Progress and prospects for low-grade heat recovery electrochemical technologies

The low-grade heat is ubiquitous and widely distributed. Due to the lack of efficient recovery methods, the low-grade heat is directly discharged into the environment, causing energy waste. The low-grade heat recovery electrochemical devices have advantages of simple structure, low cost of materials, environmental protection, and ideal electrical energy output and thermal-electrical conversion performance. The latest progress of low-grade heat recovery electrochemical technologies (including thermally regenerative electrochemical cycles, thermally regenerative ammonia batteries and liquid thermo-electrochemical cells) is reviewed. By analyzing the problems that need to be solved in the current stage of the electrochemical systems, suggestions for the future research focus and development directions of low-grade heat recovery electrochemical technologies are proposed.