Context

The aim of this invention is to replace usual liquid electrolytes (organic solvent and lithium salts) by solid electrolytes and to produce an all solid state battery.

The difficuly in manufacturing all-solid state batteries consists in sintering together ceramic electrodes and electrolyte materials without generating reaction between these materials.

TECHNICAL DESCRIPTION

This invention relates to a one-step assembly of an all solid state battery by a Spark Plasma Sintering process.

Two different mixtures are prepared:

Mixture 1: anode active material powder, electrolyte solid powder and an element improving the electronic conductivity

Mixture 2: lithium based cathode active material powder, electrolyte solid powder and an element improving the electronic conductivity

The assembly of the battery is made by superposition of a layer of mixture 1 and a layer of mixture 2 which are separated by an electrolyte powder layer. The three layers are sintered together in appropriate conditions.

BENEFITS

Advantage of the process used in this invention:

– Quick and easy to implement;
– No secondary  reaction between the elements of the different layers;
– One step process;
– Benefits of the battery obtained with this process;
– Self-supported;
– Electrode layers are thicker than in all-solid state batteries available so far;
– Good electronic conductivity properties;
– Good thermal stability (up to 350°C)

INDUSTRIAL APPLICATIONS

This invention can be used to the manufacturing of « voluminous » all solid-state electrochemical generators (contrary to microbatteries).