APPLICATIONS OF TECHNOLOGY:
- Solid state batteries for:
- Electric vehicles
- Consumer electronics
- Safer than traditional lithium-ion batteries
- Sustainable production
- Inexpensive cathode materials
- Potentially higher energy density than current technology
- Enables innovative cell assembly
- Lithium-ion batteries are essential to many modern electronics, but they come with a number of drawbacks. Traditional lithium-ion batteries rely on cathodes made from rare and expensive transition metals like cobalt, which also require environmentally harmful mining practices. Additionally, the organic electrolytes used in lithium-ion batteries are toxic and flammable, posing a safety risk in the event of physical damage to the battery cell. There is also potential for higher energy density in different battery chemistries, meaning the continued reliance on transition metal cathodes limits the applications of batteries, especially in transportation.
Berkeley Lab researchers have developed a battery cell with a solid electrolyte based on a quinone cathode, which has a theoretical energy density of 496 mAh/g, compared to nickel manganese cobalt (NMC) cathodes with an energy density on the order of 200 mAh/g. One issue facing adoption of organic cathodes, though, is poor capacity retention. Small, organic molecules like quinones are easily soluble, meaning the cathode can dissolve in liquid electrolytes and react with the anode. Using a lithium garnet (LLZO) solid electrolyte addresses the dissolution problem by physically confining the cathode material.
Researchers tested different quinones to determine which particular molecules provided the highest energy density and also good capacity retention. With a metallic Li alloy as the anode and lawsone, a biologically-derived quinone, as the cathode, cells were shown to retain a capacity greater than 200 mAh/g after 25 charging cycles, demonstrating the potential value of organic cathodes as replacements for traditional NMC cathode materials.
DEVELOPMENT STAGE: Characteristic proof of concept
- Michael Tucker
STATUS: Patent pending.
OPPORTUNITIES: Available for licensing or collaborative research.