Low temperature performance evaluation of electrochemical energy storage technologies
journal contributionposted on 02.03.2021, 09:18 authored by Ashley FlyAshley Fly, Iain Kirkpatrick, Rui ChenRui Chen
The performance of electrochemical energy storage technologies such as batteries and supercapacitors are strongly affected by operating temperature. At low temperatures (<0 °C), decrease in energy storage capacity and power can have a significant impact on applications such as electric vehicles, unmanned aircraft, spacecraft and stationary power storage. In this work, the discharge behaviour of nine different commercial electrochemical cells are evaluated, representing a variety of lithium-ion, nickel metal hydride, lead acid and supercapacitor technologies. Discharge capacity, energy, maximum power and impedance spectra with equivalent circuit analysis are compared at temperatures ranging from +20 °C to -70 °C. Results demonstrate that despite exhibiting the greatest loss in performance with temperature reduction, the lithium-ion batteries tested provide the highest energy and power densities down to - 30 °C due to higher capacity and operating voltage. At lower temperatures, the lead-acid cell gives the highest energy density and supercapacitor the highest power density. A new simplified empirical method is introduced for lithium-ion cells to determine the optimum pre-heating temperature for maximum net energy output including heating efficiency. This new method can be used to assess the benefits of different cold-start thermal management strategies for electric vehicles. It is also demonstrated that the temperature of the lithium-ion cells tested can be accurately predicted from impedance phase change at low temperatures across a range of electrode materials.
- Aeronautical, Automotive, Chemical and Materials Engineering
- Aeronautical and Automotive Engineering