China Electric Power News: How do you think about the application of supercapacitors in new energy vehicles? 

Li Weidong: In 2014, hybrid electric buses saved gasoline by up to 35% and even a higher percent. In the same year, the load of each capacitor of TIG was higher than the load of over 5,000 buses. Believe that by 2020 when the subsidies for new energy vehicles are fully withdrawn, the hybrid power with supercapacitors will be popular in markets for its excellent effects for energy conservation and emission reduction, safer and more reliable performances as well as lower costs. 

For start and stop of passenger vehicles (including mild hybrid), supercapacitors have been used in foreign vehicle brands such as mazda for more than a decade. High-end vehicle brands, including Mercedes-Benz, BMW, Audi, Hongqi and Volvo, have launched similar models over the past 5 years. The market responses of these models are favorable. All these are noteworthy for us in the post-subsidy era. In particular, they are suitable for application scenarios of lithium-ion supercapacitors with higher energy density. 

China Electric Power News: Recently, supercapacitors have been greatly favored for regulating power storage frequency. What do you think about this? 

Li Weidong: TIG has engaged in the power storage industry for eight years. We think that our company has absolute advantages in safe and reliable supercapacitors. Calculated based on comprehensive costs of power storage systems in their life cycles, supercapacitors are more cost-effective than batteries. On the premise that only a limited amount of investments are made in the initial stage, hybrid energy storage with “batteries+capacitors” is the best option. A consensus has been reached in the industry to prolong service life of batteries with heavy-power pulse of energy-adsorption systems of supercapacitors. At present, TIG has cumulatively carried out 6 demonstration projects on “batteries+supercapacitors”. 

To increase energy density of power storage systems of supercapacitors, TIG is dedicated to research and persistent development of lithium-ion supercapacitors and energy-based supercapacitors. In addition, it has launched series of lithium-ion supercapacitors with an energy density up to 20 to 80Wh/kg. These supercapacitors can widely satisfy needs for power storage and power needs for frequency and peak regulation of new energy power generation. 

China Electric Power News: What difficulties have you encountered in promoting supercapacitors? How to overcome the difficulties? 

Li Weidong: There are two main difficulties as follows: One is that customers often ask “how much is the cost per kilowatt hour of power?” Supercapacitors, as high-power energy storage devices, are widely known for their inherent exceptional power characteristics, resistance to low temperature and long cycle life. However, low energy density leads to higher cost per kilowatt hour of power. Supercapacitors are not promoted as widely as lithium batteries, so only if their costs are lowered to a certain extent can supercapacitors become popularized. 

The other difficulty is about compatibility of industry standards. Supercapacitors are specific to scenarios of power compensation, voltage stabilization, frequency regulation and maintenance-free standby power supply. However, many present industry standards are still the same as those adopted in the era of lead-acid batteries. Due to low power density, the supercapacitors are “compulsorily” over configured with battery energy that can be used as “standby power supply” for several hours. These standards are rarely compatible with the main needs for power quality in a new era, including transient voltage drop, short-duration voltage variations and maintenance-free. 

Therefore, it is urgent for acceleration and supercapacitor industries to jointly promote establishment and optimization of industry standards. For the sake of industry promotions, we suggest collaborating with potential users, manufacturers of raw materials, the upstream and downstream of the industry chain to build industry clusters or industrial parks to increase vitality of domestic industrial chain of capacitors, and reduce costs of materials and system integration. 

China Electric Power News: What about the development trends of supercapacitors over the past years? What are the optimal application scenarios of supercapacitors? 

Li Weidong: The annual costs of supercapacitors are increasing faster and faster. Their application scenarios are being expanded in markets, and emerging application markets are being constantly developed. Markets are accumulating energies to make quantitative breakthroughs. I would like to say that lithium batteries and supercapacitors are complementary to each other. As a whole, supercapacitors exhibit the greatest potential in second-level, high-power, maintenance-free and low-temperature application scenarios. For instance, these application scenarios include second-level standby high-power UPS (uninterruptible power supply), second-level power supply for starting vehicle engines with thousands of amperes of current, frequently used energy-saving supercapacitor power supply for high-speed capacitors, standby power supply for power grids with long service life, and supercapacitor power supply for micro-grid energy storage adsorbed at second-level pulsed power and so on. 

China Electric Power News: What plan does TIG have for development of supercapacitors? 

Li Weidong: TIG will focus on increasing inherent technological advantages of its supercapacitors, enriching product specifications, and expanding market applications of supercapacitors in high-power start-stop systems dependent upon core supercapacitor technologies. Concerning technological research and development, we will strengthen our research and development of supercapacitors with high energy density. For example, we will increase voltage of electrical double-layer supercapacitors and energy of lithium-ion capacitors. We will launch supercapacitors with a capacity of 1F~30,000F and a voltage of 4V. As to marketing and application expansion, we will concentrate on applications of supercapacitors in vehicle energy conservation and emission reduction, electrical energy storage, intelligent power grids, standby power supply for wind power generation, energy feedback for rail transit, military high-voltage start-stop systems, automatic guided vehicles (AGV) for logistics, and advanced intelligent manufacturing.