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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A separator for lithium-ion batteries that provides high capacity and safety. The separator has a unique composition and structure to balance capacity improvement with thermal and mechanical stability. It uses a polyolefin-based microporous substrate coated with a heat-resistant layer containing inorganic particles and a binder. The total separator thickness is 10-40 µm. The heat-resistant layer thickness is 90% of the substrate thickness. This design provides heat resistance, mechanical strength, and capacity retention compared to conventional separators.

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A heat-resistant battery separator with improved integrity and shutdown capability for lithium-ion batteries. The separator has three layers: two microporous layers sandwiched between a heat-resistant layer. This configuration provides separation and integrity at high temperatures during thermal runaway. The heat-resistant layer can be made of a high melt integrity material like polyaramid, polyimide, or polyamideimide. The microporous layers can have functional groups on their surfaces that increase adhesion to the heat-resistant layer. This prevents curling and delamination during thermal runaway.

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Battery module design to mitigate thermal runaway propagation between cells. The module has a heat sink in contact with the cells to absorb thermal energy. If a cell exceeds a runaway threshold, a switch detects it and transfers thermal energy from the runaway cell to the module housing to control propagation. This prevents adjacent cells from overheating and stopping runaway from spreading.

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Flame-retardant composite separator for lithium-ion batteries that reduces the risk of thermal runaway. The separator has a base film and a coating containing low-melting-point polymers, nanofiber flame retardants, paraffin microspheres, thickening agent, and binder. The low-melting-point polymers lower the closed pore temperature to prevent ion transmission and reaction escalation. The nanofiber flame retardants release after melting to reduce temperature rise. The paraffin microspheres have a lower melting point than the base film, delaying closed pore formation. The thickening agent prevents separation. The binder holds the coating together.

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A high-performance high-power module control system for electric vehicles that provides improved safety, temperature management, and monitoring capabilities. The system uses a combination of specialized modules connected by PCBs to control and protect the battery modules. The safety protection module monitors system health and cuts power in case of short circuits. Overcurrent, overcharge, and overdischarge protection modules prevent battery damage. A fusing module blows fuses if needed. A smoke detection module alerts to hazards. Temperature monitoring, cooling, and heating modules manage temperatures. The PCB control module integrates and manages these modules.

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An anti-overcharge, temperature-controllable and high-protection lithium battery pack system for magnetic levitation trains. The system has a battery management module that monitors cell voltages during charging. If a cell exceeds a threshold voltage, the module closes a switch to connect a consumption resistor. This reduces current to prevent overcharging. It also adds temperature control to mitigate thermal runaway risk.

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Lithium ion battery diaphragm with improved short circuit prevention and fire resistance compared to conventional diaphragms. The diaphragm has a base film sandwiched between reinforcing structures on both sides. The reinforcing structures include ceramic coatings, fire retardant layers, and air bags filled with flame retardant foaming agents. The reinforced diaphragm prevents electrode particle penetration through micropores while also blocking short circuits. The fire retardant layers and foaming agents prevent flame propagation in case of thermal runaway.

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Fire prevention system for lithium-ion batteries that uses deformation elements to detect abnormal cell heating, unlock coolant channels, and directly spray coolant onto hot cells to prevent thermal runaway and propagation. The system leverages indirect contact cooling during normal operation, but switches to direct contact when deformation elements detect overheating. This allows rapid quenching of hot cells by boiling coolant contact to prevent runaway and fire spread. The coolant discharge stops when the cell cools, draining the module.

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Battery diaphragm with improved flame retardant properties to enhance battery safety. The diaphragm has multiple layers stacked between the positive and negative electrodes. The topmost layer is a fire-retardant layer made of nano ceramic powder. This layer melts at high temperatures and seals off the diaphragm to prevent ion conduction and short circuits. Below it are layers of regular diaphragm material to allow ion transfer. The bottom layer is the electrode. This multi-layer configuration provides ion conduction, separates the electrodes, and adds fire retardancy.

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Lithium-ion battery module with thermal runaway blocking capability to prevent spread of thermal runaway between cells. The module has features like air cooling channels between cells, rubber blocks, and a melting paraffin block between cells. This isolates a cell experiencing thermal runaway and prevents heat spread. The bottom plate has openings for erupting gases to exit and an exhaust fan. Increased airflow cools the cell and prevents runaway spread. The monitoring detects violent temperature and voltage fluctuations to trigger the blocking mode.

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Flame-retardant diaphragm for lithium-ion batteries that reduces ignition and explosion risk during thermal runaway. The diaphragm contains an inorganic flame retardant called ammonium aluminum carbonate (AAC) that coats the separator between the battery's positive and negative electrodes. The AAC prevents ignition and explosion when the battery overheats by forming a protective barrier that absorbs heat and inhibits combustion reactions. This improves battery safety without complex preparation or material substitutions.

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Flame-retardant composite diaphragm for lithium-ion batteries that improves safety without degrading performance. The diaphragm has a flame-retardant coating with a double-layer microcapsule. The inner layer has a flame retardant and melts at higher temps. The outer layer melts at lower temps to seal the diaphragm. This prevents battery shorting at low temps, then releases flame retardant at high temps to prevent thermal runaway. The double-layer microcapsule provides dual effects of closed pores and flame retardance without adverse battery impacts.

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Multi-layer composite functional separator for lithium-ion batteries with improved safety and thermal stability compared to conventional separators. The separator has four layers: a base layer, an insulating layer, an expanding layer, and a shrinkage layer. The layers are stacked in a specific order. The base layer provides mechanical support. The insulating layer prevents short circuits. The expanding layer has microspheres that expand with temperature to reduce current density. The shrinkage layer shrinks less than conventional separators to prevent contact during thermal runaway. The multi-layer structure improves safety and thermal stability of lithium-ion batteries.

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Flame retardant separator for lithium batteries that prevents thermal runaway and improves safety while maintaining battery performance. The separator has an asymmetric coating structure with a flame retardant layer only on the positive electrode side. The coating layers are a hydroxide-based flame retardant on the positive side and a binder or inorganic particles on the negative side. This asymmetric coating prevents lithium precipitation on the negative side from reacting with moisture generated by the flame retardant on the positive side. The separator allows flame retardant effectiveness without compromising battery cycle life or electrolyte impregnation compared to fully coated separators.

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A separator for lithium-ion batteries that provides improved fire resistance and prevents shrinkage of the separator during battery operation. The separator has a flame retardant layer sandwiched between the porous substrate and the coating layer. This provides fire protection to the separator without adding excessive flame retardant to the coating layer, which could degrade performance. The flame retardant layer directly shields the substrate from fire, preventing shrinkage. The coating layer with the inorganic material still enhances separator properties like electrolyte wettability.

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Explosion-proof rechargeable battery and protection system that can improve battery energy efficiency, prevent thermal runaway, and suppress fires. The system uses a sealed housing filled with an insulating/conductive liquid to surround and immerse the battery and electronics. This prevents leaks, improves thermal management, and prevents arc ignition. The liquid temperature is regulated to avoid overheating. It aims to eliminate sources of battery failure and improve performance by maintaining optimal operating conditions.

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A separator for lithium-ion and lithium metal batteries that addresses the issues of dendrite formation, short circuiting, and electrolyte consumption in lithium metal batteries. The separator is a composite material that combines an elastic polymer with a flame retardant. The composite has high elasticity, allowing it to conform to the anode and cathode surfaces. This provides good contact and prevents separation. The composite also contains a lithium ion conductor to enable ion transport. The elasticity, flame retardancy, and ion conductivity of the composite separator replace the need for separate anode protection and separator layers in lithium metal batteries.

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Lithium ion battery diaphragm with improved safety and thermal stability for lithium ion batteries. The diaphragm has multiple layers to prevent short circuits and improve thermal stability. The layers are: 1. A separator base made of a polyolefin like polyethylene. 2. An inorganic nanoparticle layer directly on the separator base. 3. A high-temperature resistant polymer layer on top of the nanoparticle layer. 4. Two flame-retardant layers on the outside. The layers provide structural strength, thermal stability, and flammability reduction. The nanoparticles prevent short circuits, the high-temp polymer prevents thermal shrinkage, and the flame-retardant layers reduce flammability.

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Explosion-proof rechargeable battery and protection system that improves battery energy efficiency, prevents thermal runaway, and reduces fire risk. The battery is enclosed in a housing filled with an insulating and heat conducting liquid. The battery module and electronics are immersed in the liquid. This provides insulation, heat dissipation, arc suppression, and temperature regulation to prevent thermal runaway and fires. The liquid also stops leaks and arcing. An internal heating module regulates the liquid temperature for optimal charging/discharging.

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A protection board for 36V lithium battery packs used in balance cars and electric scooters to prevent charging hazards. The protection board continuously monitors the battery state during charging and discharging to detect issues like overcharging, overdischarging, short circuits, and overcurrent. It provides real-time battery health feedback and shuts down the pack if problems are detected to prevent heating, burning, and other safety hazards.

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Lithium battery with a built-in alarm for power failure to improve safety and prevent damage. The battery has a protective shell with a warning device, voltage monitor, and sealing ring. Inside the shell is the battery cell, insulating layer, moisture-proof layer, explosion-proof layer, and flame-retardant layer. The cell has a heat sink at the bottom. An alarm module is attached to the cell end. When the voltage gets too high, the alarm device sounds to alert of overcharge. This prevents damage from excessive discharge.

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Composite phase change endothermic temperature control battery module structure to prevent spontaneous combustion. The module has a sealed housing filled with a low-melting composite phase change material that coats the battery cells inside. This absorbs heat from cells experiencing thermal runaway to mitigate temperature rise. A temperature sensor in the housing detects abnormal cell temperatures. External cooling is also provided. This prevents cell faults from spreading and mitigates thermal runaway chain reactions.

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A battery safety device for power batteries that provides thermal management and fire control at the cell and module level. The device has three components: a trigger assembly between cells, a thermal energy assembly inside cells, and a fire extinguishing assembly inside the module. The trigger assembly uses a heat-sensitive composition with a flame retardant that melts to close a circuit and activate the thermal energy component. The thermal assembly contains phase change material that softens and releases fire retardant at high temperatures. The fire extinguisher has microcapsules with temperature-sensitive shells filled with fire suppressants. This integrated safety system prevents thermal runaway propagation and battery fires by isolating, cooling, and extinguishing localized failures.

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Composite diaphragm for lithium-ion batteries that provides improved fire safety. The diaphragm has a base film, ceramic layer, and fire-retardant insulating layer on the opposite side of the base film. The insulating layer contains ammonium polyphosphate particles. When heated, the ammonium polyphosphate decomposes into nitrogen, water, and a compact polymeric acid layer. This dilutes combustible gases, isolates combustible materials, and carbonizes them to prevent violent fires. The insulating layer acts as a barrier and converts rapid combustion into a mild, long exothermic reaction to protect the battery from fire.

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Protection board for a 12V lithium battery pack management system that provides features like overcharge protection, overdischarge protection, and discharge protection to enhance safety of lithium batteries. The board uses a lithium battery protection chip connected to modules for charge-discharge control, temperature detection, and equalization. The chip detects battery conditions like voltage and current to implement protection functions like preventing overcharge, overdischarge, and short circuits. The temperature module has a thermistor to monitor battery temperature.

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A separator for lithium secondary batteries that improves safety and thermal stability by using flame-retardant particles in the separator coating. The separator has a porous polymer substrate with a coating layer on at least one surface. The coating contains a high heat-resistant binder polymer like PVP and a large amount of flame-retardant particles like aluminum hydroxide or boehmite. This composition reduces thermal contraction and improves mechanical safety compared to regular separators. The separator thickness can be reduced to increase battery energy density.

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Functional diaphragm with safety performance for lithium-ion batteries. The diaphragm has a base film made of a high-melting-point material like PET, PI, or aramid. A low-melting-point material like polyethylene or EVA is coated on the base film using extrusion coating. The low-melting-point coating prevents contact between the battery electrodes at low temperatures, while the high-melting-point base prevents deformation and rupture at high temperatures. The coated diaphragm provides improved safety by preventing short circuits and thermal runaway at both low and high temperatures compared to regular diaphragms.

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Power battery module design to improve safety and reduce damage during thermal runaway of individual cells in the module. The module has a ventilation duct above the cells with a temperature sensor and coolant spray device. When a cell's pressure relief valve opens during runaway, the ventilation duct captures the flue gas and coolant sprays only on the affected cell. This prevents unnecessary cooling of good cells and improves localized thermal quenching compared to flooding the whole pack.

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Battery protection system for electric mopeds to prevent battery overcharging, overdischarging, and short circuits. It provides multiple layers of protection during charging and discharging. The system uses an analog front-end chip, secondary protection chip, and current-limiting fuse. The analog front-end chip monitors battery voltage and current. The secondary protection chip further checks for overvoltage or disconnection. If so, it cuts off the three-terminal fuse. This provides additional protection beyond just the fuse or MOS tube in existing systems. The fuse provides an extra line of defense against excessive charging current.

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Diaphragm for lithium-ion batteries that reduces explosion risk without increasing electrolyte viscosity. The diaphragm has a coating of porous carbon material and a polymer encapsulating it. The polymer melts or flows at a temperature lower than the separator's failure point. When battery temperature rises, the polymer softens and exposes the porous carbon. This adsorbs decomposing electrolyte gas, preventing explosions. The separator improves safety without degrading battery performance compared to adding flame retardants to the electrolyte.

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