Distribution Status of Electrochemical Energy Storage Technology in China

What is energy storage?

Broadly speaking, energy storage, IE energy storage, refers to a cyclic process in which one form of energy is stored in the same or converted into another form of energy through a medium or device and needs to be released in a specific form of energy.

In a narrow sense, energy storage is the storage of electrical energy. It refers to a series of technologies and measures that use chemical or physical methods to store the generated energy and release it when needed.

From the definition we can see that generalized energy storage refers to the storage of all energy, including heat storage and electricity storage. The narrow sense of energy storage refers only to the storage of electrical energy. The "energy storage" discussed in this paper is taken in a narrow sense.

Energy storage technology classification

Storage energy is divided into physical storage energy and chemical storage energy. The technical characteristics of these two are as follows:

Physical energy storage: pumped storage energy, compressed air storage energy, Flywheel storage energy.

Features: Water, air, etc. are used as energy storage media, and no chemical changes occur in energy storage media.

Electrochemical energy storage: lead batteries, lithium-ion batteries, liquid-flow batteries, nickel-metal hydrogen batteries, etc.

Features: Chemical elements are used as energy storage media, and the process of charging and discharging is accompanied by chemical reactions or changes in the energy storage medium.

The difference between physical energy storage and chemical energy storage is whether there is a chemical change in the energy storage medium. Statistics from industry organizations show that from 2000 to 2016, among the various ways of energy storage in China's energy storage market, the water storage capacity accounted for the largest, but the growth was slow. The electrochemical energy storage represented by lithium ion batteries has grown rapidly, accounting for an increasing proportion, and the electrochemical energy storage market has great growth potential.

Electrochemical energy storage market technology distribution

According to the statistics of the "Energy Storage Industry Research White Paper 2017" released by the Zhongguancun Energy Storage Industry Technology Alliance, in 2016, almost all of the electrochemical energy storage projects put into operation in China use lithium-ion batteries and lead storage batteries. The proportion of add-on machines is 62% and 37% respectively.

In 2016, in terms of the year-on-year growth rate of new installed capacity in China, lithium-ion batteries ranked first with a growth rate of 256%. In addition, lithium-ion batteries accounted for the largest proportion of new installed capacity in the field of renewable energy grid connection. Up to 70%; lead storage batteries account for the largest installed capacity in distributed generation and microgrid, accounting for 69%.

From the perspective of the distribution of various technologies, lithium-ion batteries are distributed in all regions, of which the largest proportion is in the Northeast, central China, southern China, Northwest and Southwest; Lead batteries account for the largest proportion in North and East China; Liquid flow batteries are mainly distributed in the Northeast region.

However, from a global perspective, in 2016, the newly launched electrochemical energy storage projects mainly use energy storage technologies such as lithium-ion batteries, sodium sulfur batteries, and lead batteries. The new installed capacity of the three technologies accounts for a total of all new projects. More than 99 % of the installed capacity. From the perspective of growth, the new scale of sodium and sulfur batteries has the fastest annual growth rate of 2,400 %; Followed by lead batteries, the year-on-year growth rate was 563 %.

It can be seen that whether it is the global energy storage market or the Chinese energy storage market, the new installed capacity of lithium-ion batteries ranks first, which reflects the current dominant position of lithium-ion batteries in energy storage technology. Sodium sulfur batteries have many applications abroad, but there are fewer in China; The accumulative installed capacity of lead batteries in domestic energy storage market is already behind lithium-ion batteries, which also reflects the general trend of lithium-ion batteries replacing lead batteries in the energy storage field.

Distribution of Electrochemical Energy Storage Technology

1. Lithium-ion batteries

Lithium-ion batteries have good energy storage performance, long service life and high cycle times. Under normal circumstances, lithium batteries can be recycled about 3,000 times, and lithium titanate batteries are as high as 25,000 times. Lithium-ion batteries have low self-discharge loss and high energy conversion efficiency. Compared with other batteries, they have greatly improved their performance. Through the above, we know that the new installed capacity of lithium-ion batteries ranks first in the world and in China, and many domestic companies have deployed lithium-ion battery storage technology.

Shanghai ZTE Energy Technology Co., Ltd. (hereinafter referred to as ZTE) focuses on the development and production of lithium iron phosphate energy storage systems. The company's lithium iron phosphate battery system has flexible configuration and high reliability. Applied to communication energy storage system, data room, home photovoltaic energy storage system, robot system and high voltage DC energy storage system and other application scenarios.

The German Relzow 100MW/200MWh lithium battery storage power station built by Shenzhen Advanced Clean Power Technology Research Institute Co., Ltd., which is owned by Lions Technology, is mainly used in the German FM market. All power stations use lion technology modular energy storage integration technology and lithium battery products, with rapid response, long service life and other characteristics. At the same time, the project is also the first case in which Chinese companies invest in overseas energy storage projects and participate in power operations.

Zhongtian Storage Energy Technology Co., Ltd.(hereinafter referred to as "Zhongtian Storage Energy") is committed to the layout of the lithium battery energy storage project. In 2016, the capacity of Zhongtian Storage Lithium Battery reached 2GWh, and the power storage system achieved overseas sales. Since 2017, the company has undertaken 3 megawatt energy storage projects and has the total engineering contracting capacity for power storage projects.

Energy storage is one of the main applications of lithium titanate batteries. As of January 2017, Shenzhen Baoqing Battery Storage Station, which uses Yinlong New Energy Lithium Titrate Technology, has been operating safely and steadily for six years. The energy storage station is the first megawatt lithium battery storage station in China, and it is also the National 863 project and the key scientific and technological project of the Southern Grid Company-the "10MW battery storage and storage technology research and pilot" demonstration project. The successful operation of six years indicates that Chinese enterprises have studied and mastered and successfully applied the key technology of megawatt battery energy storage.

In addition, Zhejiang Nandu Power Co., Ltd. and other companies have also deployed the energy storage technology route of lithium iron phosphate.

2. Lead Battery

Lead battery technology is mature, battery materials from a wide range of sources, low cost, its disadvantage is the number of cycles, short service life, in production recovery and other links of improper treatment easy to cause pollution of the environment. The researchers added activated carbon to the negative electrode of the lead battery to form a lead-carbon battery. Compared with ordinary lead batteries, lead-carbon batteries can be filled for 90 minutes, reducing the phenomenon of negative sulfate salinization, extending the battery life, and increasing the power density. Lead carbon battery is a kind of advanced lead battery and is also the mainstream direction of the development of lead battery technology.

The power storage technology route in Nandu is dominated by lead batteries. It is understood that the commercial energy storage plant project of lead-carbon battery technology, which is actively promoted by Nandu Power Supply, has significant economic advantages. It is estimated that under the peak price difference of 0.9 yuan/kWh, the company's annual operating profit per 1 MW storage power station is about 100,000 yuan, and the internal return rate is as high as 11 %.

After many years of precipitation, Shenyang Power has formed a mature lead-carbon battery technology. The FCP lead-carbon battery produced by it has introduced advanced lead-carbon technology and product design and manufacturing experience of Furukawa Battery Co., Ltd. in Japan, and has achieved 70 % of the DOD deep cycle times. More than 4,200 times, design life of 15 years, Applied to new energy access, distributed power generation, smart grid and so on.

Shuangdeng Group is a provider of energy storage micro-network solutions. Currently, it has formed a variety of energy storage applications such as scenery storage micro-grid, peak filling storage power station, scenery diesel-electric hybrid base station power supply system, and border and coastal defense power supply system. Solutions, with serialized, standardized, modular energy storage system products. In the national network Zhangbei scenery storage and transmission demonstration power station, equipped with 12 MWh lead battery storage energy; In the energy storage system of medium and widespecial Qilian Micro-Net, the 28MW tubular colloidal lead-acid battery system acts as the main power source, and cooperates with the lithium battery to achieve the stable operation and energy optimization management of the microgrid.

In addition, lead battery manufacturers include Tianneng Battery and Shanghai Xiendi. These companies 'battery products are widely used in the field of energy storage.

3. Sodium Sulphur Battery

Sodium sulfur batteries are batteries with negative sodium(Na), positive sulfur(S), and electrolytes using fine ceramics. The core barrier is fine ceramic technology. The energy density of sodium sulfur batteries is as high as 760 Wh / kg, the conversion efficiency is close to 100 %, and the number of battery cycles is as high as 2,500. However, the shortage is costly, reaching about $2,000 per kWh; The work environment is demanding, and 300 °C can be started. If there is a short circuit failure, the temperature will be as high as about 2000 °C. Therefore, there are extremely high requirements for technology. There are many applications of sodium and sulfur energy storage batteries abroad and there is no large-scale promotion in China.

In May 2015, Zhoushan Qintang New Energy Technology Co., Ltd. produced sodium and sulfur batteries in Shenzhen. The company's sodium and sulfur energy storage battery field has won a number of practical new inventions, including single-tube sodium and sulfur batteries installed in solid electrolytes. Devices, multi-tube sodium and sulfur batteries installed in solid electrolytes, etc.

On January 18, 2017, Chaowei Group and General Electric Company of the United States held a signing ceremony for the sodium and salt battery project in Changxing, Zhejiang Province. In combination with the industrial and technological advantages of the two sides, they jointly established a joint venture company to expand the application field of sodium and salt batteries. A key step in the beach energy storage market. The two sides will focus on the production, development and sales of sodium salt batteries and build a globally competitive professional company.

In addition, Wuhu Haili Industrial Co., Ltd. has been studying sodium sulfur batteries since the early 1980s. In April 2007, it applied for and obtained a national invention patent for high-power sodium sulfur batteries. At the end of 2009, the National Grid stated that it had developed sodium sulfur batteries that could be used for large-scale energy storage.

4. Fluid battery

The liquid current battery adopts the special structure of the positive and negative electrolytes, which improves the chemical reaction efficiency. The energy conversion efficiency of liquid-flow batteries can reach more than 96 %, the energy density can reach 92Wh / kg, the number of cycles is about 13,000, and the service life is about 20 years. Due to the low technical maturity, large size and low price, liquid-flow batteries are not widely used in China.

Dalian Rongke Energy Storage Technology Development Co., Ltd.(hereinafter referred to as "Dalian Rongke") is the only company in the world that has the entire industrial chain technology development and production capacity of all-vanadium liquid-flow batteries. In recent years, Dalian Rongke has achieved major breakthroughs in the core fields and key technologies of all-vanadium liquid-flow batteries, and has formed complete independent intellectual property rights in electrolytes, ion conduction membranes, and double electrode plates. The company's energy storage solutions are mainly used in public service facilities, micro-networks, new energy access, and user-side energy storage.

The research and development of all-vanadium liquid-flow battery energy storage system has been the focus of power electrician for many years. At present, the company has applied for a number of patents in the vanadium battery field, and has successively carried out a number of vanadium battery energy storage system demonstration projects in India, Singapore and China.

Battery China Network believes that it seems difficult to determine which battery is the best energy storage technology, because different energy storage technologies adapt to different application scenarios, and various technologies must achieve their maximum value in the most suitable application scenarios. According to different application scenarios, the layout of energy storage technology will also be different. As the energy storage market in China slowly opens, all kinds of energy storage technologies will find their own market position in full market competition.

The page contains the contents of the machine translation.