According to this piece in the Austin Business Journal, Valence recently won a four-year patent infringement suit against Montreal-based Phostech Lithium (Phostech). See also the Valence press release (Valence_press_release).
The patent-in-suit was Canadian Patent No. 2,395,115 (’115 Patent), entitled “Preparation of lithium-containing materials.
The ’115 Patent relates to lithium mixed metal phosphates for advanced batteries. The materials described in the patent include LiFe0.9Mg0.1PO4 and are used as the active material in a battery cathode.
According to the ’115 Patent, this material has a better charge capacity than existing lithium cathode materials. This is demonstrated in the different specific capacity between the LiFePO4, plotted in FIG. 2 of the patent, and the new material, LiFe0.9Mg0.1PO4, shown in FIG. 5.
The ’115 Patent explains that FIG. 5 (LiFe0.9Mg0.1PO4) shows a well defined and sharp peak at about 150 mAh/g (milliamp hours per gram), while FIG. 2 (LiFePO4) shows a shallow slope leading to a peak at about 123 mAh/g.
This means that the Fe-phosphate plotted in FIG. 2 provides 123 mAh/g compared to its theoretical capacity of 170 mAh/g, for only 72% specific capacity. The improved Fe/Mg-phosphate material provides 150 mAh/g compared to a theoretical capacity of 160 mAh/g, which is 94% specific capacity.
According to Phostech’s press release (Phostech_press_release), the Federal Court of Canada ordered Phostech to cease its current production and sale of lithium iron phosphate.
Eric Lane is a patent attorney at Luce, Forward, Hamilton & Scripps in San Diego and the author of Green Patent Blog. Mr. Lane can be reached at firstname.lastname@example.org.