We are developing high-speed spectroscopic and microscopic methods to characterize the thermal runaway process from next-generation batteries. We have developed a unique test capability to induce controlled thermal runaway failure of a variety of form-factors ranging from cylindrical, pouch and prismatic cells. Cells are housed inside a custom-fabricated battery test chamber that enables complete optical accessibility for our lasers and cameras. We develop and undertake a range of spectroscopic measurements ranging from UV to IR. A key innovation with our approach is that measurements are performed in-situ allowing for a local snapshot of the thermo-chemical state of the thermal runaway process. This enables us to characterize battery performance and compare different batteries to evaluate their hazards.

We are equipped with a range of state-of-the-art equipment including a high-speed laser, high-resolution spectrometer, long-distance microscope, Fourier-Transform Imaging camera, and a high-speed camera.

Current projects and capabilities include:

• Hyperspectral imaging of flammable and toxic species emitted from a lithium-ion battery during safety venting

• Fast optical emissions spectroscopy to perform pyrometry and quantify the temperature field of hot ejected particles from batteries

• In-situ particle sizing using long-distance shadowgraph and time-resolved laser-induced incandescence

• Quantification of the local particle velocity field and ensemble statistics

We work with