|Thin film batteries (TFB) have the potential to become the next generation of lithium batteries for portable electronic applications; however, there is a large gap between the results obtained in the laboratory and the commercial products.For example, until now, most TFBs have only a very limited shelf life outside the glove box. These batteries also needed to be annealed at high temperature (~ 700ºC), a process not compatible with many realistic substrate materials such as polymers or integrated circuit boards. Excellatron has overcome these barriers and is today able to produce commercial products. To date, Excellatron has filed 20 patent applications, with ten patents issued or allowed in the field of thin film batteries, and has accumulated a wealth of production know-how and trade secrets in the manufacturing of thin film batteries.
Excellatron's first commercial product was designed for smart cards and other flexible electronic devices. This product is protected by several key Excellatron patents. One patent describes the materials and process to produce TFBs on polymer (such as Kapton) substrate. It includes a low temperature manufacturing process (<350ºC) which allows the use of a polymer substrate such as Kapton, thereby significantly reducing manufacturing cost while gaining flexibility and significantly reducing the overall thickness of the battery cells. Another Excellatron patent describes a unique packaging solution for flexible batteries. The passivated cells are sandwiched between the packaging foils, the whole cell assembly (instead of only the edge of the cell assembly as reported by prior art) is passed through a roller or platen laminator to form a monolithic battery structure.A unique packaging foil was selected so that both the cell and packaging foil are not damaged during the high temperature (130ºC) and high pressure (200N/cm²) lamination process. This novel packaging solution, in combination with Excellatron's invention to deposit thin film batteries on Kapton substrate, can also be used in the development of high capacity batteries for cellular phone applications.
Excellatron also holds patents in several other key areas of the development and production of TFBs. These include three issued patents on a method to produce high capacity TFBs on both sides of a very thin aluminum substrate. Two patents are pending on production of thin film batteries by using atmospheric pressure chemical vapor deposition which can reduce the production cost of electrolyte and cathode by an order of magnitude. Two patents are pending on plasma enhanced chemical vapor deposition of LiPON and cathode materials which can increase the deposition rate from 3 to 10 times compared to sputtering. Three patents are pending on high temperature packaging methods for TFBs which allow packaged batteries to endure temperatures up to 260ºC (necessary for the solder reflow process utilized in the semiconductor industry).
Excellatron has not only developed TFB production technology, but has also made advances on new materials for TFBs. For example, Excellatron invented a high capacity anode which has a capacity of 2,250mAh/g, far exceeding other lithium ion intercalation compounds reported to date (patent pending). Two other patents issued to Excellatron describe methods for making an Sn:Li3N anode and a Li:metal alloy based anode. Excellatron also has a pending patent that describes a method to reduce switching noise in an integrated circuit by adopting thin film batteries as distributed power sources.Excellatron's unique technologies covering the substrate, cathode deposition, passivation and packaging have enabled us to produce revolutionary new batteries that can be used in many processes and applications that were not possible before. These batteries are ideally suited for applications that require a high temperature compatible, compact, safe, and high power rate battery. They are ideally suited for applications such as smart cards, cellular phones, and other portable electronics.