Graphene helps supercapacitors break through the energy density bottleneck

Recently, the new graphene-based high-energy lithium-ion capacitor technology developed by the Qingdao Energy Storage Institute of the Chinese Academy of Sciences passed the expert appraisal and evaluation organized by the China Petroleum and Chemical Industry Federation in Beijing. Experts agree that the achievement is highly innovative, and it is recommended to promote the industrialization process as soon as possible.

The Energy Storage Institute designed and constructed the first pilot production line of lithium-ion capacitors in China, and developed the highest capacity 3500F/4V lithium-ion capacitor monomer. As a new type of energy storage device, supercapacitors have the advantages of high power density, short charging time, and long life, but their energy density has always been limited by the performance of electrode materials.

The graphene supercapacitor developed this time has an energy density of up to 80 Wh/kg (specific energy) at a power density of 1 kW/kg (specific power), which is much higher than the current commercial activated carbon-based supercapacitors. The graphene-based supercapacitor has broad application prospects in high-power/high-energy-density dynamic energy storage devices.

Considering that the energy storage device takes into account high power and high energy density, fast charging and fast discharging, it is very suitable as an 'energy bucket' for energy Internet technology. Based on this 'energy bucket', Qingdao Energy Storage Institute is building a small near-zero carbon emission demonstration area. At the beginning of 2015, Qingdao Energy Storage Institute used this device to build a 48V system for demonstration applications in electric vehicle power supply and other aspects. Recently, Qingdao Energy Storage Institute is striving to use this technology in the field of rail transit as soon as possible.

According to statistics from IDTechEX, the global market for supercapacitors in 2014 was US$1.1 billion. It is estimated that by 2018, the global market size of supercapacitors will reach 3.2 billion US dollars, with a compound annual growth rate of 31%. Supercapacitor applications include electronic products, new energy, new energy vehicles, transportation, etc.

In 2013, the size of China's supercapacitor market increased from 700 million yuan in 2009 to 1.92 billion yuan, with an annual growth rate of 32.51%. It is estimated that by 2016, the size of China's supercapacitor market will reach 3.38 billion yuan, with an annual growth rate of 22.08%.