This model accounts for the fact that the surface temperature of a cell in a thermal chamber is typically different from the "set"/"ambient" temperature of the chamber.

Suggested steps to do this below, but open to discussion:

• Add a submodel SurfaceAmbientTemperature which sets surface temperature equal to ambient temperature
• Add another submodel SurfaceTemperatureODE which implements the equation from Mohan et al:

• In that submodel, register a citation for that paper
• In all other thermal submodels, replace "ambient temperature" with "surface temperature"
• In BaseBatteryModel, add an option for "surface temperature" which can be "ambient" (default) or "ODE", then add an if statement for selecting the appropriate model
• Add a test for selecting the "ODE" option
• Add docs