Infinite Power Solutions, Inc. (IPS) has been granted a key battery encapsulation patent by the United States Patent and Trademark Office (USPTO). U.S. Pat. No. 8,236,443 entitled, "Metal Film Encapsulation," represents an ultra-thin, flexible encapsulation with a hermetic seal for use in manufacturing long-lasting, solid-state, thin-film batteries (TFBs). This high performance metal film encapsulation provides a significant competitive advantage for the company and is already in use to produce its THINERGY® family of Micro-Energy Cell (MEC) products.
IPS' first battery encapsulation patent, U.S. Pat No. 6,916,579 granted in 2005, was for the initial invention of a metal foil encapsulation for thin-film batteries. This second patent expands on the first, in part, by including a vertical conducting element that eliminates the need for peripheral current collectors as invented by Oak Ridge National Labs in the 1990s. Such peripheral current collectors are commonly used in other thin-film batteries and necessitate a larger footprint. IPS' patented conductive feature in the vertical direction, combined with the metal film encapsulation as a current collector and terminal, maximizes the active area efficiency. This means more power and higher capacity per unit area than other TFBs. In addition, the metal film encapsulation is peripherally bonded to the cell's metal foil substrate to form a tiny metal cage around the cell and, therefore, a hermetic seal. The dual purpose substrate layer (both substrate and bottom half of the cell encapsulation) reduces cost and materials, simplifies the design and minimizes cell thickness.
Conventional prismatic lithium ion batteries use a pouch style package where the cell substrate is in addition to the top and bottom metallized polymer foils forming the pouch (adding thickness), and the current collectors are peripheral to the cell (adding area). Other TFB encapsulations, such as polymeric and ceramic materials have been used by some developers but lack a sufficient moisture and oxygen barrier, a characteristic which is vital for a battery containing a metallic lithium anode. Such non-metallic encapsulations allow high moisture vapor and oxygen transmission rates resulting in cell degradation within months, even in low humidity environments. In contrast, the IPS metal film encapsulation provides cell protection for more than a decade.