Experts explain the future of lithium-ion battery energy storage

The future energy storage hotspot is not coal or iron ore, but lithium. This lightest metal in nature may be the heaviest resource in the future energy landscape. China launched an ambitious electric vehicle plan this year, which will greatly increase the demand for lithium, the main raw material for lithium batteries. When the number of electric vehicles reaches 1 million, China's demand for lithium will exceed the current global lithium supply. Others claim that the automotive industry's shift from oil to lithium is just a switch from one limited resource to another. Under this logic, lithium will obviously replace oil as a symbol of wealth.

Considering the dynamic growth of global lithium mine production capacity and the reduction of lithium use in lithium batteries as technology advances, the above prediction may be too alarmist. However, in China's grand electric vehicle plan, the situation of supply exceeding demand has begun to emerge. There are about 1,000 lithium battery manufacturers participating in the bare-knuckle battle of China's lithium industry, which previews the competition for upstream raw materials in advance. In the upstream of the most promising lithium iron phosphate battery, the supply of lithium iron phosphate is becoming a problem. Tianjin Stellan Company, the world's largest lithium iron phosphate supplier, has a production capacity of only 2,000 tons. There are more than 100 companies in China that are producing lithium iron phosphate at full capacity, but no more than 10 companies can really produce high-quality products. They will be the upstream leaders of the future lithium battery industry. Finding and discovering them will also be the greatest interest of investors.

As early as 1986, when the 863 Program was launched, lithium batteries were considered one of China's strategic industries. However, China's research stagnated for many years, and lithium batteries became a field monopolized by Japan and the United States. It was not until recent years that private enterprises and professional R&D institutions came together, and China's lithium battery technology has made a qualitative leap. In key components of lithium batteries such as diaphragms, China already has a few companies that can compete with the best companies in the world.

The lithium industry is just the tip of the iceberg of the entire energy storage market. Even bigger than the electric vehicle market is the new energy grid connection link and the peak-shaving and valley-filling of urban electricity. These three are an ecosystem that supports each other. Energy storage can not only ensure that the new energy power connected to the upstream power generation link is continuous and stable; at the energy use end, the huge demand difference between day and night also requires energy storage to shave peaks and fill valleys; and for the newly added electric vehicles, some experts said that if all existing vehicles in China are converted to electric vehicles, it will be equivalent to rebuilding a national power grid system, which is simply a catastrophic investment. In the most ideal state, electric vehicles should not only be able to absorb energy, but also transmit electricity back to the power grid to adjust peaks and valleys, which can greatly reduce the excessive construction of the power grid to balance the load. In the ultimate energy map, energy storage will become the cornerstone of a distributed, intelligent and controllable energy pattern. At present, energy storage accounts for less than 2% of the total installed capacity. This obviously means that in the above three aspects, energy storage contains huge business opportunities.

Lithium batteries were once thought to be suitable for the latter two, but in the first phase of the National Wind, Solar, Storage and Transmission Demonstration Project recently invested by the State Grid, the bidding for the 18-megawatt lithium iron phosphate battery energy storage system was suspended. The reason is that its cost is too high, and when the battery in the mobile phone is magnified hundreds of times, the problem of battery consistency has not been solved. In the field of large-scale energy storage, the most popular is the nanosulfur battery, which has an energy density close to that of lithium batteries and does not have consistency problems. Similarly, vanadium batteries, a representative of flow batteries, are gradually recognized as more suitable for large-scale energy storage applications. In the former, the State Grid Corporation is close to industrialization. In the latter, representative companies such as Pu Neng have become one of the most competitive battery companies in the world by acquiring leading foreign technology owners, and have therefore received more than 30 million US dollars in venture capital investment in three rounds.

In fact, there is no perfect product in the battery field. Lead-acid batteries have stable performance but short life and low energy density; sodium-sulfur batteries must ensure an operating temperature of 300°C; vanadium batteries have too low energy density. The most challenging thing for entrepreneurs is to find a market for these batteries that is beneficial and avoids harm. For example, although vanadium batteries have low energy density and large volume, their flow battery structure allows them to be repeatedly and long-term fast charged and discharged. Therefore, they are naturally suitable for large-scale new energy storage that is not sensitive to floor space, rather than peak shaving and valley filling in cities, let alone the narrow space of electric vehicles; for example, lead-acid batteries, which are regarded as backward products, may be first applied to primary electric vehicles in rural markets where there is no problem of charging piles because of their low price. With the cultivation of the market, these pragmatic companies have tickets to upgrade to more advanced products. Therefore, investors may need to be wary of the principle of technology supremacy in this field. Companies that have a keen judgment on product application paths and have innovative business models also have investment value.

So far, we have only discussed the hottest energy storage solutions, but only a small part of them.

Following the principle of energy storage: electricity - other energy - electricity, electricity can be converted into chemical energy, potential energy, kinetic energy, electromagnetic energy and other forms of storage. Among them, physical energy storage includes pumped storage, compressed air storage and flywheel storage; electromagnetic energy storage includes superconducting, supercapacitor and high energy density capacitor storage; electrochemical energy storage includes lead acid, nickel metal hydride, nickel cadmium, lithium ion, sodium sulfur and liquid flow battery storage; phase change energy storage includes ice storage and so on.

With the rapid start of the energy storage market, some traditional energy storage technologies are making a comeback. In early July, Miao Liansheng, chairman of Yingli New Energy, announced in Hainan that Yingli is developing a new generation of flywheel energy storage. Flywheel energy storage converts electricity into high-speed rotating flywheel kinetic energy, and uses the flywheel to drive the generator to generate electricity when needed. It was used for power storage experiments in Japan and the United States in the 1990s, but there has been no large-scale energy storage application to date. The flywheel has regained attention thanks to the breakthrough in magnetic levitation using high-temperature superconductors. This makes magnetic levitation bearings possible, which can eliminate bearing friction losses; secondly, the emergence of high-strength materials such as carbon fiber can make the flywheel have a higher speed, allowing the flywheel to store more energy.

The application prospect of phase change energy storage - building energy conservation is more imaginative. China's building energy consumption accounts for more than 30% of the total energy consumption. Although phase change energy storage such as ice storage cannot store electricity, it can regulate heat. Combined with passive energy-saving technology, it can solve the problem of building energy conservation on a large scale and inexpensively. For China, this is a more cost-effective energy-saving and emission-reduction path than electric vehicles. In places such as Shanghai that have restrained and rational planning for a low-carbon economy, building energy conservation is gaining policy support from the government. In the field of public and commercial buildings that are easy to promote, phase change energy storage obviously has a lot of opportunities.