The problems or issues faced by typical larger SSE batteries are solved by providing an interface or interfacial layer at least between the
anode, which comprises Li or Na, and the
solid state
electrolyte (SSE). In some other embodiments, an interfacial layer may be provided between the
anode, which comprises Li or Na, and the SSE, and an interface or interfacial layer may also be provided between the
cathode and the SSE. In at least selected embodiments, aspects or objects, the interfacial layer may act as a
shock absorber between a SSE (e.g., a
sulfide glass SSE) and an
anode material that is soft compared to the SSE (e.g., Li
metal). In other embodiments, the interfacial layer may act as a
shock absorber between the SSE and a
cathode material that is softer than the SSE. In at least certain embodiments, the interfacial layer may improve
ionic conductance between the anode and the SSE and / or the SSE and the
cathode. In at least certain selected embodiments, the interfacial layer may prevent or deter
lithium deposition and
dendrite growth at the interface between the anode and the SSE. Interface defects at the interface between the anode and the SSE may allow
lithium deposition and
dendrite growth. The dendrites may continue to grow through cracks in the SSE causing a short, which is a safety issue. The inventive interfacial layer between the anode and the SSE may prevent or deter this. In at least some embodiments, the interfacial layer may be a porous
polymer layer filled with liquid
electrolyte and may improve
ionic conductance between the anode and the SSE and / or the SSE and the cathode. In certain embodiments, the anode interface or interfacial layer may be a porous
polymer layer filled with liquid
electrolyte. In some embodiments, the cathode interface or interfacial layer may be a porous
polymer layer filled with liquid, gel or polymer electrolyte.