  Solid-state batteries (SSBs) have recently been proposed as promising
alternatives to conventional Li-ion batteries because of their high level of
safety and power density. The engineering of SSBs requires comprehensive
modeling of their physics and electrochemistry with an emphasis on the
interfacial processes, including electrochemical stability and mechanical
stresses. In this article, continuum-scale simulations are chosen as the
modeling framework to study such properties. A comprehensive continuum model is
constructed for the simulation of the electro-chemo-mechanical (ECM) response
of an SSB that resolves the bulk transportation of charged species and their
interfacial transfer kinetics. It also studies the formation of space charge
layers (SCLs) at interfaces and the development of interfacial stresses. The
results suggest that the SCLs and the charge transfer kinetics are intertwined.
The emergence of the SCLs and the depletion of reactants increases the charge
transfer overpotential. We have also studied the coupling between
electrochemistry and mechanics at interfaces, the results of which indicate
that the strong electric fields originating at interfaces yield significant
stresses. We, thereby, highlight the necessity of considering the ECM coupling
in the SCLs when modeling an SSB.
