Suppliers look to improve their selections, with R&D efforts emphasizing new variants such as pseudocapacitors and hybrid units.

Broadening adoption in the consumer electronics, medical, energy, industrial and vehicle sectors is driving China supercapacitor manufacturers to grow the nascent line. Companies plan to develop pseudo and hybrid types while enhancing mainstream electric double-layer units to match the trends for greater power and energy density, capacitance and reliability.

Product advantages based on the above attributes are accelerating market penetration. Globally, sales are expected to hit $2.1 billion in 2020, achieving nearly 27 percent CAGR from 2013, according to MarketsandMarkets. The largest potential application is the manufacturing segment of the transportation industry, covering buses, trains, aircraft, and electric and hybrid vehicles.

China suppliers such as Shanghai Green Tech Co. Ltd are eyeing the growing EV sector. About 20 percent of the maker's supercapacitors are for electric buses, golf carts and forklifts.

To boost competitiveness in the electric double-layer subcategory, companies ensure better product performance by using electrodes, electrolytes and separators sourced from foreign providers. There are also efforts toward the wider adoption of graphene as electrode material. Carbon and derivatives are commonly employed at present.

Suppliers are conducting R&D for pseudocapacitors, which use metal oxides and conductive polymers. Nantong Jianghai, meanwhile, has released Li-ion hybrid ultracapacitors, which have a higher output voltage compared with electric double-layer kinds. While both have a similar power density, the former surpasses the conventional kind in terms of energy density. The company plans to mass-manufacture the variant this year. So far, it is the only known local maker to venture into this new type.

At present, supercapacitors are still a minority in China's capacitor industry due to the component's relatively higher prices.

With climbing output and production capacity worldwide, quotes are expected to be in a downward trend and bolster demand. As such, domestic companies are confident of fast growth in the line, anticipating a revenue increase exceeding 20 percent in coming years.

As early as end-2015, Shandong Goldencell Electronics Technology Co. Ltd targets about 50 percent greater sales value. It can churn out 30 million coin, 20 million cylindrical and 10 million modular supercapacitors annually.

Shanghai Green looks forward to a 30 percent revenue boost. It plans to double production capacity to 4 million farads per day in 1Q14.

Jinzhou Kaimei Power Co. Ltd can handle 70 million units.

All three suppliers produce electric double-layer kinds only, which are based on activated carbon or derivatives.

The line has about 60 manufacturers in China, spread in Beijing, Shanghai, and the provinces of Liaoning, Heilongjiang, Shandong, Jiangsu, Zhejiang and Guangdong. Shanghai Aowei, Supreme Power and Jinzhou Kaimei are among the large suppliers.

Globally, major players such as Maxwell, Elna, Nesscap, NEC, Panasonic and Elit dominate the category.

See a comparison table of supercapacitor suppliers on GlobalSources.com