OCV hysteresis and heat evolution – studying batteries with calorimetry

Heat release during cycling of battery half-cells is investigated by a combination of electrochemical methods and isothermal micro-calorimetry with special emphasis on Li- and Mn-rich NCM cathode active material. Due to its pronounced hysteresis in the open-circuit voltage (OCV), the energy round-trip efficiency is significantly reduced in comparison to a regular NCA cathode. But how and when is this energy loss converted into waste heat?

Franziska Friedrich completed her undergraduate studies at Ludwig-Maximilians University in Munich (LMU), where she received her bachelor’s degree in chemistry and biochemistry in 2016 and her master’s degree in 2018. The focus of her undergraduate studies at LMU were on electrochemistry, inorganic solid-state chemistry and material’s sciences. For her PhD, she joined the group of Prof. Hubert A Gasteiger for Technical Electrochemistry at Technical University of Munich (TUM) in 2018, where her research was centered on cathode active materials used for Lithium-Ion Batteries. Friedrich investigated aging phenomena of Ni-rich cathodes and published a JECS Editor’s Choice article in this research field. Furthermore, she studied hysteresis phenomena in Li-, and Mn-rich NCMs with potentiometric entropy measurements and isothermal micro-calorimetry to understand the effect of the hysteresis on the heat evolution of this type of cathode active material. In 2022, she received her PhD summa cum laude. Friedrich is currently working as a battery specialist for the BMW AG where her research interests mainly focus on all-solid-state batteries.