In the next decades, electric vehicles will be developed in a large scale. According to IEA forecast, the global electric vehicle ownership will rise from 3.7 million in 2017 to 130million by 2030, and the annual sales volume will reach 21.5 million. In this scenario, the annual capacity of new batteries will rise from 68 GWH in 2017 to 775 GW in 2030, 84 per cent of which will be used for light vehicles. China, EU, India and the United States accounted for 50%, 18%, 12% and 7% respectively.
In the past 20 years, with the expansion of production scale, the lithium-ion technology leading the battery of electric vehicles has greatly increased and the price has decreased greatly, which has made the price performance of electric vehicles begin to compete with fuel vehicles.
Key drivers
Since its inception in 1990, lithium-ion batteries have been widely used in consumer electronics, energy storage (household, public utilities), and electric vehicles. With the expansion of production scale, its performance has been greatly improved and the price has declined greatly.
In the future, the four key factors driving the cost reduction and performance improvement of lithium-ion batteries are: chemical materials, battery capacity, processing scale and charging speed.
chemical materials. Cathode materials include lithium nickel manganese cobalt (NMC), lithium nickel cobalt aluminum oxide (NCA), LiMnO2 (LMO) and lithium iron phosphate (LFP); Most anode materials are graphite, and lithium titanate (LTO) will be used in heavy vehicles for new cycle life. The important advantage of NMC and NCA technology is higher energy density, which leads the light battery market; LFP has low energy density, but it has become an important chemical substance used in heavy electric vehicles (i.e. buses) due to its higher cycle life and safety performance. Chemical materials have a great influence on the cost of batteries. The price gap of batteries with different chemical materials can reach 20%.
Battery capacity and size. The battery capacity of electric vehicles is very different, and the battery capacity of the three small electric vehicles which are the best-selling in China is 18.3-23 kilowatt hours; The battery capacity of medium-sized vehicles in Europe and North America is 23-60 kwh; The battery capacity of large vehicles is between 75 and 100 kilowatt hours. The larger the battery capacity, the lower the cost. It is estimated that a 70 kilowatt hour battery has a 25 per cent lower unit energy cost than a 30 kilowatt hour battery.
Processing scale. Another important factor is to make the scale of Zhang Da process to realize the scale economy. At present, the typical plant production range is about 0.5-8 GWH / year, and the output of most plants is about 3 GWH / year. According to the typical capacity of 20-75kwh of a single electric vehicle, the output of a single plant is equivalent to the capacity of 6000-400000 battery packs per year. At present, Germany, the United States, China, India and other places are building a batch of more production battery plants, including Tesla's super plant with annual output of 35 GW.
Charging speed. The current technology can charge 80% in 40-60 minutes. This demand adds the complexity of battery design, such as reducing the thickness of electrodes, which will increase the cost of batteries; The energy density of the battery is reduced, and the life of the battery is shortened. A U.S. Department of energy decomposition statement that changing the battery design to accommodate 400 kilowatt charging would double the cost of the battery.
Material revolution leads the future trend
According to the IEA decomposition, lithium-ion batteries will still dominate in the next 20 years, but their chemical materials will gradually change.
Around 2025, a new generation of lithium-ion batteries with low cobalt, high energy density and cathode characteristics such as lithium nickel manganese cobalt (NMC) 811 will enter mass production. Adding a small amount of silicon into the graphite anode can increase the energy density by 50%, and the electrolyte salt which can withstand high voltage will also help improve the performance.
From 2025 to 2030, lithium-ion batteries with lithium metal as cathode and graphite / silicon composite as anode may enter the design stage, and even solid electrolyte can be introduced to further improve energy density and battery safety. In addition, lithium ion technology may be replaced by other batteries with higher energy density and lower theoretical cost, such as lithium air, lithium sulfur, etc. However, the development level of these technologies is still very low, and the actual performance is still to be detected.
In the nature main issue, published on July 26, 2018, an article entitled "ten years from the lithium electronic battery revolution" pointed out that the evolution speed of performance and price of lithium-ion batteries is slowing down. The main reasons for the above problems include: in the crystal structure of electrode materials, the amount of charge that can be stored is close to the theoretical maximum; The rise of market scale is difficult to bring about a large price reduction. Worse, electrode materials such as cobalt and nickel are very scarce and expensive, and demand for cobalt and nickel is expected to exceed production in 2030-2037 (or earlier) without any new changes. On the other hand, new alternative electrode materials, such as abundant iron and copper, are still in the early stage of research. This paper calls on material scientists, engineers and funding agencies to increase the research on electrode materials based on abundant iron and copper, otherwise, the large-scale development of electric vehicles will be limited.
Economic balance
The important factors affecting the cost of electric vehicles and fuel vehicles include: battery price, body size (affecting fuel economy and battery size of electric vehicles), fuel price and annual mileage.
In terms of battery price, for batteries with a production scale of 7.5-35 GWH / A and battery capacity of 70-80 kwh, the cost of the battery can be reduced to $100-122 / kWh by 2030, which is very close to the cost reduction target of EU (US $93 / kWh), China (US $116 / kWh) and Japan (US $92 / kWh).
The cost gap between electric vehicles and fuel vehicles will decrease with the increase of mileage, but the impact of battery price and gasoline price on the gap is more than the size of the vehicle body. For example, when the battery price is $400 / kWh, electric vehicles are very competitive and fuel vehicles will be a more economical option.
If the price of electric vehicle battery is lower, the price of gasoline is higher, and the daily mileage is higher, it is more economical to choose small electric vehicle or plug-in hybrid vehicle than small fuel vehicle. For example, if the battery price is $120 / kWh and the gasoline price is higher than today's level, pure electric vehicles will be a more economical option regardless of the length of mileage. If the battery price is equal to $260 / kWh, the more economical option is to drive more than 35000 km / A and the oil price reaches $1.5 / L.
For large electric buses, if the battery price is lower than $260 / kWh, the electric buses driving 40000-50000 km / year have cost competitiveness in areas with high diesel tax system.
The goal of the lithium battery industry is to develop batteries with stronger function, larger capacity, longer service life, shorter charging time, and lighter weight. Lithium-ion batteries are usually composed of a negative electrode (anode), a positive electrode (cathode), and a separator. Lithium compounds used in lithium batteries have specific particle size distribution requirements. The use of ultra-fine lithium powder can improve battery performance, including higher available capacity, longer service life, faster-charging rate, higher efficiency, consistent discharge rate, and reduced size and weight.
In addition to the mechanical and thermal resistance of the separator, the key factors affecting the quality and safety of the battery include chemical composition, shape and particle size distribution of the active material, and homogeneity. Through continuous research and development, ALPA has a complete set of lithium battery anode and cathode material treatment scheme and equipment, which can meet the complex process requirements, including dust-free feeding, magnetic separation, ultra-fine grinding, grading, powder conveying, metering and packaging, automatic batching, intelligent control and other powder process integrated design.
