EV Battery Weight Reduction Strategies

A lightweight battery pack case that reduces weight and maintains compression force over time while restraining a stack of batteries. The case uses panel structure walls made of two metal plates with a lower density interposed member between them. The metal plates provide strength and the low density interposed member reduces weight. The panel structure walls press the battery stack from opposing sides to compress and restrain it.

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Battery lower casing for battery systems that balances weight reduction and cost while maintaining safety. The casing has a lightweight support frame with fixing beams connected to a bottom plate. The frame surrounds the battery modules and has fixing portions to connect to them. A gap between the bottom plate and modules absorbs impacts.

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Battery enclosure for electric and hybrid vehicles made of thermoplastic composites. The enclosure consists of a top panel with reinforcement ribs and crossbeams, a bottom panel with support ribs, and outer covers. The panels are molded from fiber-reinforced thermoplastic sheets while the ribs and crossbeams are injection molded onto the sheets. The parts are joined by over-molding. The thermoplastic composite enclosure reduces weight compared to metal enclosures while maintaining strength, and simplifies manufacturing by using fewer parts.

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A vehicle battery system that enables use of lithium-ion batteries in electric vehicles instead of heavy lead-acid batteries without requiring an auxiliary battery for system startup. The system uses two removable lithium-ion battery subassemblies connected in series via an interrupter with current-limiting and non-current-limiting paths. The first subassembly initiates precharge through the current-limited path to safely power up the system controller. The controller then closes the non-current-limited path to fully energize the system from both subassemblies. This allows the lithium-ion batteries to provide startup power without overloading.

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A bus bar module for a battery pack that reduces size and height while not obstructing gas release from the battery cells. The module has a thermistor attachment portion that positions the thermistor vertically within the module. The temperature sensing wire from the thermistor is routed perpendicular to the thermistor attachment direction. This avoids wire bulkiness and protrusions above the battery cells.

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Vehicle drive system using a motor for cruising, a battery pack, and an inverter, with the battery pack having two batteries serially connected and grounded at the connection point. The inverter output voltage is set higher than the battery voltages. This allows increasing motor output while reducing battery pack voltage to keep weight/cost low, by balancing the battery voltages through serial connection and grounding. It prevents torque fluctuations from battery voltage variations that could impair driving comfort. The batteries are removable cartridges for flexibility.

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A lightweight EV battery module with containing battery cells, a frame, a busbar frame, and an end plate that covers the busbar frame. The end plate consists of an insulating portion in contact with the busbar frame and a reinforcing portion inserted into the insulating portion. This maintains weldability and rigidity while reducing weight.

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Battery module for electric vehicles includes a cooling duct for cooling the battery stack and an exhaust duct for removing any gas emitted by the battery. The exhaust duct is contained inside the cooling duct, reducing space requirements compared to having separate ducts. This allows more compact battery modules for electric vehicles.

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Battery pack arrangement structure for an electric vehicle that enhances side collision resistance without increasing weight. The battery pack is housed in a metal die-cast case with an integral cross member that fixes to the vehicle frame. The case protrudes upward toward the vehicle floor to provide a crush zone for side impacts. A recess in the cover allows overlap with the floor cross member. This design avoids extra components while increasing the collision resistance of the battery pack.

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Optimizing the design of battery packs for electric vehicles that house cell stacks within irregularly shaped enclosures, to enable easier insertion of compressed cells into this opening and compression of cells between the irregular surfaces. It involves a block insert that interfaces between the irregular enclosure and cell stack. This insert allows compressing the cells to fit through the opening by providing a flat interface while transferring compression loads from the enclosure walls to the cells through a curved interface.

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Battery box design for electric vehicles that reduces space requirements by integrating key components and connectors. The box has a current interrupter, connector, and switch fixed inside the box body. The connector extends out through an opening to connect to external devices. The switch controls the connection between the batteries and the connector. This compact design allows the key components to be arranged efficiently inside the box, reducing size and cost compared to traditional designs with separate connectors.

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Vehicle battery pack design with higher energy density and simplified structure by applying a prismatic cell terminal exposure technique to pouch cells. The battery pack integrates functions to reduce parts and maximize cell volume. The cells have exposed terminals like prismatic cells. This allows direct busbar connection without intermediate modules. The pack has a cover pressing against the cells to prevent swelling. The cover also provides rigidity, cooling, and insulation functions. The battery pack has upper and lower casings, wiring, sensors, and a cell array in between. This provides a cell-to-pack (CTP) structure with simplified assembly compared to separate modules and cells.

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Traction battery packs for electric vehicles that include cell-to-pack battery systems. The battery packs have cell row separators that structurally couple adjacent cell stacks together. This allows the battery cells to be compressed prior to insertion into the pack enclosure. The separators are attached to the cell stacks using adhesive or tape.

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Electrochemical cells with thin metal foil packaging that is more efficiently designed and produced than in previous conventional pouch cells. The metal foil packaging fully surrounds the cell stack and is directly welded along its edges to form a hermetic or near hermetic seal. The metal foil packaging also functions as current collector, with one electrode bonded to it. The thin, compact metal packaging allows more space for the cell components compared to conventional pouch cells, improving energy density in small batteries. The metal-to-metal seal close to the stack reduces thickness and enables thin cells.

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A method of manufacturing a battery module for electric vehicles that is lightweight and has enhanced quality and durability. The method involves forming electrode leads by friction-welding together a copper piece and an aluminum piece, rather than using solid copper or aluminum leads. The aluminum exposed on the outside of the cell pouch allows improved soldering and reduces corrosion. The copper-aluminum leads also reduce weight compared to solid copper leads. The module is built by stacking pouch cells with exposed aluminum leads and connecting those together.

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Operating a high-voltage on-board power system of a motor vehicle with a fuel cell and a high-voltage battery. The method involves directly connecting the fuel cell to the inverter of the traction system without a voltage converter by first adjusting the high-voltage battery voltage to match the fuel cell voltage. This allows the fuel cell to be connected directly without a converter once the voltages are aligned. By avoiding a second converter, the power system can be more compact and efficient.

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Battery heating system for electric vehicles that reduces weight, cost, and complexity compared to conventional systems. The system uses a three-way valve to connect the engine coolant circuit and the battery coolant circuit. By mixing the coolants together, the engine coolant can provide heat to the battery circuit for heating the battery, without requiring a separate heat exchanger.

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A lightweight, efficient battery system for vehicles like aircraft that uses negative pressure inside the battery housing to tightly brace the cell block against the housing walls. The system uses a vacuum pump to generate negative pressure inside the sealed battery housing. The housing walls are flexible enough to be pulled inwards by the negative pressure and tightly brace the cell block. This provides stability while reducing weight compared to fill materials. The cell block can be insulated and the housing walls contact it directly.

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A method and system to semi-activate battery cells to improve performance. The method compresses a cylindrical battery cell using a buffer material and applies heat. The compression mechanism decreases the volume around the cell. The semi-rigid buffer material uniformly distributes pressure to the cell. Heating while compressed activates the cell. The compression and heating process enhances cell performance. The compression mechanism can be disengaged after heating.

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