Fluoropolymer hybrid composite

A process for manufacturing a polymer electrolyte based on a fluoropolymer hybrid organic/inorganic composite, said process comprising the following steps:

• (i) providing a composition comprising a pre-gelled metal compound [compound (P-GM)] obtained by partially hydrolysing and/or polycondensing a metal compound [compound (M)] having formula:
• X4-mAYm
• wherein m is an integer from 1 to 4, A is a metal selected from the group consisting of Si, Ti and Zr, Y is a hydrolysable group selected from the group consisting of an alkoxy group, an acyloxy group and a hydroxyl group, X is a hydrocarbon group, optionally comprising one or more functional groups;
• in the presence of:
• an electrolyte solution [solution (ES)] comprising at least one metal salt [metal salt(S)] and a liquid medium [medium (L)];
• at least one acid catalyst;
• and
• optionally, an aqueous medium;
• said pre-gelled metal compound [compound (P-GM)] comprising one or more inorganic domains consisting of ≡A-O-A≡ bonds and one or more residual hydrolysable groups Y;
• and then
• (ii) reacting in the molten state at least a fraction of hydroxyl groups of a functional fluoropolymer comprising at least one hydroxyl group [polymer (F)] with at least a fraction of hydrolysable groups Y of said compound (P-GM), so as to obtain a polymer electrolyte comprising a fluoropolymer hybrid organic/inorganic composite incorporating the electrolyte solution (ES)
• wherein the polymer electrolyte has a uniform atomic element distribution having an incorporation of silicon of not more than 61% difference from the theoretical expected value, as measured by energy dispersive spectroscopy analysis by scanning electron microscopy according to
• SiO2[%]=[[SiO2]/([SiO2]+[F])]×100 (1)
• wherein [SiO2] and [F] from equation (1) are calculated using the following equations (2) and (3), respectively:
• [SiO2]=([SiEDS]×60)/28 (2)
• [F]=([FEDS]×64)/38 (3)
• wherein:
• SiEDS and FEDS are the weight % of Si and F obtained by EDS, 60 is the molecular weight of SiO2, 28 is the atomic weight of Si, 64 is the molecular weight of CH2═CF2, and 38 is the atomic weight of two F elements.