In some embodiments, the first electrochemical fluid in the first channel is separated from the second electrochemical fluid in the second channel by an ion-transfer membrane creates an electric potential between the first electrode(s) position in the first channel and the second electrode(s) positioned in the second channel. In some embodiments, both the first die and the second die have electrodes positioned in contact with one or more of the first electrochemical fluid and the second electrochemical fluid. The first die and second die can, therefore, both receive electrical power from the electrochemical fluids while the electrochemical fluids receive heat from the first die and second die to exhaust the heat therefrom. In some embodiments, the heat transfer structures further transfer heat to the electrochemical fluids. In some embodiments, at least one of the ion-transfer membranes is a heat transfer structure.