Rechargeable Battery and Electrolysis Method of Making the Same

Abstract

A block or graft copolymer coated lithium metal electrode provides the negative electrode and the solid electrolyte for a rechargeable lithium metal battery that further includes a positive electrode. Optionally, the positive electrode includes elemental sulfur in a conductive matrix. The copolymer coated lithium metal electrode may be manufactured by a process involving electroplating lithium metal through a copolymer coated conductive substrate, for which the copolymer coated conductive substrate has been prepared by coating the conductive substrate in a copolymer solution followed by evaporating the solvent. Alternatively, a lithium metal electrode may be coated directly with copolymer. Rechargeable lithium batteries according to embodiments of the invention have improved cycle life and combustion resistance compared to lithium metal batteries manufactured by conventional methods.

Description

TECHNICAL FIELD[0001]The present invention relates to the manufacture of lithium metal rechargeable batteries using polymeric solid state electrolytes. The resultant batteries are safer and have increased cycle life compared to lithium metal batteries manufactured by conventional methods.BACKGROUND ART[0002]Lithium ion batteries (LIBs) dominate the lithium battery market. LIBs contain no metallic lithium present as such. The negative electrode comprises a carbon host for neutral lithium which is contained therein. In the electrolyte and in the positive electrode lithium is present only as the ion. Such batteries are attractive for their high energy density compared to that of other rechargeable batteries and for their ability to operate over multiple charge / discharge cycles. In lithium metal batteries (LMBs) by contrast the negative electrode comprises metallic lithium, just as in lead-acid batteries the negative electrode comprises metallic lead. During discharge of an LMB, lithium...

AI Technical Summary

Benefits of technology

The patent describes a new type of rechargeable battery that uses a solid electrolyte and a layer of lithium metal. The battery can change its shape to accommodate changes in the lithium metal layer during charging and discharging. This design allows for a thicker and more stable battery that can withstand longer use. The technical effect of this patent is to create a rechargeable battery with a solid electrolyte that can be charged and discharged many times without losing its performance.

Problems solved by technology

Moreover, since LMBs can be manufactured in the fully charged state, they do not require the lengthy formation process needed for LIBs However, poor cycle life, volumetric expansion, and safety concerns relating to shorts resulting from dendrite formation and the potential for violent combustion of the flammable organic electrolytes used in LMBs have limited their practical use as rechargeable batteries.

However, complex polysulfide species produced upon the reduction of elemental sulfur are soluble in the organic electrolytes typically used in lithium batteries, resulting in reduced cycle life due to the “polysulfide shuttle” effect.

Images