Advanced Electrolyte for Next Generation High-Energy Lithium Metal Batteries

Lithium ion (Li-ion) battery is now the dominant energy storage system in portable electronics and electric vehicles (EV). The rapid expanding EV is driving the demand for next generation high-energy batteries. Compared to conventional Li-ion batteries with graphite anode, which has a theoretical capacity of 372 mAh/g, lithium-metal batteries can deliver ten times of specific capacity (3860 mAh/g). Theoretically, anode-free batteries can double the energy density in volume compared to Li-ion batteries at the cell level. However, current anode-free batteries suffer from faster capacity decay due to poor lithium plating on Cu foil.

To overcome this challenge, the technology owner has developed a liquid electrolyte comprising lithium difluoro(oxalate)borate (LiDFOB) and a carbonate solvent, enabling reversible lithium plating of anode-free lithium metal batteries. This electrolyte ensures good thermal stability with smooth Li plating of counter electrode on the anodic side even at elevated temperatures. It facilitates a capacity retention of above 80% after 100 cycles for an anode-free battery or 80% after 400 cycles for a battery with a Li metal anode.

The technology owner seeks collaboration with industrial partners such as battery developers and manufacturers for further co-development and test-bedding of electrolyte and subsequent licensing of this technology for commercialisation.

The patented technology is an electrolyte comprising lithium difluoro(oxalate)borate (LiDFOB) dissolving in an organic carbonate solvent that has the following features:

• High concentration of the LiDFOB in the range of 1.5M to 3M
• Enable smooth and reversible lithium plating / stripping
• Good cycling performance and high charging rate
• Good thermal stability enabling high operating temperature (up to 80 °C)
• Good electrochemical stability compatible to high voltage cathodes

The patented electrolyte can be applied to high-energy lithium ion batteries, which have the following potential applications:

• Aerospace and aviation (drones and satellites)
• Electric vehicles (EVs, HEVs)
• Grid-scale energy storage
• Backup power systems

• Enable smooth and reversible lithium plating
• Higher energy density (about 30% increase in gravimetric capacity)
• Good thermal stability and cycling performance
• Enable high-energy-density anode-free lithium metal batteries