Energy safety and environmental concerns make improving the efficiency of vehicle systems a hot research object. This paper summarizes and compares the efficiencies of vehicle powertrain systems in various energy sources, such as internal combustion engine, pure electric, fuel cells and hybrid systems. With the advancement of combustion technology, high-pressure common rail fuel injection system, hybrid and other technologies, the thermal efficiency of the internal combustion vehicle powertrain has been increased from 30% in 1960 to current about 50%. However, the challenge of continuing to improve the thermal efficiency of internal combustion engine-based powertrains will grow. At present, the transportation industry is focusing on pure electric and hydrogen-fueled proton exchange membrane fuel cell (PEMFC) powertrains, and has made progress in industrialization. Pure electric powertrans, due to the battery’s own weight and charging rate problems, limit its application in the long-distance freight market space. Hydrogen fuel cells still have great challenges in hydrogen storage and transportation. This paper points out that the metal support solid oxide fuel cells (SOFC) has the advantages of energy diversification and high energy conversion efficiency. In recent years, the third generation of metal-supported SOFC have also improved their start-up duration, start-up times and durability. With the further improvement of its power density and fast start performance, the industrialization of efficient solid oxide fuel cell vehicle powertrans will become a reality in the future.
