Changzhou Zhongke Laifang Power Development Co., Ltd.

Chengdu Zhongke Laifang Power Science & Technology Co., Ltd.

Sichuan Indigo Technology Co., Ltd.

Hongchang Du

Zhonglai Pan

Lu Wang

Jiandong Gao

Rengui Li

Jiamin Deng

Jishuan Suo

Zhenghua Deng

Kai Wang

Zhenghua Den

Chuan Lyu

Xiaozheng Zhang

The invention relates to an acrylonitrile copolymer binder and application thereof in lithium ion battery, belonging to the field of lithium ion battery. The technical problem to be solved by the invention is to provide an acrylonitrile copolymer binder comprising the following structural units in percentage by weight: 78-95% of acrylonitrile unit, 1-10% of acrylic ester unit and 2-15% of acrylamide unit. For the binder of the invention, acrylonitrile monomer is taken as the main body, and acrylic ester monomer, acrylamide monomer or acrylate salt monomer with strong polarity is added to acrylonitrile for copolymerization to enable the flexibility of a polymer membrane, the affinity of an electrolyte and the proper swelling degree in the electrolyte while keeping strong adhesion or intermolecular force of acrylonitrile polymer molecules, so as to fit the periodic volume changes of electrode active materials along with lithium ion intercalation/deintercalation in charging and discharging processes, thereby improving the energy density and cycle performance of the lithium ion battery.

Acrylonitrile copolymer binder and application thereof in lithium ion batteries

The invention belongs to the technical field of the preparation of lithium ion batteries, and particularly relates to a water-based composition used for modifying diaphragm of lithium ion batteries and a polyolefin diaphragm for lithium ion batteries and lithium ion batteries. The invention aims to improve the strength of the battery cell, to reduce the expansion of thickness of battery cell at high temperature and to simplify the battery production process. The water-based composition for modifying the diaphragm for the lithium ion battery comprises a water-based adhesive for the lithium ion battery and organic nano-particle fillings dispersed in the water-based adhesive; the organic nano-particle fillings are nano-particles of the polymers 1 or nano-particles at least wrapped with the polymers 1 on the surfaces; and the particle sizes of the organic nano-particles are 50 to 2000 nm. The polymers 1 are selected from at least one of polymethyl methacrylate (PMMA), ethylene-vinyl acetate copolymer (EVA), ethylene-acrylate copolymer (EAA), ethylene-butyl acrylate copolymer (EBA), ethylene-methyl acrylate copolymer (EMA), ethylene-ethyl acrylate copolymer (EEA) or polyurethane (PTU) polymer.

Water-based composition used for modifying diaphragm for lithium batteries and modified diaphragm and batteries

Microporous polyolefin membrane modified by aqueous polymer of the invention is obtained by the following steps: copolymerizing 100 parts of a water-soluble polymer, 30-500 parts of a hydrophobic monomer, 0-200 parts of a hydrophilic monomer and 1-5 parts of an initiator into polymeric colloid emulsion; adding 0-100% of an inorganic filler and 20-100% of a plasticizer based on 100% solid content of the polymeric colloid emulsion to obtain slurry; and coating the slurry on one or two surfaces of the surface modified microporous polyolefin membrane and then drying. The microporous polyolefin membrane modified by aqueous polymer has thermal shutdown effect and little thermal shrinkage, and improves the main problem of shrinkage of the microporous polyolefin membrane at high temperature.

Microporous polymer membrane modified by aqueous polymer, manufacturing method and use thereof

Provided are separators used in power accumulators such as lithium ion secondary batteries and a preparation method thereof. The said separators are obtained through following steps: providing a polymer colloidal emulsion through a polymerization reaction of polyvinyl alcohol, hydrophobic monomer and hydrophilic monomer in water solution initiated by an initiator; coating a plastic substrate with the said polymer colloidal emulsion using tape-casting method; drying the plastic substrate coated with the polymer colloidal emulsion, and then obtaining the said separators by delaminating them from the substrate. The said separators have good liquid absorbability, high liquid absorption rate and retention, low resistivity, good mechanical strength and good thermal stability (little thermal shrinkage and little size distortion) as well as electrochemical stability. The prepared lithium ion batteries have good cycle stability and long service life.

Microporous polymer separators for lithium ion batteries and method for producing the same

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Sichuan, China

Hongchang Du