APPLICATIONS OF TECHNOLOGY:
- Li-ion batteries (e.g., in vehicles)
- Charge transfer resistance at low temperature is reduced significantly
- Additive can be used with the standard electrolyte at room temperature
- Electrolyte maintains all of its stability and is able to perform better at low temperatures
Battery performance at lower temperatures is dictated by the discharge power capability at low state of charge. At low temperatures power is limited by charge transfer kinetics; it appears that poor charge transfer is associated with the properties of the CEI on the cathode active material. Alternative electrolytes have completely different solvents and salts formulated for higher conductivity at low temperatures and typically fail at higher temperatures. Therefore, there is a need for a battery that has low resistance at low states of charge at low temperatures.
Researchers at Berkeley Lab have developed an invention that introduces particles to an electrolyte to improve low temperature performance.
At 30 °C, the cell with Gen2-X (5 wt%) demonstrated good cycling performance and excellent coulombic efficiency. As Li-ion batteries showed a marked increase in impedance at temperatures below -5 °C, with the addition of less than 2% particles to the electrolyte prior to the introduction of the electrolyte into a cell, the cell’s accessible capacity and energy was improved by as much as 11%. This is a major development of Li-ion battery technology, as this change results in Li-ion batteries meeting the low temperature performance requirements agreed upon by the three major car companies in the U.S.
Future work will involve the optimization of the content of additives in the electrolyte of Gen2+X and the characterization of the Gen2-X electrolyte (DSC, FTIR, etc.).
DEVELOPMENT STAGE: Proven principle
STATUS: Patent pending.
OPPORTUNITIES: Available for licensing or collaborative research.