CCTV "Dialogue"丨Liquid flow, lithium battery, sodium battery, which one is the future of energy storage? Is energy storage oversupplied? (Attached with full text)

What are flow batteries, lithium batteries, and sodium batteries? Why do they attract so much attention? What are their advantages over traditional energy storage? Where will they go in the future?

On the evening of August 12, CCTV's "Dialogue" invited professionals and entrepreneurs in the field of electrochemistry, who are:

Chen Jun, academician of the Chinese Academy of Sciences and vice president of Nankai University

Wang Pengcheng, General Manager of Xiamen Haichen Energy Storage Technology Co., Ltd. (Lithium-ion Battery)

Wang Xiaoli, General Manager of Dalian Rongke Energy Storage Technology Development Co., Ltd. (flow battery)

Huang Xuejie, researcher at the Institute of Physics, Chinese Academy of Sciences, and vice president of the China Battery Industry Association (sodium battery)

Du Zhongming, Party Secretary and President of China Electric Power Planning and Design Institute

Let’s see what kind of dance China’s energy storage will perform as it dances on the crest of the wave.

Is new energy storage equal to lithium battery energy storage?

Host: Traditional pumped storage accounts for about 86% of the total energy storage market. Why do people still want to develop new energy storage? Is anyone joining in the fun?

Chen Jun: I don't think it's just joining in the fun. At present, the proportion of pumped storage is indeed relatively high, and the capacity is relatively large. Second, the operating cost is relatively low. But it also has some problems, because pumped storage actually requires two reservoirs, one high and one low, and a conversion between water and electricity, that is, the topography has an impact or the environmental assessment has requirements. In addition, the one-time investment of pumped storage is very large, just like our northwest has good sunshine, but no water, so it is a problem.

Another problem is that water freezes easily in the north in winter, which calls for all-weather energy storage. Electrochemical energy storage is easy to deploy in a distributed manner, has high energy density, and has many other advantages that can reflect the advantages of electrochemical energy storage.

Huang Xuejie: ​​Because electrochemical energy storage has the following characteristics: speed of construction, distributed deployment, can be in a home, in a desert, or on a mountain. Another thing is that the efficiency is also very high, up to more than 90%. And from the perspective of economic efficiency, today it is combined with photovoltaics, and can compete with thermal power in quite a few areas. Of course, I expect that the price of thermal power is unlikely to drop, and the price of photovoltaics plus energy storage will continue to drop. So this advantage will become more and more obvious in the future.

Du Zhongming: The development of energy storage, or the development of new energy storage, is the result of national strategic promotion and a very important service for us to build a new power system. Because our country's long-term power stations are mainly distributed in the central and eastern regions, but our northwestern region has certain conditions for building pumped storage systems, but it is not enough to support the development and construction of such a large number of new energy sources and the needs of system consumption. We need new energy storage to play a large-scale role, and it has many application scenarios, whether on the power supply side, the grid side, or the user side, there are rich application scenarios.

Host: The National Energy Administration also has a figure, saying that by the end of 2022, lithium batteries will account for 94.5% of energy storage. With such a high proportion, does it mean that lithium batteries will dominate the market?

Chen Jun: There are several reasons for this. First, lithium-ion batteries have high energy density. Another reason is that current power batteries are mainly lithium-ion batteries. So from the perspective of the industry, it quickly finds the relevant materials and battery preparation technology. In the future, I personally think that lithium-ion batteries will still account for a large part of the energy storage market.

But at the same time, there are also many electrochemical energy storages, some of which may have many application scenarios, such as aqueous batteries, especially flow batteries and aqueous nickel-iron batteries, because they are inherently safe. In addition, sodium-ion batteries, although their energy density is lower than that of lithium-ion batteries, are still very abundant in terms of resources and should have room for rapid growth.

△Chen Jun, academician of the Chinese Academy of Sciences, vice president of Nankai University

What are the advantages of different types of battery energy storage?

Sodium-ion batteries

Huang Xuejie, researcher at the Institute of Physics, Chinese Academy of Sciences and vice president of the China Battery Industry Association: First, the cost may be low. Replacing all the lithium in lithium batteries with sodium can reduce it by 30%. This 30% is a huge advantage. A price difference of a few percent may determine the life or death of an industry. Second, sodium itself is very abundant. Third, it may be safer.

△Huang Xuejie, researcher at the Institute of Physics, Chinese Academy of Sciences, vice chairman of the China Battery Industry Association

Lithium-ion battery

Wang Pengcheng, General Manager of Xiamen Haichen Energy Storage Technology Co., Ltd.:

First, under the current technical path, lithium battery products are widely recognized for their safety and reliability.

Second, its application is flexible and diverse, including industry and commerce, UPS, data centers, etc., and even the balcony power supplies in Europe have been embedded deeply into household terminals, all of which use lithium batteries.

Third, the advantage is that the industrial chain is relatively mature. Objectively speaking, the lithium battery industry has actually been developed for 30 years.

Fourth, whether it has been internationally recognized is also a challenge. The technical route of lithium batteries, including its environmentally friendly recycling. Especially this year, Europe has raised the issue of carbon footprint. It should be said that the lithium battery technical route is the most likely to be closed-loop.

About the safety of lithium-ion batteries:

First of all, lithium-ion batteries are currently the most commercially available among all new energy storage technologies. In fact, we cannot talk about its safety in general terms. We may need to consider five aspects. The first is the hardware safety of battery manufacturers. The second is the system integration safety of integrators. The third is the safety of safety regulations of owners. The fourth is the data control safety of operators. The fifth is fire safety. Because the most important safety hazard of batteries is actually the consistency issue, that is, the batteries do not work in a uniform manner.

But from the current process route, the frequency synchronization is getting higher and higher. Three years ago, we only heard about megawatt-hour power stations, but this year, 800 megawatt-hour power stations have appeared. In fact, GWh power stations have begun to appear internationally, so its safety is a dynamic process.

△Wang Pengcheng, General Manager of Xiamen Haichen Energy Storage Technology Co., Ltd.

Emerging flow batteries

Wang Xiaoli, General Manager of Dalian Rongke Energy Storage Technology Development Co., Ltd.: First, it is inherently safe. Vanadium batteries are water-based batteries that operate at normal temperature and pressure, without any risk of combustion, explosion or fire.

Second, it has the longest lifespan among current battery technology routes; during the normal development process, the number of cycles must be more than 20,000 times before we will put it on the market.

Third, there is no resource constraint. Its electrolyte exists independently outside the battery and can be recycled throughout its life cycle.

Fourth, to increase the energy storage time, you only need to increase the electrolyte; this is why the main target market of flow batteries now is medium- and long-term energy storage, especially markets such as several hours or even days.

Finally, the capacity is recoverable. The liquid flow battery can achieve this capacity recovery through very simple online chemical means, which ensures the client's benefits.

△ Wang Xiaoli, General Manager of Dalian Rongke Energy Storage Technology Development Co., Ltd.

Chen Jun: I personally think that lithium-ion batteries, for example, should pay more attention to safety in energy storage, especially in large-scale energy storage. The safety of single cells, and the modular safety of the series and parallel connection of single cells, is actually an electrical management and control. In fact, we ordinary people cannot see the battery in energy storage, just like we cannot see the battery in our mobile phones. We only see that this is a large energy storage power station, so the entire electrical control and thermal control are actually the safety of the battery itself.

People will ask, why is the battery technology not used now? This shows that there are still some problems in the operation process. Liquid flow batteries are inherently safe, but they need to solve some difficult problems during long-term operation, especially when operating at low temperatures.

As it happens, today's dialogue actually makes people in the society know that it is good. But there are still some problems for us to solve, and I think it may be better this way.

Huang Xuejie: ​​When we talk about products, we must compare them with more mature products on the market. Compared with lithium iron phosphate, the cost is not low. If we calculate it from the periodic table today, it should be very low. However, semiconductor chips should not be very expensive from the perspective of the periodic table, but the technical requirements are indeed very high. What does this mean? The technology and process of converting raw materials into battery materials must be low-cost and low-carbon. Another thing is that only after the scale is established can the cost be reduced. The second thing is that the life span is not long enough. Today, the battery (life span) reaches more than a thousand times, which can be used to drive a car, and if it reaches 3,000 times, it can be used for home energy storage. But the power system requires more than 10,000 times. We still have a lot of work to do to improve the life span.