Investigation of electron and phonon transport in Bi-doped CaMnO3 for thermoelectric applications

•The strongly correlated nature of CaMnO3 manifests in the breakdown of the Wiedemann-Franz law, which could be beneficial for thermoelectric applications.•Bi-doping in CaMnO3 exhibits superior thermoelectric properties over the pristine CaMnO3 due to the lower thermal conductivity and electronic resistivity.•Bi-doping adds more phonon scattering path via anharmonicity and increases atomic average mass to decrease thermal conductivity and enhance the thermoelectric figure of merit.