6 results about "Volume expansion" patented technology

The present invention relates to a rechargeable battery that can use a negative electrode active material having a high volume expansion rate by receiving volume variation of an electrode assembly in a case. The rechargeable battery according to the present invention includes i) an electrode assembly including a positive electrode plate, a negative electrode plate, and a separator that are wound in a jelly roll shape to have a flat portion and curved portions disposed at both sides of the flat portion, ii) a case for receiving the electrode assembly, and iii) a cap assembly combined with the case to close and seal the case and that is electrically connected to the electrode assembly. When a direction that is perpendicular to a surface of the separator disposed in the flat portion is set to a first direction, the thickness of the flat portion measured along the first direction is smaller than the maximum thickness of the curved portion measured along the first direction.

The invention discloses a high-specific-energy flexible integrated electrode and a preparation method therefor. The electrode is prepared from the following components based on mass percentage: 20-80% of graphene, 0-10% of conductive carbon black, and 10-80% of sulfur-containing material, wherein the content of the conductive carbon black is not zero; the graphene and the conductive carbon black form a flexible graphene/conductive carbon black self-supporting thin film; and the sulfur-containing material is elementary sulfur or -S<m->-structured polysulfide, wherein m is greater than 2. By virtue of the high-specific-energy flexible integrated electrode prepared by the invention, the utilization rate of sulfur in the electrode is improved; in addition, the high-specific-energy flexible integrated electrode is high in conductivity and mechanical performance, capable of effectively relieving volume expansion of an active material in the charge-discharge process, and capable of improving the cycle performance and high specific energy characteristic of a battery.

The invention discloses a method for producing a ytterbium-doped lithium nickel cobalt manganese oxide material used for a lithium ion battery. The method comprises the following steps: a) weighing the raw materials according to stoichiometric ratio; b) adding absolute ethyl alcohol in the raw materials, performing ball milling and taking the materials out and drying the materials; c) adding acetate fibre, potassium chloride and sodium chloride in the raw materials obtained in the step 2) for mixing with molten salt and absolute ethyl alcohol, performing ball milling and drying the materials; and d) sintering the raw materials obtained in the step c), cooling the materials, washing the obtained powder, and drying to obtain the material. The ytterbium-doped lithium nickel cobalt manganese oxide material has higher discharge capacity and gram capacity; and has a hollow tube structure, through further processing, the tube wall is loosening so as to alleviate the volume expansion problem; inorganic filling material titanium dioxide in the acetate fibre is used, and is doped into crystal lattice of the ytterbium-doped lithium nickel cobalt manganese oxide material, so that stability of the ytterbium-doped lithium nickel cobalt manganese oxide material is improved, and the capacity attenuation problem of the lithium ion battery is improved.

The invention discloses a low-shrinkage dual-curing active monomer and a preparation method thereof. The monomer contains both double bonds and an oxetane structure, oxetane can participate in cationic curing, and the double bonds can participate in free radical curing, and the curing activity is relatively high; meanwhile, the oxetane structure has the volume expansion capability in a curing process, and for the monomer with the structure, a volume shrinkage effect achieved by polymerization of the double bonds of the monomer can be canceled by effectively utilizing an expansion effect achieved during ring opening of the oxetane, so that the volume of the whole monomer is prevented from being greatly shrunk after polymerization crosslinking, the coating stress is reduced, and the adhesive force is improved. The preparation method for the monomer comprises the following steps: reacting ethanol with (methyl) acryloyl chloride, performing washing with alkali liquor and a salt solution, and performing spin-drying to obtain a target product. The preparation method is simple and high in yield, and the reaction is stable and easy to control.

Provided are a negative electrode including a current collector, a first active material layer including first active material particles and disposed on the current collector, and a first pattern and a second pattern alternately disposed separately from each other on the first active material layer, wherein the first pattern includes first pattern active material particles, the second pattern includes second pattern active material particles, a thickness of the first pattern is greater than a thickness of the second pattern, and a volume expansion rate of the second pattern is greater than a volume expansion rate of the first pattern, and a secondary battery including the negative electrode.