Abstract: An electrolyte solution containing a compound represented by formula (1) and a compound represented, for example, by formula (11-1), the formula (1) being: wherein M101 is P or P?O; R101 is a group such as a C1-C11 alkylsilyloxy group; n101 is an oxidation number of M101 minus 1 or an oxidation number of M101 minus 3; and R102 to R104 are each individually a group such as a C1-C11 alkyl group; the formula (11-1) being: wherein R111 and R112 are the same as or different from each other and are each an atom or group such as a hydrogen atom; and R113 is a group such as an alkyl group free from a fluorine atom.

Abstract: An electrode for a rechargeable lithium battery, the electrode comprising an electrode active material layer comprising an electrode active material that is in physical contact with or mixed with a quasi-solid or solid-state electrolyte, wherein the electrolyte comprises a polymer, which is a polymerization or crosslinking product of a reactive additive (reactive liquid electrolyte) comprising (i) a first liquid solvent that is polymerizable, (ii) an initiator and/or curing agent, (iii) a lithium salt, and (iv) an optional second liquid solvent; wherein the first liquid solvent occupies from 1% to 99% by weight and the second solvent, if present, occupies from 0.1% to 99% by weight based on the total weight of the reactive additive; wherein the first liquid solvent has a lower flash point, a higher vapor pressure, a higher dielectric constant, or a higher solubility of the lithium salt as compared with the second liquid solvent.