Patent Application
20160351865
The present technology relates to battery cells, including laminated pouch battery cells having improved electrical isolation and methods to fabricate such battery cells.
This section provides background information related to the present disclosure which is not necessarily prior art.
A battery cell can provide a clean, efficient, and environmentally responsible electrical power source for various applications, including powering a hybrid or purely electric vehicle. One type of battery cell is a lithium-ion battery. The lithium-ion battery can be rechargeable and can be formed into a wide variety of shapes and sizes to efficiently fit within the available space of the electric vehicle. For example, the battery cell may be prismatic in shape to facilitate a stacking of the battery cells. A plurality of individual battery cells can be provided in a battery assembly to provide an amount of electrical energy sufficient to operate the electric vehicle.
A prismatic battery cell can have a pouch shape formed by a pair of laminate sheets, including various plastic and metallic layers, that are fused or heat sealed around a periphery of an electrochemical cell to seal the battery cell components therein. For example, the pouch can be formed by one or more metal foils sandwiched by thermoplastic layers. Assembly of the battery cell can include providing one of the laminate sheets with a depression or cavity. The electrochemical cell components are disposed within or on the depression or cavity of the plastic coated metal layer. The other laminate sheet is then placed on top of the battery cell components and the peripheries of the laminate sheets are fused together, for example, by heat sealing around the edges to form a sealed pouch.
Effective use of the battery cell can depend on electrically insulating various portions of the battery cell, maintaining desired electrically conductive pathways, and optimizing integrity of the battery cell components. Various materials and fluids can conduct electricity during charging and discharging cycles of the battery cell. With respect to the pouch material, one or more metallic layers in the laminate can provide a hermetic seal barrier for the electrochemical cell. Maintaining electrical neutrality of the metallic layer from the surrounding components can be important in certain applications, such as vehicle battery packs, for improved performance and longevity of the battery cell. Proper insulation of the metallic layers can improve electrical isolation.
There is a continuing need to optimize battery assembly and component integrity while maintaining electrically insulated portions of the battery cell and maintaining desired electrically conductive pathways of the battery cell.
The present technology includes articles of manufacture, systems, and processes that relate to battery cells having a pouch formed of a flexible laminate with one or more terminals projecting therefrom.
Battery cells are provided that include an electrochemical cell having a terminal and a flexible laminate configured as a pouch. The pouch defines an interior and an exterior, where the electrochemical cell is disposed in the interior. The pouch includes a folded edge of the flexible laminate having a perforation therein, where the terminal is disposed through the perforation with a portion of the terminal exposed to the exterior of the pouch. The flexible laminate can include a barrier layer, where the barrier layer can be a metallic layer that can be electrically conductive.
Methods of making a battery cell are provided that include perforating a flexible laminate to form a perforation therein. A terminal of an electrochemical cell is disposed through the perforation. The flexible laminate is formed into a pouch, where the pouch defines an interior and an exterior. The electrochemical cell is disposed in the interior and the terminal is disposed through the perforation. A portion of the terminal is exposed to the exterior of the pouch. The flexible laminate can be folded to form a folded edge where the perforation is located on the folded edge.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.
The following description of technology is merely exemplary in nature of the subject matter, manufacture and use of one or more inventions, and is not intended to limit the scope, application, or uses of any specific invention claimed in this application or in such other applications as may be filed claiming priority to this application, or patents issuing therefrom. Regarding the methods disclosed, the order of the steps presented is exemplary in nature, and thus, the order of the steps can be different in various embodiments where possible. Except where otherwise expressly indicated, all numerical quantities in this description are to be understood as modified by the word “about” and all geometric descriptors are to be understood as modified by the word “substantially” in describing the broadest scope of the technology.
The present technology is drawn to various battery cells, including a battery cell that has an electrochemical battery cell and a flexible laminate. The electrochemical battery cell can have at least one terminal and the flexible laminate can be configured as a pouch. The pouch can define an interior and an exterior where the electrochemical battery cell can be disposed in the interior. The pouch can have a folded edge of the flexible laminate including a perforation formed in the folded edge. The terminal can be disposed through the perforation where a portion of the terminal can be exposed to the exterior of the pouch.
Various methods of making such battery cells are provided, where methods can include perforating the flexible laminate to form the perforation therein. The terminal of the electrochemical battery cell can be disposed through the perforation. The flexible laminate can be formed into the pouch, where the pouch defines an interior and an exterior. The electrochemical battery cell can be disposed in the interior and the terminal can be disposed through the perforation so that a portion of the terminal can be exposed to the exterior of the pouch.
Embodiments of the present technology are further described by reference to
With reference to
The embodiment of the flexible laminate 100 shown in
With reference to
With reference to
With reference to
Sealing of the joined edges 165 with the material 190 (e.g., electrically insulating tape) can serve to electrically insulate any exposed electrically conductive layers at the edge of the flexible laminate 100. For example, a barrier layer of the flexible laminate 100 formed of a metallic layer can be electrically conductive and can be exposed about the periphery of the flexible laminate 100; e.g., the aluminum layer 115 shown in
The present technology accordingly provides several benefits and advantages in optimizing the assembly and performance of the battery cell 150. Application of the material 190 (e.g., electrically insulating tape) about the periphery of the battery cell 150 is simplified by the use of the folded edge 160 with the terminals 155 disposed through the perforations 145, as it is not necessary to apply the material 190 along the folded edge 160. Unlike the joined edges 165, the folded edge 160 does not have an exposed barrier layer like a metallic/conductive layer (e.g., aluminum layer 115 in
Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms, and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail. Equivalent changes, modifications and variations of some embodiments, materials, compositions and methods can be made within the scope of the present technology, with substantially similar results.
