▎ 摘　　要

NOVELTY - A composite material comprises inorganic particles, a fluorinated compound (I), and optionally a polymer. USE - Composite material used in solid electrolyte in electrochemical cell such as electrochemical accumulator such as lithium battery and lithium-ion battery used in mobile device e.g. mobile phone, camera, tablet, laptop, electric or hybrid vehicle, and storage of renewable energy (all claimed). ADVANTAGE - The composite material provides electrochemical cell has excellent electrochemical stability, capacity, and columbic efficiency. DETAILED DESCRIPTION - A composite material comprises inorganic particles, a fluorinated compound of formula (I), and optionally a polymer. R ,R =linear or branched 1-8C alkyl, 3-8C cycloalkyl, 6C aryl, 3-8C heterocycloalkyl, or 5-6C heteroaryl (all optionally substituted), in which at least one of R and R is group substituted by fluoro; X =O or NH or absent; X =C(O), S(O) , or Si(R R ) or absent;and R ,R =linear or branched 1-8C alkyl, in which at least one of R and R is group substituted by fluoro. INDEPENDENT CLAIMS are included for the following: an electrochemical cell, which comprises a negative electrode, a positive electrode, and a solid electrolyte. The positive electrode, the negative electrode and the electrolyte each comprises the composite material; and preparation of the composite material, which involves mixing the inorganic particles, the fluorinated compound, and optionally the polymer.