling of the li-ion batteries because they were mainly employed in low-power applications. However, this has changed recently together with the development of high-power li-ion bat- teries. Nowadays ambitious goals of new battery applications, e.g. 10e15 years lifetime of electric vehicles (EVs), impose a good un- derstanding of lithium-ion battery thermal issues. The high power capability of the most state of the art battery cells drives the need for accurate and cost-efficient thermal modelling of the li-ion batteries in order to estimate heat genera- tion on the cell level. Moreover, battery thermal models are required to facilitate the optimal battery pack design with a cost- effective heat management. Battery temperature has an influence on many parameters of the li-ion battery like capacity, efficiency, * Corresponding author. E-mail address: mas@et.aau.dk (M. Swierczynski). Contents lists available at ScienceDirect Journal of Cleaner Production journal homepage: www.elsevier.com/locate/jclepro http://dx.doi.org/10.1016/j.jclepro.2016.09.109 0959-6526/© 2016 Elsevier Ltd. All rights reserved. Journal of Cleaner Production xxx (2016) 1e9 Please cite this article in press as: Swierczynski, M., et al., Electrothermal impedance spectroscopy as a cost efficient method for determining thermal parameters of lithium ion batteries: Prospects, measurement methods and the state of knowledge, Journal of Cleaner Production (2016), http://dx.doi.org/10.1016/j.jclepro.2016.09.109