HEAT EFFECTS IN BATTERIES AND ULTRACAPACITORS

摘要

Sources of heat effects in batteries, ultracapacitors, and battery-ultracapacitor hybrids are analyzed in this article on a theoretical basis. Also reported are the results of electrochemical calorimetric measurements which precisely quantify the heat effects in relationships with the electrical energy generation. These electrochemical calorimetric measurements have proven that ultracapacitors generate much less heat than batteries do under identical power delivery conditions. An explanation is offered on the basis of the fundamentally different energy storage and delivery mechanism of these devices. Due to the high efficiency of the ultracapacitors, the hybrids may have 30% higher efficiency and extended use time compared with batteries alone in pulse power applications (e.g., portable telecommunication devices and EV propulsion systems). Because of its unique measuring capabilities, the electrochemical calorimeter could play an important role in the development of ultracapacitors and hybrid sources, as well as in the design of thermal management.