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Sodium-ion battery industrialization challenges

lithium battery

Previously, a number of organizations predicted that this year will be "sodium battery mass production year", but has been announced sodium-ion battery "car" plan is not many models. Especially since this year, the price of lithium carbonate has fallen, further increasing the market for sodium-ion batteries as a "lithium battery replacement" doubts. Previously sought after by the capital of the sodium-ion battery is still useful?

Sodium-ion batteries are popular for two reasons.

First, the price advantage. Unlike lithium resources, the crust of the earth's sodium resources are abundant and widely distributed, the ocean and salt lakes in huge reserves. The use of sodium-ion batteries basically does not have the problem of resource constraints, and the cost of materials is much lower than lithium-ion batteries. The price of sodium carbonate, the raw material of positive electrode, is always much lower than that of lithium carbonate. Other major elements of the positive electrode, such as iron, manganese and copper, are also cheap commodities. Coal-based materials and collectors used for negative electrodes do not require copper foil, which is lower than those used for lithium batteries.

Second, the performance is complementary. Although sodium-ion batteries have a lower energy density, some of their properties are complementary to lithium-ion battery cells. For example, sodium-ion batteries have a wider temperature range than lithium-ion battery cells. Sodium-ion batteries have the advantages of high internal resistance, small thermal lithium-ion batteries, and low temperature rise during short circuit, so they have an advantage in terms of safety. In addition, sodium-ion batteries have good charging and discharging performance, which can achieve fast power response and is suitable for energy storage applications in power systems.

However, the price advantage of sodium-ion batteries is no longer obvious today. As companies accelerate the layout of lithium mines, the price of domestic battery-grade lithium carbonate began to fall rapidly from the beginning of this year. Although it has gradually recovered since then, it is only 50% of the historical high. The price of lithium carbonate is bound to weaken the market attractiveness of sodium-ion batteries.

At present, the sodium-ion battery energy density and cycle life is only two-thirds and one-half of lithium iron phosphate batteries, it is difficult to meet the demand for power batteries for passenger cars. In terms of cost, despite the huge potential for cost reductions in sodium-ion batteries, but due to the current small overall production, sodium-ion battery production costs are still higher than lithium-ion batteries.

In addition, the pain point of sodium-ion battery industrialization has not been resolved. Although sodium-ion batteries are compatible with the use of lithium-ion battery production equipment, the industry has not yet formed a sound supply chain. First, the sodium-ion battery material system has not yet achieved industry consensus. In cathode materials, for example, the relevant mass production technology for layered oxides has basically been overcome, but Prussian blue crystalline water is difficult to remove, and the relevant preparation technology has yet to be solved, and the relevant mass production technology for polyanion cathodes is also in the development stage. In anode materials, hard carbon has a high specific capacity, but biomass precursors are commonly used with low carbon yield, low cost and small scale. In the electrolyte, the synthesis process of sodium hexafluorophosphate is similar to that of lithium potassium hexafluoride, but the thermal stability is poor. Secondly, the technical standard of sodium-ion battery is imperfect, and the battery voltage platforms under different technical routes are different. In addition, sodium ion compensation technology and life prediction technology have yet to be developed.

In terms of application, it is also necessary to find suitable application scenarios.

Large-scale production is a prerequisite for giving full play to the cost advantages of sodium-ion batteries. At present, lithium-ion battery electric vehicles are poorly promoted in the cold northern regions, and the ability to adapt to low temperatures is strong, so it is expected that sodium-ion batteries will be the first to open the market in northern regions. For the electric two-wheeled vehicle market segmentation, its durability is also better than lead-acid batteries. Because sodium-ion batteries are safer, they are more suitable for use in uninterruptible power supplies such as banks, communication base stations and data centers. Especially in the field of power system energy storage, sodium-ion batteries are expected to become the lowest cost electrochemical energy storage technology, and truly realize large-scale wind power and photovoltaic economic grid.

After years of accumulation, China has a strong R & D and talent base in the field of sodium-ion batteries, the barriers between the laboratory and industrialization are disintegrating, how to find a competitive niche market in the early stage of development, and synchronously achieve a breakthrough in the cost and yield is the key to the development of sodium-ion battery industry at this stage.

What lithium reserves does China have?

Over half of the world's lithium can be refined in China, but the country must import around two thirds of the raw materials. China accounts for 8% of the lithium reserves in the world, which are mostly stored in an igneous rock called podumene, the U.S. Geological Survey reports.