Effective thermal management is the most critical in ensuring the quality of lithium-ion batteries. When exposed to abnormal conditions such as external shocks damaging the cells, the internal pressure and temperature of the battery can rapidly rise, potentially causing heat to propagate to adjacent cells. Technologies that prevent this thermal propagation are gaining significant attention as essential components in securing the safety of EVs. As the number of battery cells, their capacity, and energy density increases to enhance driving range and performance, the impact of thermal propagation has become more severe than before. 

To address this, SAMSUNG SDI developed the No TP (No Thermal Propagation) technology and completed the review for commercialization recently. No TP is a comprehensive technology designed to prevent thermal propagation within battery cells, modules, and packs. Vehicles equipped with SAMSUNG SDI’s No TP technology can maximize usability by replacing only specific cells or modules in case of battery issues. Additionally, this technology prevents fire from spreading to the entire vehicle, nearby vehicles, or buildings, making it highly efficient in terms of social costs. 

The key enabler of this technology is SAMSUNG SDI’s propriety Thermal Propagation calculator (TPc), a unique program for predicting thermal propagation performance. It defines and quantifies key factors related to thermal propagation, measuring the impact on adjacent cells when an issue arises in a specific cell. As a result, optimal structural designs can be developed to prevent thermal propagation. SAMSUNG SDI’s No TP technology is not only applied to cell production but also serves as a No TP solution during the module and pack assembly process. 

In practice, SAMSUNG SDI’s batteries incorporate an optimized No TP design based on this thermal propagation prediction program. A key feature is the insulation sheet placed between cells, which is selected based on the predicted total heat generation of each cell. This material physically blocks heat transfer to adjacent cells when a specific cell’s temperature rises.

[SAMSUNG SDI’s No TP design to prevent thermal propagation]

Furthermore, the structural characteristics of SAMSUNG SDI’s prismatic batteries also contribute to effectively blocking thermal propagation, enhancing overall safety. First, the electrode plates in the battery utilize a stacking method, where substrates are layered in an orderly manner. This design reduces internal pressure within the case, as the microscopic gaps between the stacked materials allow gases generated inside to disperse in all four directions. 

Additionally, SAMSUNG SDI’s prismatic cell component, the vent, facilitates the release of high-temperature gas and flames, directing them into empty spaces within the pack. These spaces are also insulated, so the gas does not affect other cells during the release process.

[Structural safety of SAMSUNG SDI’s prismatic batteries]

With No TP technology, SAMSUNG SDI will continue its efforts to develop high-capacity, safe battery solutions.