{"id":522,"date":"2018-12-21T00:00:00","date_gmt":"2018-12-21T00:00:00","guid":{"rendered":"https:\/\/www.innovationnewsnetwork.com\/battery-calorimetry-increased-safety\/522\/"},"modified":"2020-06-23T12:45:34","modified_gmt":"2020-06-23T11:45:34","slug":"battery-calorimetry-increased-safety","status":"publish","type":"post","link":"https:\/\/www.innovationnewsnetwork.com\/battery-calorimetry-increased-safety\/522\/","title":{"rendered":"Battery calorimetry for increased safety"},"content":{"rendered":"

Dr Carlos Ziebert, head of the Calorimeter Centre at Karlsruhe Institute of Technology\u2019s Institute of Applied Materials \u2013 Applied Materials Physics, outlines how research and testing in battery calorimetry<\/a> is crucial to safety development.<\/h2>\n

Established in 2011, the Calorimeter Centre at the Karlsruhe Institute of Technology\u2019s (KIT) Institute for Applied Materials \u2013 Applied Materials Physics (IAM-AMP), now operates Europe\u2019s largest battery calorimetry laboratory. It provides six Accelerating Rate Calorimeters (ARCs) of different sizes \u2013 from coin to large pouch or prismatic automotive format, which allow the evaluation of thermodynamic, thermal and safety data for Lithium-ion and post-Lithium batteries on material, cell and pack level for both normal and abuse conditions (thermal, electrical, mechanical).\u00a0 With these facilities, and the established expertise, the IAM-AWP is now seen worldwide as one of the few institutions that investigates both the thermodynamics and the safety of batteries and their materials. It is clear that safety issues have a major influence on consumers\u2019 willingness to adopt battery systems.<\/p>\n

Safety first<\/h3>\n

Safety comes first\u2013 this is the mission of the battery calorimetry centre\u2019s head, Dr Carlos Ziebert. The development of safe cells is of great importance for a breakthrough of the electrification of transport and for stationary storage, because an uncontrollable increase in temperature of the entire system \u2013 so-called thermal runaway \u2013 can cause an ignition, or even explosion, of the battery with simultaneous release of toxic gases. Thermal runaway is, of course, something that nobody wants, especially in an electric car or another electric vehicle; the causes and effects of this can be very diverse and complex (see Fig. 1). Either internal or external mechanical operating or thermal stresses lead to an internal heating of the cell that initiates different exothermal reactions, followed by a further temperature and pressure increase. The final effects can be empirically classified by the Hazard Level (1-7).<\/p>\n

Cell designs, component integrity, manufacturing and ageing processes all have critical influence on the safety of Li-ion batteries. To avoid thermal runaway, the system must be designed optimally on material, cell, pack and system level for the technical and commercial requirements. As such, it is crucial to conduct thermodynamic studies of the thermal effects together with the material and cell development for advanced and even post-Lithium systems. Thus, the complete scientific and technical understanding of these effects is of utmost importance.<\/p>\n

Benefits of battery calorimetry<\/h3>\n

Calorimetry \u2013 or the process of measuring heat data during chemical reactions \u2013 allows the collection of quantitative data required for optimum battery performance and safety. Sophisticated battery calorimetry, combined with thermography, allows new and quantitative correlations to be found between different critical safety and thermally related parameters. This is very important as you need to know how many Watts a cell will produce under every condition, in order to adapt the battery and thermal management systems. The temperature, heat and internal pressure evolution can be studied, while operating cells under conditions of normal use, abuse or accidents. Such abuse tests without the benefit of battery calorimetry have two main disadvantages:<\/p>\n