November 05, 2019: Patent for graphite-carbohydrate active material particles with carbonized carbohydrates granted to StoreDot
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 methods of making anode active materials that include milling graphite particles with carbohydrate particles to yield graphite-carbohydrate particles, milling the particles with anode material, and carbonizing to form composite anode material particles.
The anode active materials thus produced are provided with an at least partially porous carbon-graphite coating with both electronic and ionic conductivity.
Improved anodes and cells are provided, 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.
Various anode active materials and combinations, modifications through nanoparticles, and a range of coatings that implement the improved anodes are provided.