METHOD OF PRODUCING CARBON NONWOVEN MATERIAL Russian patent published in 2016 - IPC D04H1/00 

FIELD: electrochemistry.

SUBSTANCE: invention relates to production of carbon nonwoven materials, including for use as material for making gas diffusion electrodes of electrochemical current sources. Method of producing carbon non-woven material, involving formation of three-layer non-woven material from viscose material consisting of two needle-felt outer layers and inner carcass layer, followed by needling, then carbonisation of non-woven material in nitrogen medium with gradual temperature raise to 600-700 °C and further graphitation at temperature of 1,500-2,500 °C, wherein formation of three-layer non-woven material is performed by displacement relative to each other by 1.5-2 mm of two needle-felt external layers with different number of punctures in ratio 1:2 with surface density of one layer of 72-150 g/m² and number of punctures 6-18 per 1 cm² and surface density of 45-120 g/m² and number of punctures 12-36 per 1 cm² for another layer made from viscose stapled fibres with length of not less than 51 mm, and carcass layer with surface density of 50-120 g/m², consisting of a thin fabric formed by linen weave of viscose threads at an angle of 90 degrees with linear density of 13-52 Tex with mesh size from 1×1 to 4×4 mm, needling to produce a non-woven viscose material with bulk density of 71-112 kg/m³.

EFFECT: technical result is improvement of manufacturability of process by avoiding stage of additional orientation of carcass layer due to reinforcement of outer layers of nonwoven materials from stapled fibres of sparse fabric formed by linen weave of viscose fibres, with simultaneous increase in strength throughout volume of produced graphite nonwoven materials due to introduction of a thin fabric, reduction of electric resistance and maintaining air permeability by forming channels with complex curved shape, which together with through channels form porous structure with possibility to adjust air permeability and more stable supply of gases into reaction zone during operation of gas diffusion electrodes of electrochemical current sources.

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