CMC-1 Solid State Electrolyte
Thermal Stability of Solid Ultra Battery’s CMC-1 Membrane vs Commercial Polymeric Membrane
At the heart of our solid state lithium metal battery technology is the proprietary solid electrolyte/separator (SSE), CMC-1 which is a flexible solid electrolyte separator that is stacked between the anode and cathode. CMC-1 acts as a barrier and prevents lithium dendrites from forming on lithium metal anodes and ultimately snaking between the electrodes during charge cycles causing a short circuit that could lead to a battery fire. In conventional lithium-ion batteries, polymer membranes are used as the separator material using liquid electrolytes and are inadequate failsafe against battery fires and dendrites particularly at high operating temperatures.
The above picture shows thermal testing of the CMC-1 membrane against a commercial polymeric membrane the is used in liquid electrolyte lithium-ion battery.
The results show that the CMC-1 Solid State Electrode maintained its structural integrity at elevated temperatures of 200°C with no loss of structural support. The commercial polymeric membrane was observed losing structural integrity at 120°C and subsequently appeared to disintegrate by 200°C. This loss of structural integrity in the current technology can result in a thermal runaway event of the battery due to internal short circuit if the polymeric membrane is breached. Commercialized lithium-ion battery technologies using polymeric membranes require a strict thermal management regiment and typically requires battery management systems to begin limiting battery discharge well below 70°C at the cell level for adequate margin of safety against thermal events.
Solid UltraBattery’s CMC-1 SSE superior thermal performance at wider temperature ranges ensures better stability while maintaining good ionic conductivity resulting in better capability to prevent internal short circuits. A higher level of product safety can be realized as this configuration will substantially lower the probability of thermal runaway. The CMC-1 SSE batteries will enable battery pack designers to employ lower cost thermal management strategies for failsafe operation of lithium metal batteries.