The solid electrolyte composition, the solid electrolyte, production method of a lithium ion secondary battery and a lithium ion secondary battery

Lithium ion conductivity and strength at low temperatures to provide good solid electrolyte compositions and solid electrolyte. Further, to provide a method of manufacturing a charge-discharge performance and lithium ion secondary batteries and lithium ion secondary battery is improved strength of the solid electrolyte layer at low temperature. The solid electrolyte matrix has a microstructure in which the non-reactive polyalkylene glycol co crosslinked chemically crosslink the highly branched polymer and crosslinkable ethylene oxide multicomponent copolymer is held. The matrix is ​​dissolved lithium salt. Negative electrode active material layer is a layer obtained by dispersing the negative electrode active material and the conductive additive to lithium-ion conductive solid electrolyte. The positive electrode active material layer is a layer on the lithium ion conductive solid electrolyte by dispersing the positive electrode active material and conductive additive.