New energy perspective| Academician Ouyang Minggao analyzed the technology roadmap for the sustainable development of power batteries

Edited by | Wang Yifen

Produced by | Commercial vehicle network (shangyongqiche)

Previously, Ouyang Minggao, an academician of the Chinese Academy of Sciences, gave his views on hot spots such as vehicle technology, battery sustainable development, charging and replacing and electric vehicle smart energy, and hydrogen energy and fuel cells with the title of "Promoting the Sustainable Growth of New Energy Vehicles". This article is based on Ouyang Minggao's speech, focusing on the power battery sustainable development technology roadmap and related analysis.

Academician of the Chinese Academy of Sciences Ouyang Minggao

Power battery installed capacity

The installed capacity of power batteries in the mainland has increased with the rapid growth of electric vehicles. A total of 092 million kWh of vehicles will be loaded from January to September 2021, and it is expected to be around 150 million kWh for the whole year. It is expected to be around 600 million kWh in 2025 and between 1.5 billion kWh and 2 billion kWh in 2030. Based on the aggressive forecast of the annual sales of 55 million electric vehicles in the world in 2030, the annual loading volume of power batteries given by foreign institutions is 5 billion kWh, while the conservative forecast is 3 billion kWh.

Based on the ownership of electric vehicles, it is possible to predict the total ownership of on-board batteries in China, which is expected to exceed 2 billion kWh in 2025, more than 7 billion kWh in 2030, and more than 15 billion kWh in 2035.

Due to the hot electric vehicle market, the upstream battery industry is stimulated to expand rapidly. According to statistics, China's power battery planning capacity will reach 1 billion kWh in 2023, and close to 2.5 billion kWh in 2025. Of course, the planned production capacity will be greater than the annual output of power batteries, and at the same time, in addition to the annual output of automotive batteries, there are a series of other uses such as energy storage batteries, and it is estimated that the total shipment of batteries in 2025 will be about 1 billion kWh.

Rapid expansion of battery production stimulates periodic price increases in upstream materials. At the same time, it will also cause public concerns about the shortage of material resources. From the perspective of potential, the global lithium resources economic recoverable reserves of 21 million tons, if calculated according to the ternary 811 battery material system, can produce batteries 200 billion kWh. On an average of 100 kWh per vehicle, 2 billion electric vehicles can be manufactured. Of course, this can't all be used in cars, but elsewhere. But this is an economically recoverable reserve, with a total exploration reserve of 86 million tonnes. And because the total exploration reserves have been increasing in recent years, it seems that the problem is not very big.

However, the resources of cobalt are less optimistic, with only 7.1 million tons of economically exploitable reserves. According to this calculation, it can only reach 95 billion kWh. As for the resources of manganese, there is no problem and it is very surplus.

However, the distribution of resources is uneven, and 3/4 of lithium mines are distributed in Australia, Chile and Argentina. Two-thirds of the cobalt mines depend on the Democratic Republic of the Congo in Africa. Half of the nickel mines depend on Indonesia and Russia. The distribution of resources is extremely uneven. Therefore, the pressure of resources is still there, and it cannot be taken lightly.

The cycle of battery material is sustainable

If recycling is done well, the problem of supporting development will not be very large. The material cycle consumes energy and emits, battery production will also consume energy and emissions, and sustainable development is also a major issue, that is, the carbon emissions of the whole life cycle of the battery are problems. In the case of ternary high-nickel 811 lithium-ion batteries, the carbon emissions per kWh of the whole life cycle are about 87 kg. The main reason why the relative carbon emissions of ternary batteries are relatively high is the cathode material, including the carbon emissions prepared by the precursor and cathode materials account for half of the total emissions. The life cycle carbon emissions of lithium iron phosphate batteries are reduced by about one-third compared with the ternary NCM811 chemical system. As for sodium-ion batteries, carbon emissions are even lower.

How to solve the problem of carbon emissions? First, the clean power, the battery industry chain should be transferred to the west as much as possible, Sichuan, Guizhou, Yunnan, Qinghai is a very suitable place, the use of renewable energy and local resource advantages is a fundamental way. Second, battery recycling and recycling. Third, the production process of the whole industry chain should be improved and the energy efficiency of key links should be improved.

From the perspective of recycling, the total number of batteries that need to be recycled and cascaded in China will reach 125 million kWh in 2025. The national level attaches great importance to battery recycling, the State Council, the Development and Reform Commission, the Ministry of Industry and Information Technology, issued a lot of documents, and now meet the conditions of the waste power battery comprehensive utilization industry specifications there are 14 recycling enterprises, the future will continue to expand.

There are now three main means of recycling: dry, wet and physical. The dry method is burning, the energy consumption is large, and there are still environmental protection problems. Wet method is a little less productive, the equipment is more complex, and there are some corrosive solvents. What is now being celebrated is technological innovation for physical recycling, battery repair and material recycling. The decommissioned batteries of electric vehicles should be sorted through accurate battery remaining power tests. It is then divided into categories for restoration, cascade utilization and material recycling.

From the perspective of the potential of battery life cycle emission reduction, under the existing power structure, physical recovery emission reduction is more than 50%,32% by wet recovery and 3.5% by fire recovery. With the increase of the proportion of green electricity, carbon emissions will be reduced by 12% in the context of power structure in 2030; carbon emissions will be reduced by 75% under the background of deep decarbonization of the power grid in 2050; and 100% green electricity can achieve nearly zero emissions in the whole life cycle of battery production and manufacturing.

Other batteries to replace the current lithium batteries?

This is a sustainable development issue of power battery technology. First of all, lithium-ion batteries will be used for a long time. The specific energy limit of the current generation of lithium-ion batteries is about 300 watt-hours per kilogram, and the new lithium-ion batteries can reach 350 watt-hours to 400 watt-hours per kilogram. In 2025, there will be a first-generation all-solid-state battery with a relative energy ratio of existing liquid electrolyte lithium-ion batteries. After 2030, there will be a second generation of all-solid-state batteries using new positive and negative electrode materials, and the specific energy will be increased to 500 watt-hours per kilogram, and there will also be high-specific energy lithium-sulfur batteries and metal-air batteries.

Sodium-ion batteries have now emerged, but all aspects of performance can not meet the requirements of high-performance vehicles. It is expected that by 2035, the performance of sodium-ion batteries and potassium-ion batteries will be greatly improved, and the specific energy will reach about 300 watt-hours per kilogram. Comparable to today's high-specific energy lithium-ion batteries.

From the perspective of sustainable development of the battery industry, it is estimated that existing lithium-ion batteries, including solid-liquid hybrid lithium-ion batteries, will still be absolutely dominant until 2030. The first generation of all-solid-state battery industrialization, accounting for nearly 1% of the market, the time point may be around 2030. After 2035, a new generation of solid-state batteries, potassium, magnesium, sodium, lithium-sulfur and other types of batteries will enter the market. By 2050, liquid lithium-ion batteries are likely to be reduced to about 20%.

The trend of intelligent battery whole chain

Materials need to be recycled, but also to develop new material systems and to tap the performance potential of existing materials. Each battery material has a theoretical value than capacity, but in fact, it is difficult to achieve this theoretical value in battery products. This is because today's material synthesis and battery design mainly use the "trial and error method".

Through intelligent means, the design can be further optimized, such as the material genome based on artificial intelligence material screening and design, can use simulation design, reuse intelligent manufacturing, intelligent battery management in the application process, and finally intelligent recycling after reaching the service life, to achieve the whole process of intelligence. This is also the core idea of the EU's 2030 battery plan.

Through intelligent design, the gap between the actual performance of the battery and the theoretical value is reduced by half, intelligent recycling finally makes the utilization rate of recovered raw materials close to 100%, the carbon footprint of the whole life cycle is reduced by 1/2, the potential of science and technology is very large, and the sustainable development of power batteries is guaranteed.