Amorphous cathode material for battery device

A method of fabricating a solid state battery device, the method comprising:

• providing a substrate;
• forming a polymer containing barrier material on the substrate configured to avoid migration of an active metal species to the substrate, and having a barrier degrading temperature;
• forming a layer of first electrode material overlying the substrate;
• forming a layer of amorphous cathode material overlying the layer of first electrode, the layer of amorphous cathode material having a thickness ranging from 0.005 μm to 1000 μm and comprising a plurality of pillar structures, each of the pillar structures having a base region and an upper region, and each pair of pillar structures having a plurality of irregularly-shaped polyhedral structures provided between the pair of pillar structures;
• forming an electrolyte layer overlying the layer of amorphous cathode material;
• forming a layer of anode material overlying the layer of electrolyte;
• forming a layer of second electrode material overlying the layer of anode material;
• and
• providing a thin film solid state battery device characterized by an energy density ranging from 50 Watt-hour/liter to 3000 Watt-hour/liter.