33results about How to "Solve capacity fading" patented technology

The invention relates to the technical field of lithium ion batteries, in particular to a gel polymer energy storage lithium ion battery and a preparation method thereof. The gel polymer energy storage lithium ion battery comprises a positive plate, a negative plate, a separation film, a bath solution and an aluminum plastic film housing, wherein the positive plate and the negative plate are wound by the separation film, and are placed in the bath solution; the aluminum plastic film housing is used for accommodating the positive plate, the negative plate, the separation film and the bath solution; in addition, (1) the cathode material of the positive plate is formed by a positive active material, an anode conductive agent and an anode binder; (2) the anode material of the negative plate is formed by a negative active material, a cathode conductive agent and a cathode binder; (3) the separation film is a gel polymer coating separation film. The lithium ion battery provided by the invention is long in cycle life, high in safety performance, high in specific energy and low in fabricating cost, and can be used for various energy storage devices.

The invention relates to the technical field of preparation of a nanometer material, in particular to a preparation method for a hollow micro-structure Co3S4@C@MoS2 of a lithium ion battery negative electrode by an MOF template. The method comprises the following steps of (1) preparing a ZIF-67 precursor template by a solution method; (2) coating the prepared ZIF-67 template with organic carbon ina solution; (3) performing high-temperature sintering on a product in an atmosphere furnace; (4) dispersing the sintered product in a salt solution; (5) performing hydrothermal reaction on a mixed solution, and collecting the product; (6) annealing the product to prepare a hollow Co3S4@C@MoS2-heterojunction structure. The method is simple, is convenient to operate, and is good in repeatability and high in product purity; and the prepared hollow Co3S4@C@MoS2-heterojunction structure has favorable performance when used as a lithium ion battery.

The invention discloses a negative electrode material and a negative electrode sheet of a lithium ion secondary battery, and the lithium ion secondary battery. According to the preparation method, a silicon-based negative electrode active material and a graphite negative electrode active material are compounded to serve as a negative electrode active material, the silicon-based negative electrodeactive material takes a high-capacity silica material SiOx as a core, and the surface of the silicon-based negative electrode active material is coated with a carbon active substance; and meanwhile, conductive agents such as single-walled carbon nanotubes are added into the negative electrode material. Through the arrangement, the energy density of the lithium ion secondary battery can be improved, the electronic conductivity of the silicon-oxygen material is improved, the volume change of the silicon-oxygen material in battery circulation is favorably buffered, meanwhile, the first coulombicefficiency of the silicon-oxygen material is improved, and the problems of low first coulombic efficiency and poor rate capability of the silicon-oxygen material can be effectively solved.

The invention discloses a composite porous membrane liquid flow battery and its application in preparation of liquid flow in a battery, by one or more than two kinds of as prepared porous membrane organic polymer resin or sulfonated polymer resin as matrix, respectively on two sides of the matrix composite Yang, anionic organic resin to form a composite porous membrane.

The invention discloses a nanometer zinc oxide/porous carbon in-situ composite high-capacity lithium ion battery material and a preparation method thereof, and belongs to the technical field of production of an electrode material. The preparation method comprises the steps of preparing a zinc citrate precursor by taking zinc chloride and sodium citrate as raw materials and by employing a deposition method, and obtaining the nanometer zinc oxide/porous carbon in-situ composite material by a direct carbonization method. In the nanometer zinc oxide/porous carbon in-situ composite prepared according to the method, the zinc citrate is formed from citrate radicals and zinc ions in a complexing mode, the zinc ions are controlled on an in-situ site to generate zinc oxide, the citrate radicals are decomposed to generate a porous carbon material, and finally, the nanometer zinc oxide/porous carbon in-situ composite material of which the nanometer zinc oxide is uniformly dispersed in porous carbon and which is provided with an in-situ composite structure is formed. By the nanometer zinc oxide/porous carbon in-situ composite material, the problem of capacity attenuation caused by volume effect of the zinc oxide and low conductivity can be effectively solved, so that high specific capacity, favorable circulation and rate performance can be achieved.

The invention discloses a nitrogen and sulfur co-doped three-dimensional graphene and transition metal sulfide composite material, as well as a universal preparation method and application thereof. According to the invention, the thiocyanuric acid is adopted as a nitrogen and sulfur doping agent, a three-dimensional graphene soft mold agent and a transition metal vulcanizing agent. The hydrothermal-heat treatment method is adopted to realize the simultaneous and in-situ construction of a composite structure of a transition metal sulfide completely coated with doped graphene. The metal sulfideis completely coated with nitrogen and sulfur co-doped graphene. According to the structural design, the problem of capacity attenuation caused by volume expansion of transition metal sulfide in the lithium storage or sodium storage process can be obviously solved. The preparation method is safe in process and easy to operate, wherein the mass production can be achieved. The prepared composite material can be used as a lithium ion battery and sodium ion battery negative electrode active material.

The invention provides a method for prolonging cycle life of a lithium ion battery by piezoelectric ceramic. A small quantity of piezoelectric ceramic crystals are adopted in preparation of a precursor of a positive electrode material of a lithium battery; and when lithium ions are in mobility, the piezoelectric ceramic crystals, which suffer from an external electric field effect, generate mechanical deformation so as to suppress structural changes of lithium cobalt oxides, lithium manganate, lithium iron phosphate, lithium nickel cobalt phosphate and other lithium ion positive electrode materials in a cyclic charging-discharging process. Therefore, the problem of capacity fading of the electrode material in a cyclic process is solved fundamentally, the reversibility of the cyclic charging-discharging process is improved, and the cycle life is greatly prolonged; and in addition, lithium ions can pass freely and high electric conductivity is achieved, so that the initial efficiency and the rate capability of the lithium battery are improved.

The invention discloses a high-capacity TiO2-VO2-doped hollow carbon nanofiber lithium battery negative electrode material and a preparation method thereof. The high-capacity TiO2-VO2-doped hollow carbon nanofiber lithium battery negative electrode material comprises 10-80.0 wt% of TiO2 nanoparticles and 0.1-20.0 wt% of VO2 nanoparticles coating the outer surface of the hollow carbon nanofiber andbalance of hollow carbon nanofiber; and the high-capacity TiO2-VO2-doped hollow carbon nanofiber lithium battery negative electrode material has multi-stage pore structure and high load, is beneficial to electrolyte in-penetration, and is conducive to lithium ion embedding and electron transport. The conductivity, specific capacity and stability of the negative electrode material are improved, and the negative electrode material has excellent rate performance and cycle performance.

The invention discloses an electrolyte storage tank, a redox flow battery, a box-type redox flow battery system and a charge-discharge control method of redox flow battery. A ring tube I and a ring tube II are arranged in the electrolyte storage tank, wherein the ring tube II communicates with an electrolyte return hole, the ring tube I communicates with an electrolyte output, the annular perimeter of the ring tube I is not equal to the annular perimeter of the ring tube II, and a plurality of liquid holes are formed in tube walls of both of the annular tube I and the annular tube II. By a multi-layer ring tube structure in the storage tank, an electrolyte flowing dead zone of an electrolyte in the storage tank is greatly reduced, the flowing of the electrolyte is more uniform, and the utilization of the electrolyte is effectively improved; and moreover, since the longitudinal distance between the electrolyte output and the electrolyte return hole is reduced, the problem of SOC lag is effectively solved, and the SOC monitoring accuracy of the redox flow battery is improved.

The invention relates to an all-vanadium redox flow battery capacity recovery method and particularly aims at solving the problem that battery capacity is faded due to accumulation of positive pentavalent vanadium when an all-vanadium redox flow battery operates for a long time. According to the method, appropriate amount of ammonium ferrous sulfate can be added to a positive electrolyte in a battery charge and discharge random process, so the ammonium ferrous sulfate reacts with pentavalent vanadium ions in the positive electrolyte, the pentavalent vanadium ions are restored into tetravalent vanadium ions and a battery capacity is recovered. According to the method, the appropriate amount of ammonium ferrous sulfate is added to the positive electrolyte as reductant, the pentavalent vanadium accumulation problem when the battery operates for a long time, the capacity fading problem is finally solved, so the battery can operates stably for a long time and the electrolyte is efficiently utilized. The method is simple in technology, simple and convenient in operation, low in cost and remarkable in effect; and raw materials are simple and easy to get.

The invention belongs to the technical field of inorganic material preparation and battery materials, and relates to a carbon-oxygen double-doped porous hollow bowl-shaped carbon material and a preparation method thereof. The material is carbon bowl-shaped structure particles, which are high in dispersity, narrow in particle size distribution and controllable in particle size; a hollow structure exists in the particles, the appearance is in a concave bowl shape, and the wall thickness is controllable; a plurality of holes are formed in the bowl wall and comprise micropores and mesopores, so that the specific surface area is high. The material has the characteristic of double doping of nitrogen and oxygen elements, and can be used for a potassium ion battery negative electrode with high volume specific capacity and cycling stability. Due to the characteristics of rich potassium global reserve and low oxidation-reduction voltage value, the potassium ion battery is considered to be one of traditional high-price lithium ion battery candidates; however, the size of potassium ions is large, so that the potassium ion battery electrode material with high specific capacity and good cycling stability and rate capability is lacked in the prior art. The material is used for potassium ion battery electrodes, and the purposes of enhancing the stability of the potassium ion battery, improving the rate capability and improving the volume specific capacity of the battery are achieved.

The embodiment of the invention provides a positive electrode active material, which comprises a secondary particle formed by tightly stacking a plurality of primary particles, wherein closed pores are formed in the primary particles, the sizes of the closed pores are within the range of 1 to 300 nm, the primary particle comprises a compound LicNiaCobM1-a-bO2-dXd, M is selected from one or more ofMn, Al, Na, Mg, Ca, Zr, Sr, Ti, Cr, V, W, Si, Ga, Sn, lanthanide series elements and actinide series elements, X is selected from one or more of B, F, Cl and S, a is greater than or equal to 0 and less than or equal to 1, b is greater than or equal to 0 and less than or equal to 1, c is greater than or equal to 0.8 and less than or equal to 1.5, and d is greater than or equal to 0 and less than or equal to 0.5. According to the invention, the closed pores in the primary particles of the positive electrode active material can effectively release internal stress caused by volume change of the material in the lithium intercalation and deintercalation process, so that the cycling stability of the positive electrode active material is improved. The embodiment of the invention also provides a preparation method of the positive electrode active material, and a lithium secondary battery.

The invention discloses a zinc oxide microsphere, an electrode and a preparation method thereof, and the preparation method of the zinc oxide microsphere comprises the following steps: 1) preparing a mixed solution; 2) reacting the mixed solution to prepare zinc-based glycerate; and 3) calcining the zinc-based glycerate to prepare zinc oxide microspheres. The zinc oxide microspheres which are controllable in size, controllable in internal structure and uniform in size are prepared through a simple solvothermal method by utilizing the reaction of the zinc salt, the glycerol and the isopropanol which are low in price. When the zinc oxide microsphere is used as a lithium ion battery negative electrode material, an electrochemical test result shows that the zinc oxide microsphere has high specific discharge capacity and excellent cycle performance. According to the method, expansion and shrinkage of zinc oxide in the charging and discharging process are effectively relieved, the problem of capacity fading caused by the volume effect can be effectively solved, and good cycle performance is achieved.

A novel valve controlled sealing lead acid storage battery activated charge-discharge device comprises a first storage battery, a second storage battery, a third storage battery and a large battery. The first to third storage batteries are connected with the large battery separately via the conducting wires, a boost circuit and a buck circuit are arranged on the conducting wires and are connectedin parallel, and the first to third storage batteries are connected with the voltage detection modules, a microcontroller and a driving module orderly. The driving module is connected with the boost circuit and the buck circuit and is used to drive the boost circuit and the buck circuit, the large battery is connected with the second voltage detection modules, and the second voltage detection modules are connected with the microcontroller separately. By adding the boost and buck circuits during the charge and discharge process of the storage batteries to realize the repeated charge and discharge operations, the novel valve controlled sealing lead acid storage battery activated charge-discharge device and the novel valve controlled sealing lead acid storage battery activated charge-discharge method provided by the present invention enable the capacity of the batteries to be improved and the service lives to be prolonged.