Conductive catalytic composite material interlayer for battery as well as preparation method and application of conductive catalytic composite material interlayer

Abstract

The invention belongs to the technical field of composite materials, and particularly relates to a conductive catalytic composite material interlayer for a battery as well as a preparation method and application of the conductive catalytic composite material interlayer. The conductive catalytic composite material interlayer for the battery, provided by the invention, is a Co9S8@carbon nanofiber membrane interlayer with a conductive catalytic function, which is obtained by uniformly coating Co9S8 on the surface of carbon nanofiber in an in-situ growth manner. The cluster structure of Co9S8 not only can effectively reduce the pore size of the carbon nanofiber, but also is favorable for forming physical barrier on polysulfide; the specific surface area of the fiber can be increased, and sufficient contact between the interlayer material and electrolyte is facilitated; the synergistic effect of the conductive function of the carbon nanofiber and the catalytic function of Co9S8 can effectively promote the conversion of polysulfide. When the conductive catalytic composite material interlayer for the battery is applied to the lithium-sulfur battery, the purpose of improving the performance of the battery can be achieved.

Description

technical field [0001] The invention belongs to the technical field of composite materials, and more specifically relates to a conductive catalytic composite material interlayer for batteries, a preparation method and application thereof. Background technique [0002] As we all know, lithium-ion batteries are now widely used in various electronic products such as mobile phones and notebook computers. With the continuous development of electric vehicles and green energy, the demand for high energy density rechargeable batteries is also increasing. Lithium-sulfur batteries have a high theoretical specific capacity (1675mAh g -1 ) and energy density (about 2600Wh g -1 ) (Chemical Engineering Journal, 2019, 355:390-398) and become one of the very attractive candidates. [0003] During the cycle of lithium-sulfur batteries, the discharge curve usually has two voltage plateaus, and the charge curve has a voltage plateau. The ideal discharge process is ring-s 8 is reduced and ...

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Problems solved by technology

Molybdenum disulfide (MoS 2 ) loaded on the commercial polypropylene battery separator (PP) (Advanced Materials, 2017, 29(21): 1606817), although it can effectively inhibit the polysulfide shuttle effect, the suction filtration usually leads to a very dense material structure, which is not conducive to lithium conduction of ions

Jingbo Yang et al. flower-like titanium dioxide (titanium-deficient anatase TiO 2 , TDAT) mixed with conductive carbon black (Super P) and then scraped onto commercial polyethylene battery separator (PE) (Nanoscale, 2020, 12(7): 4645-4654) to obtain a conductive catalytic interlayer. The flower-like structure of TDAT can Increase the contact area between the interlayer and the electrolyte, the electrical conductivity of Super P and the catalytic effect of TDAT can jointly promote the conversion of polysulfides, but the scrape-coated materials are usually thicker and loose in structure, and some polysulfides may not be available in time Trapped and transformed through the mezzanine

Patent CN110707383B obtains polymer fiber film by electrospinning after blending vanadium-containing compound and polymer, and then obtains amorphous vanadium oxide / carbon nanofiber film interlayer by high-temperature carbonization; patent CN109768284A uses magnetron sputtering technology on polymer Polar alumina particles are sputtered on the surface of the acrylonitrile fiber membrane, and then the alumina / carbon nanofiber membrane interlayer is obtained by high-temperature carbonization. These interlayer materials can capture polysulfides through physical barrier or chemical adsorption, and then utilize the carbon nanofiber membrane. The conductivity and catalytic properties of inorganic particles convert polysulfides, but the large pores between the fiber membranes cause some polysulfides to pass directly through the fiber membrane interlayer

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