Scalable, Cost-effective Calorimeter for Thermal Monitoring of Batteries

Battery cells must be tested for performance and operational reliability from the design phase to the production process, to safeguard its safety, reliability and cost. As batteries are prone to temperature-related issues, like overheating and overcharging, there can be extreme spikes in temperature known as ‘thermal runaway’. In order to evaluate the thermal performance of the battery, calorimetric testing can produce data that indicates defects at an early stage and thus help to predict a ‘thermal runaway’ at a later stage. 

A German research institute has developed a modular, scalable calorimeter to measure the thermal data of batteries of diverse cell sizes. The scalable system is suitable for applications in thermal monitoring from new module designs to new battery materials and quality assurance.

The modules are currently in use at the research institute and this calorimeter has German utility model protection. The research institute is searching for partners for the joint further development in research cooperation agreements or for partners interested in a direct license.

Typically, the calorimetric testing of battery cells is based on measuring systems that are designed for specific battery cells. A full encapsulation is often chosen to achieve the required calorimetric, metrological accuracy and to limit any damage arising from cell failure. These special, battery-specific designs are quite expensive, adding to the costs in the event of "thermal runaway". 

The technology on offer uses a modular system of almost identical assemblies which allows high-precision calorimetric measurements in a simple modular construction that is scalable for different battery sizes, and is particularly suitable for prismatic or pouch cells. 

With a low-cost design, there is little financial loss if 'thermal runaway' occurs on a defective battery cell. In addition, as the surface size of the usual battery cells is variable, the modules allow for easy scaling of the surface area with an almost identical design. Different design sizes are covered without the need to purchase a new measuring device, and any loss due to 'thermal runaway' can be compensated by quickly reassembling a module set. 

This technology is versatile and is suitable to derive calorimetric measurements in the following areas:

• Development phase of new module designs and of new battery materials in order to detect weaknesses in the design
• Quality assurance of random samples from ongoing production

The benefits of this system include the following:  

• Easily adaptable to different battery module sizes 
• Highly accurate, enabling high precision in thermal measurement 
• Low cost due to identical scalable parts 
• Especially suitable for prismatic and pouch cells
• Suitable for use in the lifecycle of battery development, from new module designs as well as new battery materials, and quality assurance, to detect weaknesses in the design
• Easy scalability due to modular format