  Solid ionic conductors are essential components of batteries and fuel cells.
In many cases, ionic conduction through crystalline materials with
substitutional disorder can be modeled with atomic-scale lattice model
percolation simulations. The ionic percolation theory reviewed in this chapter
describes the percolation behavior of diffusion pathways, identifies the
fraction of lattice sites that contributes to ionic conduction, and quantifies
the tortuosity of diffusion networks. These quantities can be related to the
bulk diffusivity and capacity of intercalation battery electrodes. We discuss
applications to lithium-ion battery cathodes in the disordered rocksalt and
related crystal structures, showing how the diffusion pathways and their
tortuosity vary with the Li content short-range order. All examples are based
on the free and open-source Dribble simulation software.
