Will graphene help supercapacitors replace lithium batteries?

Compared with lithium batteries, supercapacitors have fast charging and discharging speed, high efficiency, long cycle life and high safety. These seem to be the antidote to the current dilemma of electric vehicle promotion. When the lithium battery industry is enjoying the chasing of the stars and the moon, one of its potential opponents has quietly approached, and it is the super capacitor. Recently, market research firm IDTechEx made a bold assertion that supercapacitors will destroy the lithium-ion battery market.

In a report titled 'Supercapacitor Market 2014-2024', IDTechEx stated that by 2024, the global supercapacitor market will be worth $6.5 billion, and the market share will increase while swallowing the battery market. The so-called supercapacitor is a new type of energy storage device between traditional capacitors and rechargeable batteries. The basic principle is the same as that of other types of electric double-layer capacitors. The electric double-layer structure composed of activated carbon porous electrodes and electrolytes is used to obtain super-large capacity. Because of its large capacity, its external performance is the same as that of batteries, so it is also called 'capacitor battery'.

Why do some people think it will replace lithium batteries? Mainly from its performance considerations. Compared with lithium batteries, supercapacitors have fast charging and discharging speed, high efficiency, long cycle life and high safety. These seem to be the antidote to the current dilemma of electric vehicle promotion. The world's first supercapacitor 100% low-floor tram, delivered in a single batch by CSR Zhuji in May this year, uses 7500F electric double-layer supercapacitors with a lifespan of 10 years and can be charged and discharged 1 million times. The train can be quickly charged every time it enters the station, the maximum charging time is 30 seconds, and the fastest charging can be completed in 10 seconds. The safety performance of supercapacitors higher than that of lithium batteries has also been demonstrated in various events in recent years.

In the past year, Boeing, Apple, Tesla and other companies have been trapped in the safety of lithium batteries, causing frequent incidents. Experts also pointed out that lithium batteries are 'inherently difficult to move', and it is difficult to technically make up for their safety shortcomings. The supercapacitor itself, which uses electrostatic charge to store electrical energy, ensures its safety performance. Today, supercapacitors mainly play a supporting role in lithium batteries due to their low energy density.

However, due to the application of 'universal material' graphene, the footsteps of supercapacitors to replace lithium batteries seem to be getting closer. Although there are many debates at home and abroad, no consensus has been reached. However, compared with the high enthusiasm for lithium batteries in China, the approach of many European and American countries is more balanced. Taking Germany as an example, the 'German National Electric Vehicle Development Plan' promulgated in 2008 places the research and development of supercapacitors and lithium batteries on the same equal position.

In the industrialization of supercapacitors, some companies in the United States, Japan, Russia, Switzerland, South Korea, and France are currently in a leading position with years of research and development and technology accumulation. Such as Maxwell in the United States, Nec, Panasonic, Tokin in Japan and Econd in Russia, etc., these companies currently occupy most of the global market.

Among them, Maxwell was the first to taste the big cake from the Chinese market. According to Alexander Potter, an analyst at PiperJaffray, an American investment bank, Yutong is currently Maxwell's largest customer, and the order growth is still accelerating. In recent years, some Chinese companies have also begun to actively set foot in this industry due to their optimism about the broad application prospects in this field. However, due to the high technical barriers, before 2012, there were more than 50 domestic manufacturers engaged in the research and development of large-capacity supercapacitors, but only more than 10 manufacturers were able to mass-produce and reach the practical level.

However, given that supercapacitors can be used in various industries such as new energy power generation, smart grids, new energy vehicles, energy-saving buildings, industrial energy conservation and emission reduction, whether or not they will replace lithium batteries in ten years, its use determines its strategic value. .