374results about How to "Avoid thermal runaway" patented technology

The invention provides a lithium ion battery diaphragm and a high temperature thermal-stable lithium ion battery, which relate to lithium ion batteries. The diaphragm comprises a polyolefin microporous membrane which acts as a basic layer, wherein a nano ceramic material coating is manufactured on one side surface or two side surfaces of the polyolefin microporous membrane; and compositions of the nano ceramic material coating comprise any one of a zirconium oxide, an aluminum oxide, a silicon oxide, a titanium oxide, a silicon nitride, a boron nitride and an aluminum nitride or a combination of any oxide and any nitride, and additionally comprise binders. Since a high temperature resistant nano ceramic material is led into the surface of a conventional diaphragm, an insulating property better than the insulating property of the conventional diaphragm is provided, further internal insulating property damage brought by thermal contraction of the conventional diaphragm, which leads to thermal runaway of the lithium battery, is avoided particularly at high temperatures of 130 DEG C, 150 DEG C and 180 DEG C, and thereby the high temperature thermal stability of the lithium ion battery is improved and the safe reliability of the lithium ion battery is increased.

The invention relates to a novel ceramic coating polyolefin composite film which comprises a polyolefin substrate with micro pores, wherein one side or both sides of the polyolefin substrate is/are compounded with ceramic coating(s); the ceramic coating comprises porous ceramic particles, an inorganic filler and an adhesive. The invention also relates to a method for preparing the novel ceramic coating polyolefin composite film. The method comprises the following steps: a, dissolving the adhesive in a solvent, thereby preparing an adhesive solution; b, adding the porous ceramic particles and the functional inorganic filler into the adhesion solution prepared in the step a, and performing dispersing treatment, thereby preparing coating slurry; and c, coating one or two surfaces of the polyolefin substrate with the coating slurry prepared in the step b, and drying and curing to prepare the product. The novel functional composite film has high liquid absorption and retention performance, has the functions of reducing harmful gases inside a battery, improving the performance of the battery and prolonging the service life of the battery, and has the safety characteristics of low closed pore temperature, high melting temperature and low hot-shrinkage rate.

The invention relates to the technical field of battery charging, in particular to a charging method of a lithium ion battery based on time and temperature. Polarization voltage limited maximum charging current is calculated based on lithium ion battery polarization characteristics, and under the constraint of the maximum charging current, charging temperature rise and charging time are considered comprehensively, genetic algorithm is employed to search the optimal charging current so as to balance the mutual contradictory objects of reducing charging time and lowering charging temperature rise. The result shows that the optimal charging current ensures charging rapidity, at the same time controls the polarization voltage and temperature rise of the charging process within an allowable range, and guarantees the charging capacity, charging efficiency and charging safety and battery life.

The invention specifically relates to a high-voltage lithium ion battery electrolyte, which belongs to the technical field of lithium ion battery electrolytes. The high-voltage lithium ion battery electrolyte provided by the invention comprises a non-aqueous solvent, a lithium salt and an additive, wherein the additive comprises a mixture of a fluoro-ether additive and an alkyl dinitrile additive. A lithium ion battery using the high-voltage lithium ion battery electrolyte has stable cycle performance at normal temperature, no gas generation at a high temperature condition and small changes of internal resistance. A preparation process for the high-voltage lithium ion battery electrolyte is simple and easy to implement and has good market prospects.

The invention belongs to the technical field of power batteries, and especially relates to a power battery top cover and a power battery using the top cover. The power battery top cover comprises a top cover sheet, and a firs pole pillar, a second pole pillar, a pressure release valve, a liquid injection hole, pneumatic overturning sheets and a resistor block, the first pole pillar is in insulation connection with the top cover sheet, the second pole pillar is electrically connected with the top cover sheet through the resistor block, the pneumatic overturning sheets are electrically connected with the top cover sheet, the conductive block is arranged above the pneumatic overturning sheets, a baffle plate is arranged under the pressure release valve, the pneumatic overturning sheets comprise a first pneumatic overturning sheet and a second pneumatic overturning sheet, and the thickness of the first pneumatic overturning sheet is smaller than the thickness of the second pneumatic overturning sheet; and when the pressure in the power battery increases, the pneumatic overturning sheet and the second pneumatic overturning sheet sequentially move upward in order to electrically connect the first pole pillar with the second pole pillar. Compared with power battery top covers in the prior art, the power battery top cover disclosed in the invention makes the power battery have an excellent safety protection function in overcharging, nailing, short circuit and hot box test.

Disclosed is a charging machine including a main charging circuit and a charging control circuit, the main charging circuit comprises a filter circuit, a rectifier filter circuit, a pulse bleeder circuit, a half-bridge inversion circuit, a drive control circuit and a high frequency rectifier charging circuit, the charging control circuit comprises a power supply circuit, a voltage stabilizing circuit, a self-recycle circuit, a current detecting circuit, a voltage detecting circuit and a temperature detecting circuit, and the charging control circuit also comprises a control display circuit and a pulse modulation switching power supply integrating control circuit. The charging machine can effectively release the sulfation phenomenon of a battery plate by controlling a single chip microcomputer in the control display circuit to adopt multi-stage pulse type charging method, fives stages including constant current, constant voltage, floating charge I, average charge and floating charge II. Each stage in process outputs different duty cycle pulsing signal through the control of single chip microcomputer and then a half-bridge power tube is controlled to reach intermittent pulse current charge and depolarization effect.

The invention relates to a method for monitoring thermal runaway of a lithium ion battery of an electric vehicle. A voltage changing rate parameter when thermal runaway occurs in the lithium ion battery is monitored, and a battery voltage can be reduced abruptly, is maintained at a low voltage for 40-60 seconds and then is gradually raised to an initial voltage when the thermal runway occurs in the lithium ion battery; the fact that thermal runaway occurs in the battery can be judged by taking the battery voltage changing rate parameter as a monitoring object and is a first judgment method; abattery temperature rising rate changing parameter is monitored, the fact that thermal runaway occurs in the battery also can be judged when the battery temperature rising rate is larger than or equalto 10 DEG C per minute and is a second judgment method; and a battery management system (BMS) is used for monitoring, analyzing and judging the battery voltage changing parameter and the battery temperature rising rate parameter, the two methods are used as an independent condition or a logic combination condition and used as a technological basis for judgment on thermal runaway of the battery, and an early-warning signal can be given out in advance when thermal runaway occurs. By the method, the battery thermal runaway judgment time is greatly increased, and enough handling time is providedfor a person to escape and timely take a measure to prevent battery thermal runaway from being generated, propagating and being expanded.

The invention aims to solve the technical problem of fire or explosion of batteries and provides a high-safety lithium ion battery which can radically realize fire resistance and explosion prevention. The high-safety lithium ion battery comprises a positive pole piece, a diaphragm and a negative pole piece, wherein the diaphragm is positioned between the positive pole piece and the negative pole piece; the positive pole piece comprises a positive-pole current collector and positive pole pulp, and the positive pole pulp is coated on the positive-pole current collector; the negative pole piece comprises a negative-pole current collector and negative pole pulp, and the negative pole pulp is coated on the negative-pole current collector; and the positive pole pulp and/or the negative pole pulp comprises a conductive agent which is a high-polymer thermosensitive material with positive temperature coefficients. In the pole piece added with the high-polymer thermosensitive material with positive temperature coefficients, under uncommon conditions, when current or temperature rises sharply, the specific resistance follows to rise, thus a conductive network is destroyed, thermal runaway generated by batteries is prevented and a preventative effect is played on the thermal runaway of the lithium ion batteries. The invention greatly increases the safety performance of the lithium ion battery and can radically solve the safety problem of batteries.

A diaphragm is disclosed, which comprises a porous diaphragm substrate and a heat-sensitive coating coated on at least one surface of the diaphragm substrate, wherein the heat-sensitive coating comprises 10 to 90 wt.% of thermal expansion microspheres and 3 to 15 wt.% of an adhesive, and the thermal expansion microsphere comprises a blowing agent and a thermoplastic polymer shell encapsulating theblowing agent. Compared with the prior art, the diaphragm of the present invention can prevent the occurrence of thermal runaway of the battery and remarkably improve the safety of the lithium ion battery by coating the heat-sensitive coating containing thermal expansion microspheres on the surface of the diaphragm. In addition, the invention also discloses a preparation method of the diaphragm and a lithium ion battery using the diaphragm.

The invention discloses a method for charging a battery of an electric road vehicle. The method comprises the following steps of: (1) pre-charging; (2) A-period constant current charging; (3) B-period constant current charging; (4) constant voltage charging; (5) double-threshold charging; and (6) float charging, wherein the base number of the charging environment temperature is 25 DEG C, current and voltage in the whole charging process are adjusted in inverse proportion to the environment temperature, a current adjustment coefficient is 30 to 80 mA/DEG C, a voltage adjustment coefficient in the step (6) is 3 to 4 mV/monomer.DEG C, and a voltage adjustment coefficient in other steps is 5 to 6 mV/monomer.DEG C. By adjusting charging parameters under different temperature conditions, a charging effect of the battery at different temperatures is ensured, and the service life of the battery is prolonged.

The invention relates to a cylindrical battery. The cylindrical battery comprises a shell, a battery cell, a pole, a cover plate, a positive collector plate and a negative collector plate, the shell is of a cylindrical groove structure, and the battery cell, the positive collector plate and the negative collector plate are all arranged in the shell. The cover plate is connected with the notch of the shell. The pole is riveted with the shell, the pole penetrates into the shell from the bottom end face of the shell, and an insulating sealing piece is arranged between the pole and the shell. The battery cell is of a full-tab structure, the two end faces of the battery cell are connected with the positive collector plate and the negative collector plate respectively, the end, located in the shell, of the pole is electrically connected with the battery cell through the positive collector plate, and the shell is electrically connected with the negative collector plate. The invention also relates to a battery module. The battery module comprises the cylindrical battery. The invention also relates to a battery pack. The battery pack comprises the battery module.

The present invention relates to the technical field of secondary battery pack manufacturing, and provides a high specific energy battery pack internal flame-retardant cooling method. According to the method, a flame retardant agent is subjected to a microencapsulation treatment and the treated flame retardant agent is filled inside the battery pack, such that the problem that the sharp temperature change caused by the electrical core short circuit and other failures causes firing burning even explosion can be solved. According to the present invention, the method has the following effects that after the temperature in the battery pack is increased to a certain value, the shell of the microcapsule filled with the flame retardant agent is rapidly dissolved or broken to release the flame retardant agent, and oxygen is consumed or diluted through the physical pathway of the isolation film forming on the local high-temperature area and the surrounding in the battery pack and the chemical pathway of the free radical terminating so as to achieve the functions of flame retardant effect and cooling, terminate the spreading of the high temperature area, eliminate and reduce the firing risk, and improve the safety performance of the battery pack; and the method has advantages of high safety and high reliability, and with the microcapsule flame retardant agent, the installation of the larger fire extinguishing device is avoided, and the advantages of lightweight and environmental protection are provided.

The invention discloses a battery pack with a cooling device and further discloses a cooling method of the battery pack. The cooling method comprises the following steps: when the temperature of a battery cell in a shell rises, cooling fluid around the battery cell is immediately boiling and evaporated, and latent heat absorbed during evaporation can realize the cooling of the battery cell; the produced cooling fluid vapor is distributed in the inner chamber of the shell, such that the internal pressure of the inner chamber of the shell rises, partial cooling fluid in the inner chamber of the shell is condensed, the internal temperature of the shell rises and temperature corresponding to new vapor pressure is formed in the shell; when the temperature of the battery cell or a cooling part in the shell drops, the cooling fluid vapor around the battery cell or the cooling part is condensed to release latent heat and the condensation of the cooling fluid causes the pressure of the inner chamber of the shell to drop, such that partial cooling fluid is evaporated, the internal temperature of the shell drops and temperature corresponding to new vapor pressure is formed in the shell.

The invention belongs to the technical field of charging of a lithium ion battery, and particularly relates to an optimized charging method of a vehicle-mounted energy storage lithium ion battery for rail transit. The optimized charging method comprises the steps of calculating maximum charging current and a charging cutoff voltage of a lithium ion battery within a full-life period according to cycle lifetime attenuation characteristic of the lithium ion battery; constructing an optimized charging target function under the constraint of the maximum charging current and the charging cutoff voltage by taking charging time reduction and battery charging temperature rising control as targets; and seeking an optimal charging current by a genetic algorithm so as to balance the two conflict targets of charging time reduction and the charging temperature rising reduction. A result shows that the optimal charging current is used for ensuring charging rapidness and simultaneously controlling a polarization voltage and the temperature rising during the charging process to be within allowable ranges, and the charging capacity, the charging efficiency, the charging safety and the battery lifetime are ensured.

The invention relates to a preheating charging loss optimization battery pack charging method in the low-temperature environment and in particular relates to a battery pack charging method. The preheating charging loss optimization battery pack charging method aims to optimize energy consumption of preheating process of the charging process and energy loss of charging process of a battery pack in the low-temperature environment. The preheating charging loss optimization battery pack charging method is characterized by comprising the following steps: preheating the battery pack in the low-temperature environment, so that the charging performance of the battery pack is recovered, and determining preheating target temperature and battery pack constant current charging current by utilizing a modern data optimization algorithm, taking battery preheating target temperature and battery charging current as solving quantity and taking minimum energy consumption of preheating and charging processes as a target according to the charging current and the working temperature range provided by a battery manufacturer. By utilizing the preheating charging loss optimization battery pack charging method, the low temperature service ability of the battery pack can be effectively improved.

The invention provides a phase change composite, a preparation method and an application. The phase change composite is prepared from paraffin powder, expanded graphite powder, polyethylene particlesand SEBS. By adopting a material system in a special ratio, the defects that the conventional phase change energy storage material is low in thermal conductivity and required to be encapsulated in practical use to prevent leakage are overcome, thermal management efficiency is increased greatly, and popularization and application range of the phase change energy storage material is expanded.

The invention discloses a phenolic resin modified ceramic diaphragm and application thereof. The diaphragm comprises porous base film, at least one side of the film is provided with a phenolic resin ceramic layer by spreading a phenolic resin ceramic slurry; at least one surface of the porous base film is coated with the ceramic layer, and the surface of the ceramic layer, the insides of pores, the insides of the pores of the porous base film and the surface which is not coated with the ceramic layer are immersed in a phenolic resin precursor solution to be subjected to the in-situ polymerization to form the phenolic resin layer. Through the mixing coating of the phenolic resin and the ceramic slurry or the in-situ polymerizing of the phenolic resin on the basis of the ceramic diaphragm, aphenolic resin ceramic mixed layer can be formed on the surface of the porous base film, the surface of the porous base film and the insides of the pores are coated with the in-situ coating phenolicresin layer, thereby improving the thermal stability of the diaphragm, the diaphragm does not shrink at 200 DEG C and still maintains strong mechanical strength, the contact of the positive and negative electrodes is effectively blocked, and the safety performance of a battery is ensured.

The invention provides a microcapsule, comprising a capsule shell portion and a capsule core portion that is selected from one or both of an organic flame retardant and an inorganic flame retardant, wherein the outer surface of the capsule shell portion has a pile structure, and the capsule shell portion is made of polymer material. The application also provides a method of preparing the microcapsule, and a lithium ion battery. The microcapsule provided by the application is applied to the lithium ion battery, which can improve the safety of the lithium ion battery without affecting the electrochemical performance of the lithium ion battery.

The invention relates to the field of battery energy storage system security, in particular to the field of power battery security. An emergency refrigerating device for a battery energy storage system adopts liquid nitrogen phase-change refrigeration, and comprises a nitrogen generator, a liquid nitrogen container, a cooling pipe, a cooling valve, refrigerating passages and a pressure release valve. The nitrogen generator is used for nitrogen generation and cooling storage during battery charging. A rechargeable micro battery supplies power for the cooling valve, and the controller is provided with an independent signal collecting and logic processing mechanism without depending on a battery management system (BMS); and the controller comprises a vibration sensor which can sense the accidents such as collision and explosion. A closed refrigerating passage is generally mounted on a heat-dissipation module of the battery, and the heat of the battery is dissipated through the heat-dissipation module. An open refrigerating passage is mounted on the battery, and a plurality of small holes formed in the part, close to the battery, of the pipeline are used for uniformly spraying liquid nitrogen onto the battery. The emergency refrigerating device has the beneficial effects that the liquid nitrogen is used for emergency refrigeration, and can reach the effect of quick cooling, so that thermal runaway of a battery pack is prevented, and a thermal runaway chain reaction is avoided to the maximum extent.

The invention discloses a water-based conducting sizing agent for coating on the surface of the current collector of a high-safety lithium battery. The water-based conducing sizing agent is prepared from the following components in percentages by weight: 0.5% to 15% of a conducting material, 0.5% to 10% of a dispersing agent, 0.2% to 2% of cellulose, 0.1% to 1% of a wetting agent, 2% to 20% of an adhesive, 0.5% to 10% of a polyolefin microballoon emulsion and the balance of deionized water. The invention also discloses a preparation method of the water-based conducting sizing agent and a method for using the water-based conducting sizing agent on the current collector of the high-safety lithium battery. According to the water-based conducting sizing agent disclosed by the invention, thermal runaway can be effectively prevented, so that the safety of the battery is improved; the adhesive force between a positive material and an aluminum foil and the adhesive force between a negative material and a copper foil are improved, and the proportion of the positive adhesive or the negative adhesive is reduced, so that the energy density of the battery is improved, and the endurance mileage is increased; simultaneously, the internal resistance of the battery is greatly reduced, dynamic internal resistance consistency of the battery is improved, and the service life of the battery pack is prolonged; the electrical conductivity of the positive material and the aluminum foil and the electrical conductivity of the negative material and the copper foil are strengthened, and the charging capacity and discharging capacity are quickly improved.