Description:
Reference #: 01088
The University of South Carolina is offering licensing opportunities a single-step approach for synthesizing novel electrodes for lithium ion batteries in large quantities.
Invention Description:
The subject invention is a facile and scalable process to synthesize bulk electrodes for lithium ion batteries. These electrodes exhibit superior electrochemical properties and provide an ideal structure for lithium ion batteries that results in high power density, capacity retention, and overall improved performance.
Potential Applications:
Developing cost-effective anode materials for the next generation of lithium ion batteries
Advantages and Benefits:
1. Exhibits 5x the capacity of conventional graphite anodes used in lithium ion battery technology
2. Utilizes a scalable, single-step approach compared to expensive and hazard processes used by current technology to create electrode materials
3. Yields the electrodes in bulk form (kilograms) whereas current technology only generates thin films and ultrafine participles (grams and milligrams and grams), making it suitable for manufacturing applications
Background:
Generally, the power density of a lithium ion battery is limited by its negative electrode. Current battery anodes consist of graphite, which has a low capacity (372 mAh/gram) and exhibits slow charge rates, which results in poor performance. Furthermore, a dendrite layer may form causing thermal runaway and battery burning.
High performance negative electrode materials like silicon (4200 mAh/gram) and tin (994 mah/gram) seem promising because of their superior electrochemical properties, low cost, and environmentally friendliness. However, achieving stable performance requires large volume changes during operation that damage the anode materials and leads to a loss of electric contact between anode particles and the current collector. The processes used to mitigate the detrimental effect of these volume changes include incorporating graphene matrices into the anode material to form composites, synthesizing intermetallic compounds that buffer volume fluctuation, and altering the morphology of the electrodes.
The electrode material outlined in this invention (1620 mAh/gram) is useful because of its isotropic lithiation, electronic conductivity, and lithium diffusivity. Recent in-situ TEM studies revealed that the electrodes are able to sustain large volume changes during operation unlike silicon and tin by expanding and contracting in a uniform manner.
Experimental Validation:
These electrodes showed high power density of approximately 1500 mAh/gram (compared to graphite) and retained 99% of its charge over the course of testing. Further research is being carried out to improve capacity retention at substantially higher rates.