27results about How to "Improve low temperature discharge performance" patented technology

The invention provides positive electrode slurry, a positive electrode plate, a lithium ion battery and a power utilization device, a positive electrode lithium supplement agent comprises a lithium iron phosphate main material, a binder, a conductive agent and a porous additive, the conductive agent comprises conductive carbon black with a high specific surface area, and the specific surface area of the conductive carbon black is greater than or equal to 130 m < 2 > / g. The space between the lithium iron phosphate particles in the positive electrode slurry provided by the invention is filled with the porous additive with the medium aperture and the conductive carbon black with the small aperture and the high specific surface area, so that a positive electrode plate applying the positive electrode slurry not only is small in internal pore spacing, but also forms gradient pore structure matching capable of reducing tortuosity of lithium ion transmission, and the lithium ion transmission efficiency is improved. And the technical effects of improving the electrolyte wettability of the electrode, improving the quick charge capacity, the cycle life, the low-temperature discharge capacity and the like of the battery are achieved.

The invention provides a secondary battery. The secondary battery comprises a negative pole piece and an electrolyte, the negative pole piece comprises a silicon-based negative pole material; the electrolyte comprises a first additive and a second additive; the first additive comprises fluoroethylene carbonate; and the second additive comprises a compound as shown in formula I: # imgabs0 #. The secondary battery disclosed by the invention adopts a silicon-based negative electrode material and has a compact and stable interfacial film, so that the side reaction of the battery is reduced, and the normal-temperature cycle performance, the high-temperature cycle performance, the high-temperature storage performance and the low-temperature discharge performance of the battery are improved.

The invention belongs to the technical field of batteries, and particularly discloses an electrolyte, a battery and an electric device, the electrolyte comprises a solvent, an electrolyte salt and a first additive, the first additive comprises silicon difluorophosphate as shown in a formula 1 and silicon borate as shown in a formula 2: # imgabs0. The electrolyte is used in the battery, so that the normal-temperature cycle, high-temperature cycle, high-temperature storage and low-temperature discharge performance of the battery can be improved.

The invention relates to the technical field of lithium ion batteries, in particular to an ultralow-temperature electrolyte and a lithium ion battery comprising the same, the electrolyte comprises a lithium salt, an organic solvent and an additive, and the organic solvent comprises cyclic carbonate and carboxylic ester; the lithium salt comprises lithium hexafluorophosphate and sulfonyl imide salt of at least one selected from lithium bis (fluorosulfonyl) imide or lithium bis (trifluoromethane) sulfonyl imide. The lithium ion battery comprises a positive pole piece, a negative pole piece, electrolyte and a diaphragm, the negative pole piece comprises a negative pole material layer containing a negative pole active material, and the negative pole active material comprises a silicon-based material and a carbon material; the lithium ion battery satisfies the following conditions: 0.2 < = (0.01 * E + D) / (S + 10 * L) < = 3.5, 500 < = E < = 1200, 2 < = D < = 50, 15 < = S < = 35, 0.1 < = L < = 0.5; in order to meet the requirement of high gram volume in a low-temperature environment, the negative pole piece with high gram volume and low resistivity is adopted, and the composition of the solvent and the lithium salt is regulated and controlled, so that the electrolyte still has relatively high ionic conductivity and low viscosity characteristics in the low-temperature environment, and the low-temperature charge-discharge performance of the lithium ion battery is further effectively improved.

The invention discloses an unsaturated carboxylic ester compound-containing lithium ion battery electrolyte, which comprises a main lithium salt, a non-aqueous solvent and an additive, and the additive at least comprises an unsaturated carboxylic ester compound as a first additive, a cyclic sulfate compound as a second additive and a lithium salt additive as a third additive, the specific structure is shown in the specification. When the first additive, the second additive and the third additive are added into the electrolyte to be applied to the lithium ion secondary battery, the second additive is added to facilitate the inhibition of the consumption of the first additive in the formation stage, and the second additive and the first additive cooperate to improve the high-temperature storage performance, the high-temperature cycle performance and the normal-temperature cycle performance of the battery; by adding the third additive, the internal resistance of the battery can be further reduced, and the low-temperature discharge performance is improved, so that the high-temperature and low-temperature performance of the battery can be considered.

The present invention discloses a safety coating and its application, an electrode sheet and a lithium-ion battery, and relates to the technical field of secondary battery materials. By limiting the particle size of inorganic fillers in the safety coating, the grading of large and small particles is achieved, which can make the safety coating have a denser structure, thereby reducing the probability of contact between the positive and negative electrodes, thereby improving the safety performance of the battery core. At the same time, the amount of binder in the safety coating is optimized to promote the absorption of electrolyte by the safety coating, which can improve the rate performance, low-temperature discharge performance and cycle performance of the battery core. Finally, the present invention can improve the rate performance, low-temperature discharge performance and cycle performance of the battery core while improving the safety performance of the battery core by limiting the particle size of inorganic fillers and selecting binders.

The present application provides a secondary battery and a device containing the secondary battery, wherein the secondary battery comprises a negative electrode plate, a negative electrode current collector and a negative electrode film disposed on at least one surface of the negative electrode current collector and comprising a negative electrode active material; an electrolyte, comprising an electrolyte salt, an organic solvent and an additive; the negative electrode active material comprises a silicon-based material; the additive comprises an additive A and an additive B; the additive A is selected from one or more of the compounds shown in Formula 1; the additive B is selected from one or more of the compounds described in Formula 2; the melting point of the additive B is less than or equal to 5°C. The secondary battery of the present application and the device containing the secondary battery can simultaneously take into account good high-temperature cycle performance, high-temperature storage performance and low-temperature discharge performance. #imgabs0#NC——R2——CNFormula 2.

The invention relates to a modified graphite negative electrode material and a preparation method thereof, a negative electrode and a lithium ion battery. The modified graphite negative electrode material comprises graphite particles and an SEI precursor layer which is uniformly coated on the surface of each graphite particle and is constructed by lithium salt, wherein the lithium salt is of a crystalline state structure, and the thickness of the SEI precursor layer is 1-500 nm; during the first charging and discharging process of the battery, the lithium salt of the SEI precursor layer is subjected to electrochemical reaction prior to electrolyte, and an inorganic phase SEI with LiF and / or Li3PO4 as a main component is formed on the surface of graphite particles in situ. The negative electrode material disclosed by the invention realizes active formation and uniform distribution of SEI, even in a thick electrode, a continuous SEI layer can be formed on the surface of a deep graphite particle in the first charge-discharge and cycle process of a battery, the first-cycle coulombic efficiency is remarkably improved, the cycle life is remarkably prolonged, and the low-temperature and rate performance is improved; in addition, the electrolyte can more easily infiltrate the electrode, so that Li < + > is more smoothly transmitted in the thick electrode, and the electrochemical performance of the electrode is improved.

This invention discloses a lithium-ion battery negative electrode slurry and its preparation method. The dry matter of the slurry is composed of the following components by mass percentage: 0.5%–2% conductive agent, 1.7%–2.2% binder, 0.5%–2% thickener, with the balance being negative electrode active material. The conductive agent is conductive carbon black, the thickener is sodium carboxymethyl cellulose, and the binder is a mixture of polyacrylic acid binder and styrene-butadiene rubber binder. The lithium-ion battery negative electrode slurry provided by this invention employs a polyacrylic acid and styrene-butadiene rubber composite binder system, which leverages the high bonding strength and low impedance advantages of PAA while imparting good flexibility to the electrode sheet through SBR, significantly reducing the brittleness and material shedding risk of the electrode sheet. Simultaneously, the slurry does not exhibit a blue discoloration phenomenon, demonstrates excellent stability, and the coated negative electrode sheet has high peel strength and low electrode resistance, effectively suppressing electrode sheet expansion and roller sticking problems, thereby improving the rate performance, low-temperature discharge performance, and cycle life of the lithium-ion battery.

This invention relates to the field of battery technology, specifically to a lithium-ion secondary battery. The lithium-ion secondary battery includes an electrode assembly, which includes a positive electrode sheet. The positive electrode sheet includes a positive current collector, a positive active layer, a protective layer, and a surface coating layer. The positive active layer is located on at least one side surface of the positive current collector, the protective layer is located between the positive current collector and the positive active layer, and the surface coating layer is located on the outer surface of the positive active layer away from the positive current collector. The thickness of the surface coating layer containing a solid electrolyte is 'a', where 'a' is 0.5 μm to 5 μm; the thickness of the protective layer is 'b', where 'b' is 0.2 μm to 5 μm; 0.1 ≤ a / b ≤ 10. The negative electrode sheet includes a negative current collector and a negative active layer comprising silicon-carbon material. One side outer surface of the positive electrode sheet has several protrusions. The lithium-ion secondary battery of this invention combines high energy density, low-temperature discharge performance, and needle penetration safety performance.

The present application provides an electrochemical device and an electronic device containing the same, wherein the electrochemical device comprises a positive electrode, a negative electrode, a separator and an electrolyte, wherein the electrolyte comprises an additive; the electrochemical device has a liquid retention coefficient of ag / Ah, satisfying 0.5≤a≤3.5; based on the total mass of the electrolyte, the mass percentage of the additive is b%, satisfying 0.005≤b≤3; wherein the additive comprises at least one of lithium bis(oxalatoborate), ethylene carbonate, methylene disulfonate, triallyl phosphate, trifluoromethylethylene carbonate or propenyl-1,3-sultone. The electrochemical device of the present application can effectively improve the low-temperature discharge performance and safety performance of the electrochemical device by adopting an appropriate electrolyte retention amount and adding an appropriate amount of the above-mentioned additives to the electrolyte. The electronic device containing the electrochemical device also has good low-temperature discharge performance and safety performance.

The invention provides a secondary battery and electric equipment. The secondary battery comprises a positive pole piece and an electrolyte, the positive pole piece comprises a positive current collector and a positive active material layer arranged on at least one surface of the positive current collector, the positive active material layer comprises a positive active material, the positive active material comprises lithium iron phosphate, and the lithium iron phosphate comprises secondary particles formed by gathering primary particles. The average particle size of the primary particles is D nm, the specific surface area of the lithium iron phosphate is BET m < 2 > / g, and D / BET is greater than or equal to 2 and less than or equal to 30; the electrolyte comprises an additive and an organic solvent, the additive comprises lithium fluorosulfonate, the mass percentage of the lithium fluorosulfonate in the electrolyte is a%, 0.05 < = a < = 0.5, the organic solvent comprises ethyl propionate, and the mass percentage of the ethyl propionate in the organic solvent is greater than or equal to 30%. The low-temperature discharge performance, the high-temperature storage performance and the high-temperature cycle performance of the secondary battery are improved by matching the proper positive electrode active material and the electrolyte.

The invention relates to a high-nickel ternary positive electrode material, a preparation method of the high-nickel ternary positive electrode material, a positive plate and a battery. The high-nickel ternary positive electrode material comprises secondary particles formed by aggregating primary particles, the high-nickel ternary positive electrode material satisfies the following conditions: in the primary particles of the secondary particles, the ratio A [101] / A [104] of the total surface area A [101] of the [101] crystal face to the total surface area A [104] of the [104] crystal face satisfies 0.05 < = A [101] / A [104] < = 0.3; the concentration of the cobalt element in the secondary particle is in gradient distribution which is sequentially decreased from the surface to the center, and the cobalt element concentration C [surface] in the surface area of the secondary particle and the cobalt element concentration C [core] in the core area of the secondary particle meet the condition that (C [surface]-C [core]) / C [core] is larger than or equal to 0.05 and smaller than or equal to 0.2. According to the scheme provided by the invention, the low-temperature discharge capacity, the high-temperature storage stability and the long cycle life of the ternary material can be synergistically improved.

The application discloses an electrolyte, a positive electrode, a lithium ion battery and a vehicle. The electrolyte comprises a lithium salt, an organic solvent and an additive, and the additive comprises a first additive, the first additive is a dicyano cyclic ether compound, and a structural formula of the dicyano cyclic ether compound is as follows: wherein n, x, y and z are each independent positive integers, and 1<=n<=3, 0<=x<=5, 0<=y<=5 and 0<=z<=5; R1 is selected from one of a hydrogen atom, a halogen atom, a C1-C5 alkyl group, a C2-C5 unsaturated alkyl group, a C6-C 10 aryl group or a C7-C 10 alkylaryl group; and the hydrogen atom in the C1-C5 alkyl group, the C2-C5 unsaturated alkyl group, the C6-C 10 aryl group or the C7-C 10 alkylaryl group can be partially or totally substituted by a substituent. The electrolyte disclosed by the application has a small impedance growth at low temperature, is beneficial to improve the low-temperature discharge performance of the lithium ion battery, can preferentially form a stable interface protection film on the surface of the positive electrode, and improves the battery capacity, cycle life and the like of the battery at high voltage.

This invention belongs to the field of secondary batteries, and provides a novel structural additive, a preparation method, a non-aqueous electrolyte containing the novel structural additive, and a secondary battery. The novel structural additive is a complex of an inner salt compound containing a hydrocarbon sulfonate anion and a quaternary ammonium cation with difluorophosphate, having the structure shown in Formula I: where R1 is a hydrocarbon-like group with 1-6 carbon atoms; R2 is a chain-like or cyclic quaternary ammonium cation; R3 and R4 are independently selected from one of , , , , or ; R5, R6, and R7 are independently selected from hydrocarbon groups or hydrocarbon oxygen groups; R8, R9, and R... 10 The elements are independently selected from hydroxyl groups; n=1~6, m=1~6, p=1~6, and n, m, and p are independent of each other; M is a metallic element selected from Li or Na. A non-aqueous electrolyte and a secondary battery containing this novel structural additive are provided, which can improve the battery's low-temperature discharge performance and high-temperature storage performance, and extend cycle life.

The application provides a battery and a power utilization device, a positive electrode sheet comprises a positive electrode active material, the positive electrode active material is doped and / or coated with a lanthanum element; a separator surface is coated with a ceramic coating; an electrolyte comprises a first solvent, a second solvent, a first additive and a second additive; the first solvent comprises a cyclic carbonate compound, the second solvent comprises a chain fluorosulfonamide compound, the first additive comprises mannitol carbonic acid sulfate, and the second additive comprises succinonitrile; by doping / coating the positive electrode active material with the lanthanum element, the application can effectively inhibit the release of lattice oxygen under high voltage or high temperature, and reduce the exothermic reaction activity at the thermal runaway starting temperature; the first additive and the second additive in the electrolyte form a dense, high-thermal-stability CEI film and SEI film on the positive and negative electrode surfaces respectively; the separator ceramic coating provides a physical barrier, improves the thermal shrinkage temperature of the separator, and prevents internal short circuit.

The invention relates to the technical field of batteries, in particular to a composite diaphragm, a preparation method thereof and a battery. The composite diaphragm comprises a base material and a functional coating arranged on at least one surface of the base material, the functional coating comprises porous ceramic particles, water-based polyamide and an auxiliary agent; and the particle size D50 of the porous ceramic particles is 0.4-0.6 mu m. The diaphragm provided by the invention has high heat resistance, effectively enhances the wettability of an electrolyte, improves the lithium ion transmission efficiency, effectively inhibits the increase of the air permeability value of the diaphragm, and improves the low-temperature discharge performance of the battery. Moreover, a water-based coating process can be adopted, so that the risk that an oil coating process is high in difficulty and high in environmental pollution is avoided.

The invention discloses a non-aqueous electrolyte and a lithium ion battery, the non-aqueous electrolyte comprises a lithium salt, a non-aqueous organic solvent and an additive, the additive comprises a compound A shown in a formula 1, # imgabs0 #, M is selected from O = S = O or C = O, and R is selected from CH2, CHF or CF2. The molecular radius of the compound A is large, the dissociation degree of lithium ions in the electrolyte can be improved, so that the conductivity of the electrolyte is improved, ohmic resistance in the battery is reduced due to improvement of the conductivity, heat generated in the charging and discharging process is reduced due to low ohmic resistance, and the service life of the battery is prolonged. Meanwhile, the high-conductivity electrolyte is also beneficial to improving the migration speed of lithium ions at a low temperature; importantly, the compound A can also participate in formation of a thinner, uniform and compact SEI film on the surface of the electrode, so that side reaction of electrolyte is inhibited, interfacial film impedance and potential difference polarization in the charge-discharge process are reduced, the transmission rate of lithium ions is improved, and the discharge performance of the battery under the low-temperature condition can be remarkably improved.

The application provides a lithium iron phosphate positive electrode active material, a preparation method of the lithium iron phosphate positive electrode active material, a positive electrode sheet, a battery, a battery pack and an electric device. 16 spins / g~2.0000×10 16 spins / g. The lithium iron phosphate positive electrode active material provided by the application has a high compaction density and has normal temperature rate discharge and low temperature discharge performance.

The invention provides an electrolyte and a secondary battery. The electrolyte comprises a solvent, an electrolyte and an additive, wherein the additive comprises a first component and a second component; the first component is selected from fluoroethylene carbonate, the second component is selected from a compound shown as a formula I, based on the mass of the electrolyte, the mass percentage content of the first component is a, a is more than or equal to 5% and less than or equal to 20%, the mass percentage content of the second component is b, and b is more than or equal to 0.1% and less than or equal to 2%. The synergistic effect of the first component and the second component can improve the high-temperature cycle performance, the high-temperature storage performance and the low-temperature discharge performance of the secondary battery and reduce the impedance.

This invention discloses a negative electrode sheet and a lithium-ion battery. The negative electrode sheet includes at least two sets of active units coated sequentially from one side of a negative electrode current collector. Each set of active units includes a graphite negative electrode layer and a hard carbon negative electrode layer coated sequentially from the inside out. The graphite negative electrode layer has multiple pores spaced apart on the side adjacent to the hard carbon negative electrode layer, and hard carbon negative electrode material for forming the hard carbon negative electrode layer is embedded within these pores. The pore capacity between each set of active units increases sequentially from the inside out. This invention, by optimizing the negative electrode sheet structure, can significantly improve the low-temperature charge-discharge cycle performance of the battery. This multi-layer negative electrode sheet has the advantages of high charging efficiency and strong low-temperature charge-discharge capability, which can significantly improve the high-rate charge-discharge performance of lithium-ion batteries and extend the electrode life under high-rate charge-discharge conditions.

The utility model discloses a wear-resistant storage battery PE partition plate, which relates to the technical field of storage battery PE partition plates and comprises a PE partition plate main body, ribs are uniformly distributed on the periphery of the outer surface of the PE partition plate main body, and discontinuous ribs are arranged on the periphery of the outer surface of the PE partition plate main body and positioned among the ribs. An insulating film is fixedly arranged on the inner surface of the PE partition plate main body, the inner surface of the PE partition plate main body is divided into an upper layer, a middle layer and a lower layer and is fixedly provided with a rubber ring, the insulating film is a PI film, the inner side end of the rubber ring penetrates out of the insulating film by 2mm-4mm, the inner side end of the rubber ring is arranged in a downward inclined mode, the downward inclined angle of the rubber ring is alpha, and alpha is larger than 30 degrees and smaller than or equal to 45 degrees. Compared with an existing common storage battery PE partition plate, the wear-resistant storage battery PE partition plate has the advantages that the negative plate is fully prevented from shaking and continuously rubbing with the PE partition plate main body, friction is reduced, wear resistance is improved, the influence of vibration on the negative plate can be reduced, and the negative plate is more stable.

The invention provides a positive electrode material composition, a positive plate, a preparation method of the positive plate and a lithium ion battery. The positive electrode material composition comprises the following components in parts by weight: 80 to 99 parts of a positive electrode active material, 0.1 to 20 parts of a conductive agent, 0.2 to 20 parts of a binder, 0.1 to 5 parts of a fast ion conductor and 0.1 to 5 parts of a lubrication aid, wherein the lubrication aid is metal ion modified nano cellulose. The fast ion conductor can still keep high ionic conductivity at low temperature, and the addition of the fast ion conductor is beneficial to improving the migration efficiency of lithium ions among electrode materials, reducing the impedance in the battery and enabling the lithium ion battery to provide more stable and higher-capacity discharge in a low-temperature environment. The metal ion modified nano cellulose is used as the wetting aid, so that the wettability of the positive plate is improved, the liquid retention of the positive plate is improved, and the low-temperature performance of the lithium ion battery is improved.

The invention belongs to the field of lithium ion battery positive electrode materials, and particularly relates to a treatment method of lithium iron phosphate and application of the lithium iron phosphate in a low-temperature lithium ion battery. The treatment method comprises the following steps: mixing lithium iron phosphate with water, stirring and leaching for more than 0.5 h, and then carrying out solid-liquid separation to obtain the lithium iron phosphate material. According to the method, residual lithium near the surface of the lithium iron phosphate particles and internal lattice lithium are removed from the positive electrode material in an agitation leaching manner, lithium vacancies are constructed in the material, and the diffusion coefficient of lithium ions is increased, so that the low-temperature dynamic performance of the lithium iron phosphate positive electrode material is improved.

The application discloses an electrolyte, a secondary battery and a power utilization device, and belongs to the battery field. The electrolyte comprises a first additive, and a chemical structural formula of the first additive comprises a heterocyclic ring and a thiourea group. The electrolyte disclosed by the application can improve the high-temperature storage performance, low-temperature discharge performance and cycle performance of the battery.

The present invention discloses a method for preparing an efficient lithium-ion battery electrolyte based on a novel polymer, and relates to the technical field of battery electrolytes. The polymer electrolyte of the present application can achieve high ion conductivity through reasonable molecular design and polymerization reaction, ensure rapid transmission of lithium ions in the battery, reduce the migration resistance of ions during transmission, effectively improve the ionic conductivity of the electrolyte, and ensure that lithium ions can still migrate quickly and smoothly between positive and negative electrodes in a low-temperature environment, thereby avoiding the problem of discharge capacity attenuation caused by decreased conductivity, so that the battery can still maintain a high working efficiency under extremely cold conditions, and by adding a variety of different functional additives, reduce the diffusion resistance of lithium ions in the electrolyte, reduce its non-selective reaction on the electrode surface, thereby improving the cycle efficiency and overall performance of the battery.

The application provides a lithium ion battery and application thereof. The lithium ion battery comprises a negative electrode sheet and an electrolyte. The negative electrode sheet comprises a negative electrode current collector and a negative electrode active layer arranged on at least one functional surface of the negative electrode current collector. The electrolyte comprises propylene carbonate and a first additive. The specific surface area A of graphite particles in the negative electrode active layer, the mass percentage B of the propylene carbonate in the electrolyte and the mass percentage C of the first additive in the electrolyte satisfy 5 < B / A < 20 and 0.01 < C / B < 0.2. The lithium ion battery has high cycle performance and low-temperature discharge performance.