All-solid-state silver batteries assembled by Spark Plasma Sintering

Bulk-type Ag0.7V2O5//Ag6I4WO4//Ag0.7V2O5 all-solid-state batteries have been assembled in one step by Spark Plasma Sintering (SPS). Their electrochemical performances were compared to the ones of similar solid state cells assembled by cold pressing, as reported in the 90s. The cold-pressed all-solid-state batteries with thick composite electrodes (above 400 μm) display poor electrochemical properties explained by an important cell polarization associated to poorly defined electrode/electrolyte interfaces. In contrary, the thick batteries obtained by SPS exhibit excellent reversibility without any need of pressure load during cycling. The behavior lies on the well-defined interfaces and a good mechanical aspect, which are kept upon cycling. During the charge/discharge cycles, the electrochemical formation of AgxV2O5 does not display a drastic volume change, preserving the electrode/electrolyte interfaces. The structural evolution of AgxV2O5 upon cycling is discussed in comparison to the known phases synthesized by solid state reactions. The obtained results on silver batteries allow a general reflection on the development of all-solid-state Li-ion technology by SPS.