The first commercial application of lithium-ion capacitors developed by Maxwell Technologies in conjunction with China Railway Rolling Stock Corp., one of China's largest rail manufacturers, is underway. The technology will be used for rapid energy regeneration in the trolley system in the capital city of the Hunan province in China.

The capacitors will serve as the single source of power.The capacitors will serve as the single source of power.The capacitors will serve as the single source of power for instant charging and discharging to propel the trolley. Lithium-ion capacitors can charge light rail vehicles in 30 seconds and keep them going for five to 10 minutes. This enables the trolley to restart quickly in stop-and-go traffic. The technology reportedly fulfills China's rail requirements for energy savings and environmental protection.

Maxwell's lithium-ion capacitors combine ultracapacitors' high power density with lithium-ion batteries' high energy density for onboard energy storage systems. The company says that, compared to traditional ultracapacitors, lithium-ion capacitors triple energy density and reduce the total weight of the energy storage system by 50%.

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