Materials for Increasing EV Battery Safety

A secondary battery with improved safety and widened hot box temperature window. The battery has a separator with organic coatings on the sides facing the electrodes. The coating on the positive side contains a polymer with a melting point of 60-100°C. This low-melting polymer provides good adhesion at normal temperatures but separates at high temperatures to prevent heat accumulation and thermal runaway. It widens the safe operating temperature range without affecting cycle performance.

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A protection device for lithium batteries used in explosive environments like coal mines to mitigate the risks of thermal runaway. The device has active cooling to delay and suppress thermal runaway reactions. It also has a pressure relief mechanism to vent gas and prevent explosions. The cooling and venting features are inside a sealed flameproof shell that prevents sparks and flammable gases from escaping. The shell has bursting discs, explosion relief structures, and transfer barriers to manage pressure and impurities. The cooling and venting help protect the battery from thermal runaway without redesigning the battery itself, unlike prior art.

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A battery cell design to prevent thermal runaway propagation in lithium-ion batteries. The cell has an electrode stack with separators made from materials like polypropylene and polyethylene. To prevent thermal runaway between electrodes, the separator material can contain powdered flame retardant. Additionally, the anode can be coated with a carbon layer containing aluminum oxide particles to support lithium storage and prevent dendrite growth. These modifications aim to prevent thermal runaway spreading from one electrode to the next in the event of an overheating or failure condition.

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Lithium-ion battery with integrated fire suppression for improved safety in applications like electric vehicles, port drives, and marine vessels. The battery enclosure is filled with a fire suppressant instead of vacuum or air. It also has terminals for releasing gases, adding/removing fire suppressant, and electrolyte. This allows the suppressant to fully surround and cool the cells during overheating or short circuiting, preventing runaway reaction and combustion. The enclosure seals prevent gas escape and suppressant leakage. The battery can still operate normally in normal conditions. The enclosure and terminals enable integrated fire suppression without external systems or pumped agents.

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Lithium-ion battery separator with improved safety and electrochemical performance. The separator is a single-layer film made of a high molecular polymer and a nitrogen-phosphorus flame retardant. The separator has excellent heat stability, flame retardance, and electrolyte wettability. The flame retardant content is 10-50 wt% of the separator. The separator can be prepared by dissolving the polymer, flame retardant, and pore former in a solvent, casting, and drying.

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Battery module design to prevent thermal runaway propagation between cells. The module has cooling channels between battery cells that can be filled with fire suppressant if a cell temperature exceeds a threshold. The cooling channels are formed by protrusions on inner and outer panels that support each other. This allows filling the channels with suppressant to extinguish runaway in one cell and prevent spread to adjacent cells. The channels are also interconnected and inclined to enable effective filling.

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A power battery, thermal management cycle control system, and method to improve battery thermal management and thermal safety protection. The battery has upper and lower liquid cooling assemblies for normal operation. In case of thermal runaway, a thermal runaway suppression pipeline in the upper assembly can be fused and coolant sprayed to quickly suppress the failure. The system uses a battery management system (BMS) to monitor temperature and a vehicle control unit (VCU) to manage pumps and valves. This allows active cooling of out-of-control cells during thermal runaway events.

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Separators for lithium-ion batteries with fire suppression capability to prevent thermal runaway propagation. The separator has a microporous polymer layer sandwiched between the battery electrodes. Crosslinked cyclophosphazene particles are deposited on one or both sides of the microporous layer. These particles quench and inhibit combustion chain reactions when exposed to high temperatures.

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A separator for secondary batteries that reduces the risk of thermal runaway and explosion. The separator has a base film coated with a flame-retardant layer. The flame-retardant layer contains capsules with a core of flame retardant material like phosphorus compounds encapsulated in PMMA shells. The PMMA shell provides adhesion and prevents direct contact between the flame retardant and electrolyte during normal battery operation. If thermal runaway occurs, the PMMA shell breaks releasing the flame retardant to capture combustion free radicals and prevent further spread of fire.

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Flame-retardant diaphragm for lithium batteries, solid electrolyte interface layer, and battery to improve safety and performance of lithium metal batteries. The diaphragm has a flame retardant layer containing aluminum diethylphosphinate. During charging/discharging, it forms a solid electrolyte interface layer on the negative electrode that contains aluminum-containing inorganic salts, phosphorus-containing inorganic salts, and lithium aluminum alloy. This layer passivates the reactive lithium metal, prevents dendrite growth, and enhances cycle life compared to organic electrolytes. The aluminum phosphinate diaphragm also acts as a flame retardant to mitigate lithium metal battery fires.

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Separator for lithium-ion batteries with fire suppression capability to prevent battery cell thermal runaway and propagation. The separator has a microporous layer sandwiched between the electrodes, with fire suppression layers on one or both sides. The fire suppression layers contain a ceramic with interconnected pores filled with a cyclophosphazene compound. The cyclophosphazene quenches and inhibits combustion chain reactions when exposed to high temperatures, preventing thermal runaway propagation in case of battery cell failures.

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Secondary battery with improved thermal safety by using a separator with a coating on the base film that melts at high temperatures to seal the separator pores and prevent thermal runaway. The coating density, base film porosity, and thickness are controlled to balance pore closing at high temperatures with normal battery operation. The coating melts at 90°C or above, has a density of 0.9-1.05 g/cm3, the base film has 20-50% porosity, and thickness of 3-10 μm. This allows the coating to seal the base film pores at high temperatures to prevent thermal runaway.

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Passenger car battery system with built-in safety features to prevent thermal runaway and improve safety and stability. The system uses a liquid cooling system, sealing rings, pressure relief valve, and protective covers to contain and dissipate heat. It also has a battery management unit (BMS) connected to a central battery control unit (BMU) and a high-voltage distribution box (BDU) for monitoring and control. The liquid cooling pipes are connected between the battery units and a main pipe to extract heat. The system design aims to prevent thermal runaway spread and damage inside the battery pack and vehicle.

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A flame-resistant polymer composite separator for lithium batteries that prevents dendrite formation and reactions between lithium metal and the electrolyte. The separator has a porous layer of a flame-resistant polymer with pores filled by a second polymer. The first polymer has high ionic conductivity and flame resistance. The second polymer fills the pores and provides electrical continuity. This separator eliminates dendrite growth by allowing lithium ion transport through the porous layer and prevents electrolyte reactions with lithium metal by isolating the metal surface.

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Fire and explosion prevention device for electric batteries that can block flame leakage and discharge pressure generated during thermal runaway to prevent fires from spreading. The device consists of a ceramic vessel inside the battery pack that accommodates multiple battery cells. The ceramic vessel has pores to block flames and disperse pressure. Exhaust ports in the pack case vent internal gas pressure. Sensors detect impacts and temperatures to identify battery damage and inject insulating oil into damaged modules. A constant temperature maintenance system links to sensors to keep vessel/case temps appropriate.

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Heat-resistant flame-retardant composite battery separator that improves safety and cycle life of lithium-ion batteries. The separator has a base microporous polyolefin layer, inorganic particles, a binder, and a flame retardant. The inorganic particles and binder coat the base layer. The inorganic particles improve thermal stability and flame resistance. The binder adheres the particles to the base. The composite separator provides better heat resistance, flame retardance, mechanical strength, and electrolyte retention compared to conventional separators.

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Battery separator with optimized coating layers to improve hot box test passing rate and normal battery performance. The separator has a first coating layer with two polymers of different melting points. The lower melting point polymer disperses around the higher melting point polymer to prevent pore blocking during battery preparation and usage. This balances cohesion for hot box containment with gas permeability. The adhesion between coating layers is adjusted to open interfaces during heat generation while preventing deformation during charge/discharge. The coating thickness and particle sizes are optimized for adhesion, gas permeability, and cohesion. The weight ratios of the polymers balance hot box performance with normal battery adhesion.

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Explosion-proof lithium battery for automobiles that can quickly suppress and contain internal cell failures to prevent chain reactions and explosions. The battery has multiple explosion-proof boxes, each containing a lithium cell. If a cell overheats or shorts, a controller detects the issue and activates a high-pressure water pump to spray cooling water into the affected box. If cooling fails, an external fire truck can connect to a fire connection. The dispersed box design prevents cell failures from spreading.

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High-safety heat-absorbing flame-retardant diaphragm for lithium ion batteries that can balance safety and electrochemical performance. The diaphragm is made by coaxial electrospinning of polymer fibers with a core-shell structure. The core has a heat-absorbing flame-retardant layer containing a heat absorber, flame retardant, drying agent, and low-melting-point polymers. The outer protective layer is made of high-melting-point polymers. This design allows the diaphragm to absorb heat and prevent flaming when the battery overheats. The inner heat-absorbing layer uses materials like basic carbonates that absorb heat and release water. This prevents battery degradation from excessive moisture. The outer protective layer stops combustion by melting at high temperatures.

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Integrated fire suppression system for battery packs using existing cooling channels to deliver suppressant during thermal runaway. The system has a suppression module with a suppressant, which takes over cooling channel passages during failures. The suppressant pressure ruptures channel apertures to deliver suppressant at the failure site. This leverages existing channels for targeted suppression without extra piping. The system can also have dedicated suppressant channels with perforations for uniform suppression.

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