The Guiding Opinions on Promoting Energy Storage Technology and Industrial Development issued recently by the National Development and Reform Commission (NDRC) put forward that related work should be promoted in two stages in the next 10 years, including the transition from R&D demonstration to commercialization during the 13th Five-Year Plan period and the transition from commercialization to large-scale development during the 14th Five-Year Plan period. The advent of energy storage industry guidance indicates that China’s energy storage industry is moving from demonstration projects to commercial applications.

Development Trend and Characteristics of Energy Storage in China

In recent years, energy storage in China has shown a good trend of diversified development: pumped storage is developing rapidly; compressed air energy storage, flywheel energy storage, superconducting energy storage and supercapacitor, lead-acid battery, lithium-ion battery, sodium-sulfur battery, liquid-flow battery and other energy storage technologies have been accelerated; heat storage, cold storage and hydrogen storage technologies have also made some progress.

Energy storage of lithium ion batteries is an important part of electrochemical energy storage. At present, the main energy storage technologies are mechanical energy storage (pumped energy storage, compressed air, flywheel energy storage, etc.), electromagnetic energy storage (superconducting magnetic energy storage, supercapacitor, etc.), and electrochemical energy storage (lead-acid battery, liquid-flow battery, lithium-ion battery, etc.). Among them, pumped storage technology is the most mature and economical energy storage technology with the advantages of large scale, long life and low operating costs. Among the energy storage projects operated in China, the cumulative installed number of pumped storage energy accounts for 99.5%. However, pumped energy storage must have suitable geographic conditions for the construction of upper and lower reservoirs, which are greatly restricted by topographic conditions and have a long construction period.

Lithium-ion battery energy storage is the main form of future development. The electrochemical energy storage technology has the advantages of short response time, high energy density, flexibility and convenience, and low maintenance cost. It is the main energy storage form besides pumped energy storage. It is predicted that the cumulative installed capacity of electrochemical energy storage in China will increase steadily. The cumulative installed capacity in 2016 is 255 MW. By 2020, the installed capacity of electrochemical energy storage will exceed 2000 MW. The compound growth rate in 2016-2020 is close to 70%. The energy storage of lithium ion batteries accounts for 66% of the installed electrochemical energy storage units, which is the main form of electrochemical energy storage.

Lithium battery energy storage cost reduction technology is becoming more and more mature

Lithium-ion batteries are the most common energy storage technology on the market. They are widely used in various personal electronic products, mobile devices and even vehicle-borne batteries for electric vehicles. Usually we refer to lithium-ion batteries, which are generally divided into energy storage lithium batteries and power lithium batteries according to their uses. Energy storage lithium batteries for photovoltaic or UPS have large internal resistance and slow charging and discharging speed, generally 0.5~1C. Power batteries are generally used in electric vehicles, with small internal resistance and fast charging and discharging speed, and can generally reach 3~5C, which is about 1.5 times more expensive than energy storage batteries.

Energy density, power density, safety performance, charging time, high and low temperature of environment resistance are the five major indicators for evaluating the performance of lithium batteries. At present, the last four points of lithium batteries technology in China have initially reached the standard, but in terms of energy density, further refinement of technology is needed, waiting for progress. On March 1, 2017, the Ministry of Industry and Information Technology, the Development and Reform Commission, the Ministry of Science and Technology and the Ministry of Finance jointly issued the Action Plan for Promoting the Development of Automotive Power Battery Industry, which calls for major breakthroughs in key materials and components of power batteries. By 2020, key materials and components such as positive and negative electrodes, diaphragms and electrolytes will reach the first-class level in the world, and the upstream industrial chain will achieve balanced and coordinated development to form innovative backbone enterprises with core competitiveness. The requirement of specific energy for batteries in this scheme will inevitably lead to a new upsurge of high energy density materials.

At present, the hot lithium titanate materials also deserve attention. It can replace graphite as anode material. Although the energy density is not high, lithium titanate can make the battery charge and discharge at high rate, with excellent safety and long cycle life. It is reported that the cost of the fourth generation high energy density lithium titanate battery developed by Yinlong is 40% lower and the energy density is 60% higher than that of the third generation. The industry is optimistic that in the future lithium titanate batteries may be tripartite lithium batteries and lithium iron phosphate batteries.

Although the high cost of lithium-ion batteries is a serious challenge for the development of the industry, many enterprises have been committed to improving the performance-price ratio of lithium-ion batteries. According to Duff (Lv Lishun), an analyst at EnergyTrend, the price of lithium batteries rose slightly in the first, second and third quarters of 2017. Overall, with the continuous expansion of market demand for lithium batteries in recent years, the cost of large-scale production of lithium batteries is declining year by year, and the current price is enough to be commercialized and widely used.

In addition, the power lithium battery can be used in energy storage step by step after its initial capacity is reduced to less than 80%, which further reduces the cost of energy storage lithium battery.

Future Development Prospect and Enterprise Layout

The development of energy storage industry may continue the prosperity of lithium power equipment. The rapid development of new energy automotive industry has led to the rapid progress of lithium-ion battery technology. The cost of lithium-ion battery has gradually decreased, and the energy density is also in the ascending channel. With the further maturity of battery technology and business model of energy storage industry, energy storage industry will usher in rapid development, and is expected to continue the prosperity cycle of lithium-ion equipment.

With the reduction of the cost of lithium batteries and the improvement of energy density brought by battery technology, as well as the further maturity of the business model of energy storage industry, the energy storage industry will usher in rapid development, which is expected to continue the prosperity cycle of lithium-ion equipment.

The development of Kelu Electronics in the field of energy storage is worth looking forward to.

Current Research of Kelu Electronics