Solvent-free solid electrolyte for applications in lithium-ion batteries and lithium-ion secondary batteries

摘要

The invention relates to a solvent-free polymer electrolyte for use in a rechargeable lithium ion secondary battery, comprising a lithium-ion conductive polymer matrix and a lithium salt. The polymer matrix comprises at least one polyrotaxane comprising at least one linear polymer and at least one ring-shaped molecule. The lithium salt is disposed in the polymer matrix and at least partially chemically bonded to the polymer matrix. According to the invention, the polymer matrix comprises at least one polyrotaxane with a wholly or partially chemically modified cyclodextrin or crown ether as a ring-shaped molecule. The structural change causes a greatly increased ionic conductivity, in particular at room temperature. Furthermore, the chemically modified systems according to the invention show improved electrochemical stability For industrial applications, stable long-term cyclization, which is indispensable for industrial applications, can be realized reproducibly by means of the newly developed dry polymer electrolytes in lithium / LiFePO cells at high charge and discharge currents (≥ 1 C).