Efficient Harvesting Waste Heat by Zn‐Ion Battery Under Thermally Regenerative Electrochemical Cycles

is achieved in NiHCF/Zn battery, leading to a high thermal-to-electrical conversion efficiency of 26.08% of the Carnot efficiency and an extraordinary energy efficiency of 104.11% when the battery is charged at 50 °C and discharged at 5 °C. This work demonstrates that thermally regenerative electrochemical batteries can effectively harvest waste heat to provide a powerful energy conversion technology.