  We establish weak-strong uniqueness and stability properties of renormalised
solutions to a class of energy-reaction-diffusion systems, which genuinely
feature cross-diffusion effects. The systems considered are motivated by
thermodynamically consistent models, and their formal entropy structure allows
us to use as a key tool a suitably adjusted relative entropy method.
Weak-strong uniqueness is obtained for general entropy-dissipating reactions
without growth restrictions, and certain models with a non-integrable diffusive
flux. The results also apply to a class of (isoenergetic)
reaction-cross-diffusion systems.
