Abstract: Provided are a non-aqueous electrolyte, a secondary battery, a battery module, a battery pack, and an electrical device. The non-aqueous electrolyte includes orthocarbonate, chain carbonate, cyclic carbonate, and lithium salt, a mass content of the orthocarbonate is 10% to 80%, and at least one of the chain carbonate or the cyclic carbonate is fluoride. A central carbon atom of the orthocarbonate is bonded to four oxygen atoms, each of which is further bonded to an alkyl or halogenated alkyl chain, which plays an electron attraction role for lone pair electrons of the oxygen atoms, and increases steric hindrance surrounding the oxygen atoms, weakening the capability of the oxygen atoms in binding to lithium ions, and facilitating SEI film formation dominated by anion decomposition.

Abstract: Provided is an electrolyte, including a first solvent represented by formula I and a second solvent selected from one or more of formula II and formula III, where R1 is selected from C1-C6 fluoroalkyl; R2 is selected from a hydrogen atom, C1-C6 alkyl or C1-C6 fluoroalkyl; n represents 1 or 2; and R3 to R10 are each independently selected from a hydrogen atom, a fluorine atom, C1-C6 alkyl, or C1-C6 fluoroalkyl. The electrolyte of the disclosure can improve cycle stability and safety of the battery. A secondary battery including the electrolyte, a battery module, a battery pack, and an electrical device are also disclosed.

Abstract: A composite electrolyte, including a sulfide electrolyte, a polymer electrolyte, and a functional additive material are provided. In some embodiments, the functional additive material is selected from polymers represented by the following structural R1—O—R2-A. In some embodiments, R1 is selected from at least one of polyvinyl group, polypropylene group, polyacrylate group, polyvinylcarbonate group, polyacrylonitrile group, and polystyrene group; R2 is a straight-chain or branched alkyl group with 3-10 carbon atoms; A is selected from at least one aromatic hydrocarbon group of benzene group, biphenyl group, triphenyl group, naphthalene group, anthracene group, phenanthrene group, and pyrene group; and X is selected from at least one of hydrogen atom, halogen atom, mercapto group, hydroxyl group, amine group, and aldehyde group.

Abstract: A composite electrolyte, including a sulfide electrolyte, a polymer electrolyte, and a functional additive material are provided. In some embodiments, the functional additive material is selected from polymers represented by the following structural R1—O—R2-A. In some embodiments, R1 is selected from at least one of polyvinyl group, polypropylene group, polyacrylate group, polyvinylcarbonate group, polyacrylonitrile group, and polystyrene group; R2 is a straight-chain or branched alkyl group with 3-10 carbon atoms; A is selected from at least one aromatic hydrocarbon group of benzene group, biphenyl group, triphenyl group, naphthalene group, anthracene group, phenanthrene group, and pyrene group; and X is selected from at least one of hydrogen atom, halogen atom, mercapto group, hydroxyl group, amine group, and aldehyde group.