Mar 15 2006
Hitachi Chemical Company has developed a network of basic patents on carbon anode material for lithium ion batteries.
A lithium ion battery is a type of repeatedly-usable secondary battery that is charged and discharged through a reaction in which lithium ions move between the anode and the cathode. Being lighter and having a higher energy density and a longer life than conventional secondary batteries, lithium ion batteries are rapidly becoming widespread as secondary batteries that make it possible to develop high-performance and multifunctional portable devices such as cell phones, notebook PCs and digital cameras. In addition, they have potential applications as power sources for hybrid vehicles.
Carbon anode material is a carbon material used as the anode in lithium ion batteries. Our anode material consists of lump-shaped particles, unlike conventional anode materials in which the particles are flat. Each particle is a lump of randomly-aggregated fine flat particles. This allows the smooth movement of lithium ions, and thereby fast charging and discharging, which is difficult with conventional anode materials. This unique particle shape acts to absorb stress due to the movement of lithium ions, reducing damage to the anode and allowing a long use cycle. Our carbon anode material has a high reputation in the market, and we have the top share in the world.
We have filed patent applications on carbon anode materials for lithium ion batteries both in Japan and overseas since 1995, and have been working to develop a network of patents from the viewpoint of structure, physical properties and applications. In 2003, oppositions were filed against some of these patents, and we have been disputing their validity. Recently, the Japanese Patent Office made a decision to retain the patents. Consequently, we have developed a robust network of patents on this technology, including foreign patents.
We will take resolute action against patent infringements in order to protect our research achievements and products, and we intend to make use of our patents to the maximum extent possible. We also intend to differentiate our patents as our own proprietary technologies and will promote measures to enhance our patent network in order to retain and enhance our superiority in the market.
http://www.hitachi-chem.co.jp