Patent ID: 11862765
Assignee: THE SCHOOL CORPORATION KANSAI UNIVERSITY
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 0:
1. An alkali metal-sulfur-based secondary battery comprising a positive electrode, a negative electrode, and an electrolyte solution,
the positive electrode containing a carbon composite material that contains a carbon material having a pore volume ratio (micropores/mesopores) of 1.5 to 3.0, and a sulfur-containing positive electrode active material containing simple sulfur,
the electrolyte solution containing a fluorinated ether represented by the following formula (1):

R11—(OR12)n11—O—R13, wherein R11 and R13 are the same as or different from each other, and are each an alkyl group optionally containing a fluorine atom, with at least one of R11 or R13 containing a fluorine atom; R12 is an alkylene group optionally containing a fluorine atom; and n11 is 0, 1, or 2,
wherein the electrolyte solution further contains at least one selected from the group consisting of a fluorinated saturated cyclic carbonate, a fluorinated acyclic carbonate, and a fluorinated ester,
the fluorinated saturated cyclic carbonate is represented by the following formula (2):, , wherein R21 to R24 are the same as or different from each other, and are each —H, —CH3, —F, a fluorinated alkyl group optionally containing an ether bond, or a fluorinated alkoxy group optionally containing an ether bond, with at least one of R21 to R24 being —F, a fluorinated alkyl group optionally containing an ether bond, or a fluorinated alkoxy group optionally containing an ether bond,
the fluorinated acyclic carbonate is represented by the following formula (3):, , wherein R31 and R32 are the same as or different from each other, and are each an alkyl group optionally containing an ether bond and optionally containing a fluorine atom, with at least one of R31 or R32 containing a fluorine atom, and
the fluorinated ester is represented by the following formula (4):, , wherein R41 and R42 are the same as or different from each other, are each an alkyl group optionally containing an ether bond and optionally containing a fluorine atom, and optionally bind to each other to form a ring, with at least one of R41 or R42 containing a fluorine atom,
wherein the alkali metal-sulfur-based secondary battery exhibits a single main discharge plateau on and after the second cycle, and a reaction accompanied by Li2S8 represents 5% or less of all discharge reactions.