United States Patent and Trademark Office >>
A major barrier in battery technology concerns safety requirements, particularly when batteries are overheated or overcharged, resulting in thermal runaway, cell breakdown and possibly fire or explosion.
Additionally, a short circuit or a design defect may also bring about battery failure resulting in fire and safety risks. Lithium ion batteries in particular, while having operational advantages, are potentially flammable due to their high reactivity, particularly when in contact with humidity.
The present invention relates to the field of energy storage devices, and more particularly, to fast charging lithium ion batteries.
This disclosure covers improved anodes and cells, which enable fast charging rates with enhanced safety due to much reduced probability of metallization of lithium on the anode, preventing dendrite growth and related risks of fire or explosion.
Anodes and/or electrolytes have buffering zones for partly reducing and gradually introducing lithium ions into the anode for lithiation, to prevent lithium ion accumulation at the anode electrolyte interface and consequent metallization and dendrite growth.
Claimed within this patent is an anode comprising anode active material particles which comprise at least one of a boron oxide, a phosphorus oxide, a borate, a phosphate and salts thereof, wherein at least one coating comprises a layer of B2O3, which replaces a native oxide on the surface of the anode active material particles.
Image source: Penn State