POROUS POLYMER FILM-SEPARATOR TO ENSURE SAFETY OF METAL-ION ACCUMULATOR Russian patent published in 2024 - IPC H01M50/409 B01D71/26 

FIELD: electrical engineering.

SUBSTANCE: invention can be used in the manufacture of metal-ion accumulators, as well as storage batteries based on them, for protection against short circuit effects. Disclosed is a porous separator film made of one or more connected layers made from chemically resistant materials: polyethylene, polypropylene, polyvinylidene difluoride, polyethylene terephthalate. Set of parameters determining the configuration of the film is within the following ranges: separator thickness—from 5 to 50 mcm, separator porosity—from 10 to 45%, permeability for liquid electrolyte—from 0.5 to 500 l/(m²·h·atm), number of pores per unit surface area of the separator—from 0.3·10⁷ to 3·10⁸ 1/cm², average pore size from 25 to 400 nm, maximum pore size from 60 to 2,000 nm, tortuosity of pores from 1 to 3. Said characteristics provide non-linear change in electrolyte permeability in the range of current density values from 0.1 to 50 mA/cm², dividing the range of permeability values into two areas: with low resistance to electrolyte flow and with high resistance to electrolyte flow. Film-separator described in the invention has a nonlinear nature of change in permeability for electrolytic transfer of metal ions depending on the value of current density. Besides, it is possible to influence the character of nonlinearity of permeability by means of selection of parameters of configuration of porous film.

EFFECT: disclosed is a porous polymer film-separator to ensure the safety of a metal-ion accumulator.

3 cl, 4 dwg, 3 tbl, 6 ex