Insulation Materials for EV Battery Cells to Prevent Short Circuits
45 patents in this list
Updated:
Electric vehicle (EV) batteries must be insulated effectively to prevent short circuits, which can cause failures or fires. The challenge lies in finding materials that provide sufficient insulation without adding excessive weight or bulk to the battery pack. As EVs demand higher energy densities and compact designs, ensuring electrical isolation becomes increasingly complex and critical.
Professionals in the field face the task of balancing insulation effectiveness with space and weight constraints. Traditional materials may not suffice, as they can fail under thermal stress or degrade over time. The stakes are high, as inadequate insulation can compromise both safety and performance, leading to costly recalls or reputational damage.
This page explores a range of solutions, such as gel-layer secured films, notched side insulations, and multi-layer insulating systems. These approaches aim to enhance structural stability and electrical isolation, while maintaining the compact, efficient design required by modern EVs. Through these strategies, we address the pressing need for reliable insulation in battery cells, ensuring safety and longevity in demanding environments.
1. Battery Pack with Gel-Layer Secured Insulating Film Surrounding Stacked Cells
BYD COMPANY LTD, 2024
Battery pack design for improved insulation and structure in battery packs, energy storage devices, and vehicles. The battery pack has a cell group with cells arranged in a stack. The cells are surrounded by an insulating film. Instead of sticking an insulating film on the cell surface, the film is fixed to the cell using a gel layer. This eliminates the need for an adhesive layer between the insulating film and cell. The gel layer also helps prevent wrinkles and bubbles in the insulating film. The insulating film is fixed to the cell through the gel layer. This improves insulation and reduces the risk of delamination between the cell and insulating film. It also avoids using adhesives between the film and cell, which can weaken the structural strength of the pack.
2. Battery Cell Arrangement with Opposing Poles and Intercell Insulation
CONTEMPORARY AMPEREX TECH CO LTD, CONTEMPORARY AMPEREX TECHNOLOGY CO LTD, 2024
Battery design to prevent high voltage ignition between cells without increasing spacing and losing energy density. The battery has cells arranged with opposite poles facing each other. Insulation is provided between the cells, with part of it located between the facing poles. This prevents voltage breakdown between the cells without increasing intercell spacing.
3. Battery Pack with Notched Side Insulation for Reduced Thickness and Electrical Isolation
ZHONGCHUANG XINHANG TECH GROUP CO LTD, ZHONGCHUANG XINHANG TECHNOLOGY GROUP CO LTD, 2024
Battery pack design to improve energy density and safety without increasing pack thickness. The pack has stacked batteries with insulation between them. The insulation has notches at the sides of adjacent batteries that align. This allows the pack to have less overall insulation thickness compared to fully covering the sides. The notches reduce pack thickness while still electrically isolating the batteries. The notch areas balance to provide sufficient insulation.
4. Battery with Stacked Cells and Insulating Component Between Cell Wall and Converging Lead Connector
NINGDE CONTEMPORARY AMPEREX TECH CO LTD, NINGDE CONTEMPORARY AMPEREX TECHNOLOGY CO LTD, 2024
Battery design to improve safety by preventing short circuits between the bus bar and case. The battery has stacked cells with a converging component connecting the cell leads. An insulating piece is placed between the cell wall and converging component to isolate and insulate the wall from the converging part. This prevents short circuits between the bus bar and case.
5. Insulating Plate with Two-Layer Structure Comprising Meltable Resin for Battery Electrode Separation
Panasonic Energy Co., Ltd., PANASONIC ENERGY CO LTD, Panasonic Energy (Wuxi) Co., Ltd., 2024
Insulating plate for battery, lithium ion battery, and battery pack to prevent short circuits, improve safety, and prevent explosions. The insulating plate has a two-layer structure with a first insulating plate and a second insulating plate sandwiched between the battery electrode group and the first plate. The second plate is made of a meltable resin with a lower melting point than the first plate. This prevents contact between bent positive electrode leads and negative electrodes. If the battery overheats, the second plate melts quickly to allow exhaust and prevent explosions.
6. Battery Pack with Stacked Cells and Solidified Inter-Cell Insulation for Enhanced Structural Stability
DONGGUAN POWERAMP TECH LTD, DONGGUAN POWERAMP TECHNOLOGY LTD, 2023
Battery pack design with improved shock resistance and ease of manufacturing. The battery pack has a cell module with stacked cells, a connecting structure that electrically connects the cells in a perpendicular direction, and insulation between the cells. The insulation is placed between adjacent cells and solidified to prevent internal cell movement during shock. This prevents cell damage and pack failure. The insulation connects to the cell walls and adjacent structure to prevent excessive cell movement. The insulation also reduces manufacturing complexity by preventing cell misalignment during packing.
7. Battery with Grouped Cell Arrangement and Insulation for Terminal Protection and Alignment
ZHONGCHUANG XINHANG TECH GROUP CO LTD, ZHONGCHUANG XINHANG TECHNOLOGY GROUP CO LTD, 2023
Battery design to reduce short circuits and improve reliability by preventing terminal exposure and cell misalignment. The battery has cells arranged in groups with insulation between adjacent cells. This allows more cells in the same volume, thinner electrodes, and faster charging. It also reduces friction and vibration between cells to prevent diaphragm damage and terminal shorts. The positive and negative terminals are on the same side of the case for easier interconnection.
8. Power Storage Module with Cured Adhesive Insulation Covering Conductive Connections
TOYOTA MOTOR CORP, 2023
Power storage module with improved insulation between conductive connections to prevent short circuits. The module has a cell stack with cells connected by conductive tabs. Insulating members made of cured adhesive cover the conductive connections. This prevents electrical paths between adjacent tabs caused by condensation, electrolyte leaks, or contamination.
9. Elastic Pouch Spacer with Insulating Coating for Battery Cell Damage Response
SK On Co., Ltd., 2023
Spacer for secondary battery cell insulation that prevents fires and explosions in batteries when cells are damaged or penetrated. The spacer contains an insulating coating liquid filled in an elastic pouch. When a cell is damaged, the pouch deforms and coating instantly forms an insulating film on the damaged area. If a foreign object penetrates, coating insulates the penetration site. The coating with insulating particles and binder absorbs cell swelling and improves stability. The elastic pouch also cushions cell expansion.
10. Battery Cell with Multi-Layer Insulating System on Outer Housing
NINGDE CONTEMPORARY AMPEREX TECH CO LTD, NINGDE CONTEMPORARY AMPEREX TECHNOLOGY CO LTD, 2023
Battery cell design with improved insulation to prevent electrical shorts and fires during thermal runaway. The battery cell has an insulating layer system that covers the outer surface of the cell housing. The insulating layers are adhered to the housing and also bonded to each other. This provides multiple layers of insulation that can withstand high temperatures and prevent electrical arcing between adjacent cells. The layers also have sufficient thickness to maintain insulation during thermal runaway. The layers can be made of materials like polyimide with high temperature resistance.
11. Battery with Insulating Member Featuring Large Pore Size Through-Hole for Enhanced Electrolyte Penetration and Short Circuit Prevention
Contemporary Amperex Technology Co., Limited, NINGDE AMPEREX TECHNOLOGY LTD, 2023
Battery design to prevent short circuiting and improve electrolyte penetration. The battery has an insulating member between the cells and outer housing. This prevents direct contact between cells and housing that could cause a short circuit. The insulating member has a large pore size (100-2000 microns) through-hole. When electrolyte is injected into the outer housing, it can pass through the hole to reach the cells. This allows thorough electrolyte penetration of the cell pole pieces for better contact and performance.
12. Battery Module with Rigid Cell Insulation and Expandable Terminal Insulation
LG ENERGY SOLUTION LTD, 2023
Battery module design to reduce fire and explosion risk in battery packs. The module has insulation between battery cells and between the cell terminals to block heat and particle propagation. The cell-to-cell insulation is a rigid pad. The terminal-to-terminal insulation is made of an expandable material that compresses when cold but expands when hot. This prevents gaps between cells and terminals from becoming air channels.
13. Battery Pack Housing with Integrated Protruding Insulation for Cell Stabilization
SUNWODA ELECTRIC VEHICLE CELL CO LTD, 2023
A battery pack design for electric vehicles that improves insulation between cells and reduces shifting of insulation parts during assembly. The design involves integrating insulation into the battery pack housing instead of using separate external insulation pieces. The insulation is attached to walls of the housing and protrudes between cells to maintain insulation. This eliminates the need for separate insulation parts that can shift during assembly and compromise insulation performance. The cells are secured to the housing walls to prevent movement.
14. Battery Pack with Insulator Sheets and Spacers for Electrical and Thermal Isolation and Venting Paths
RIVIAN IP HOLDINGS LLC, 2023
Battery pack design for electric vehicles that provides electrical and thermal isolation while allowing venting to prevent pressure buildup and cell-to-cell gas migration. The battery pack has insulator sheets between the battery cells and the pack enclosure for electrical isolation. Spacers bonded to the insulator sheets hold them away from the cells to provide venting paths between the cells and pack enclosure. This allows venting of gases from thermal events in individual cells without pushing them back into neighboring cells.
15. Battery Module with Bent Insulating Plates for Adjacent Cell Connection
Samsung SDI Co., Ltd., 2023
Battery module design and manufacturing method to insulate between battery cells without increasing module size. The module has adjacent battery cells connected by a bent insulating plate. The insulating plate is attached along the cell boundary and bent to connect both cells. This allows multiple cells to be easily insulated in a row without increasing module volume. The insulating plate can have extensions that wrap around adjacent cells and bend to connect them.
16. Battery Module Insulating Barrier with Jointed Board Structure for Cell Isolation
LONGHAI XIENENG NEW ENERGY TECH CO LTD, LONGHAI XIENENG NEW ENERGY TECHNOLOGY CO LTD, 2023
Insulating barrier for battery modules to prevent short circuits and improve safety by isolating adjacent battery cells. The barrier has a main insulating board with connected joints that sandwich between cells. This prevents deformation and contact of cell cases as they expand/contract during charge/discharge. The barrier is made of insulating flame-retardant material to reduce fire/explosion risks.
17. Battery Cell Arrangement with Insulating Paste Between Adjacent Cells
BYD Company Limited, BWD COMPANY LTD, 2023
Lightweight, compact and reliable battery design for electric vehicles that reduces weight, cost and complexity compared to conventional battery packs. The design involves connecting battery cells in series without separators between them. Instead, an insulating paste is applied between the facing surfaces of adjacent cells to prevent short circuits and ionic interactions. This allows omitting separators and reducing the number of structural members. The insulating paste also provides thermal insulation between cells.
18. Cell Module Design with Grooved End Face Insulators for Longitudinal Electrical Isolation of Round Battery Cells
AUDI AG, AUDI AKTIENGESELLSCHAFT, 2023
A method and cell module design to electrically insulate round battery cells in a cell module in a simple and efficient way. The cells have end faces that limit their longitudinal extension. The insulation involves inserting an insulator between the end faces of adjacent cells in their longitudinal direction. The insulator is positioned in grooves formed in the end faces of the cells. This allows the cells to be easily and efficiently isolated without requiring complex external insulation.
19. Assembled Battery with Insulating Coated Laminate Stack for Cell Displacement Prevention and Internal Resistance Reduction
APB CORP, 2022
An assembled battery design that prevents cell displacement and reduces internal resistance to improve battery life. The battery is made by stacking multiple cell laminates together and then enclosing them in an outer package. At least one side of the laminate stack is coated with an insulating material to cover the cell boundaries. This integrated insulator keeps the cell spacing consistent and prevents displacement during vibration or expansion. It also reduces internal resistance by preventing cell-to-cell contact that can form during motion or temperature changes.
20. Cylindrical Battery Cell and Stack with Radial Pole Alignment and Selective Dielectric Insulation
BAYERISCHE MOTOREN WERKE AG, BAYERISCHE MOTOREN WERKE AKTIENGESELLSCHAFT, 2022
Cylindrical battery cell, stack, and connector design for high-voltage battery packs in electric vehicles that improves electrical insulation while reducing pack size. The cells have inner and outer poles at different radii. The stacks have cells with aligned pole radii. The connectors have fixed widths to match. This allows tighter spacing between cells and stacks without risk of short circuits. A dielectric layer is applied over the cells and stacks, then selectively removed at specific points where the poles connect to the connectors. This provides full insulation around the cells and stacks, but allows direct contact at the poles for electrical connection.
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