Patent Battle Heats Up For Lithium Iron Phosphate Batteries

In the world of batteries, Lithium-ion batteries are dominant in laptops, cell phones, and other mobile devices because of their ability to store lots of energy in a small, light package. However, if the batteries are damaged or or experience an internal short, the unstable materials in the battery release oxygen, oxidizing other materials in the battery, which in turn produces more heat. The cycle continues in a process called "thermal runaway," which in some cases can lead to a violent explosion. This is theorized to be the reason for the recent battery recalls for laptop computers.

In the new lithium-ion phosphate batteries, cobalt oxide is replaced with iron phosphate, which is considered to be a much more stable material. Manufacturers of lithium-ion phosphate batteries have even released videos showing batteries getting nails rammed into them without any sort of explosion.

Not surprisingly, these new batteries have started to appear in many industrial applications, and are odds-on favorites as a battery of choice for electric and hybrid vehicles (they're already being used in the Segway). It's estimated that the market for these types of batteries will approach billions in the years to come.

One company that manufactures these and other similar batteries is A123 Systems Inc., which has already released lithium phosphate batteries for use in Black & Decker's new line of DeWalt 36-volt power tools. In the meantime, the Board of Regents of the University of Texas, which owns U.S. Patents 5,910,382 and 6,514,640 (both titled "Cathode materials for secondary (rechargeable) lithium batteries") joined Hydro-Quebec, who is the exclusive licensee, in suing A123 Systems, Black & Decker and China BAK Battery, Inc. for allegedly infringing the two patents. The case was filed in the Northern District of Texas, Dallas Division.

There are reports that A123 Systems has already started an offensive of their own on a newly issued patent, but this has not been verified by the 271 Patent Blog.

In the complaint, the Board of Regents claims to have invented the core technology for lithium iron phosphate batteries through the research of Dr. John Goodenough and others within UT's Material Science and Engineering Department. Claim 1 of the '382 patent reads as follows:

Claim 1. A cathode material for a rechargeable electrochemical cell, said cell also comprising an anode and an electrolyte, the cathode comprising a compound having the formula LiMPO4, where M is at least one first-row transition-metal cation.

The Board of Regents is seeking a preliminary injunction, along with unspecified damages. You can view the complaint here.

See MIT article on A123 System's battery technology here.

See patent mapping of A123 System's technology here (January 2006), courtesy of tecpatents.com.