Supercapacitor batteries are new energy storage devices with high energy density and high power density. The research on their anode materials is mainly focused on carbon materials. The working principle of carbon anodes for supercapacitor batteries was analyzed. The preparation methods and electrochemical properties of activated carbon/graphite composites and three-dimensional carbon materials used as anodes for supercapacitor batteries were reviewed. The current carbon materials for supercapacitor batteries were analyzed. The shortcomings in the research point out that the research focus of carbon anode materials for supercapacitor cells should focus on the in-depth study of its energy storage mechanism. The study of the relationship between the structure and properties of carbon materials using quantum chemical calculation methods is also a focus of future research.
The so-called super capacitor can be understood as an electrolytic capacitor with an excessive capacity. However, the use of this capacitor is very different from the past, it is used as a battery. The capacitance of super capacitors is usually above 1F. Compared with the hundreds of thousands of uF electrolytic capacitors commonly used in circuits, the capacity is 1000 times larger and the operating voltage ranges from 1.5V to 160V or even higher. As the capacitance value and voltage increase, its volume also increases. Early supercapacitors with capacitance values around tens of farads were large, mainly used for large power supplies. Small-capacity supercapacitors with low-voltage operation are often used as short-term backup power supplies in consumer electronics (relative high-end UPS). With the recent advances in technology, when the operating voltage of a supercapacitor is increased to 25Vdc, the volume is less than doubled, which means that the device has better capacitance properties. However, the application of supercapacitors is not easy. As early as 2006, there were trials of batteries with supercapacitors in Shanghai, but the failure rate was extremely high. Only one of the 7 cars in a week was still in normal. Work, which makes the super capacitors really enter the car market is forced to slow down.
After development in recent years, the volume of supercapacitors has become smaller and smaller, the quality is more and more stable, and the performance is more and more like a battery. At present, super capacitors above 5F have begun to be used in many portable and handheld products, and some even replace batteries. In the automotive field, it is developing rapidly. Due to factors such as short charging time and environmental protection of electrolyte materials, many manufacturers have high hopes for supercapacitors as a source of electric energy for hybrid vehicles. It is hoped that supercapacitors will be transferred from concept cars to general vehicles as soon as possible.
Recent data from the Massachusetts Institute of Technology lab show that in the next few years, the energy storage capacity of supercapacitors will have a qualitative leap. Current supercapacitor products discharge 10 times faster than conventional batteries, while energy storage capacity is only 50% of the latter under the same volume. This unfavorable situation will be reversed in the next few years. By then, supercapacitors will truly enter a broader application area.