Heat is a lithium-ion battery’s greatest enemy. Batteries generate heat when they discharge electricity, and they are often placed in hot environments or in direct sunlight. Regardless of the source of the heat or the specific battery chemistry, when lithium-ion batteries get too hot, three bad things can happen: cycle life decreases, battery performance decreases, and the risk of a battery fire or explosion increases.
AllCell has found a solution to the thermal management challenge that is simple, lightweight, low cost, and passive. AllCell uses a phase change material combined with graphite to manufacture a composite material that provides effective protection against heat.
The lithium-ion cells in the battery pack are placed in direct contact with our PCC. As the pack heats up, the graphite spreads the heat evenly throughout the pack, avoiding hot spots and ensuring temperature uniformity. Once the temperature reaches the melting point of the PCC, all additional thermal energy is absorbed by the melting process rather than continuing to raise the temperature. More details on the PCC™ technology can be found here.
AllCell produces several standard versions of the PCC™ material available for purchase for battery and non-battery applications (see data sheet here), and customized versions can be designed with different thermal, mechanical, and electrical properties.
For applications using cylindrical cells, the most common design is a rectangular block with holes provided for easy cell insertion. Other designs are also possible, including using small triangular or diamond-shaped PCC™ pieces as spacers between cells.
Applications using prismatic cells typically utilize flat sheets of PCC™ sandwiched between each cell. Depending on the amount of physical expansion and contraction of the cell during cycling (“breathing”), foams or other flexible materials may also need to be included in the design. AllCell is developing a new phase change composite with improved physical properties that provide improved performance with most prismatic cells. Please contact us if you would like to collaborate with us as we develop this new product.