The nickel compound obtained from mining is six production steps away from the precursor materials for cathodes in lithium-ion battery cells, which are key for cost and performance. If you want to participate in the smart energy future of storage, you have to invest heavily, like Tsingshan Group is doing.
Tsingshan Group has abundant laterite nickel ore resources in Sulawesi, Indonesia, which can be used not only for direct smelting and purification to produce nickel-containing steel, but also for refining high-purity nickel. With nickel quickly becoming the most heavily relied- upon cathode material for lithium nickel manganese cobalt oxide (NMC) batteries, the steel conglomerate is charging ahead with mass investment.
Laterite nickel ore is primarily distributed within 30° of the north-south dimension of the equator, and is concentrated in Indonesia, Australia, and Brazil. The world’s largest steel manufacturer, Tsingshan Group, is now taking advantage of these resources to expand its business in the new energy industry.
The company started its journey to nickel production to support its stainless steel business, but the international conglomerate is now using its resources to expand into battery storage, which is a more complex process that requires more than $700 million worth of investment. Unlike the high purity content used for NMC batteries, nickel for stainless steel only needs to be made of nickel-containing pig iron, without the need to separate the nickel element. To produce the battery precursor material, the separation process starts with the wet intermediate from stainless steel production, and then goes into further purification and refining to obtain nickel salt or pure nickel. The refined nickel then is sent to Qingmei Energy Materials, a joint venture of Tsingshan and GEM, to develop high-quality precursor for lithium-ion battery cells utilizing some of the world’s most advanced production lines.
Currently, the primary lithium battery cell cathode materials that are being commercialized are lithium cobalt oxide (LCO), lithium ion manganese oxide (LMO), lithium iron phosphate (LFP), and nickel manganese cobalt oxide (NMC). Among them, lithium NMC batteries are relatively balanced in terms of both capacity and safety, while also providing excellent comprehensive performance.
Qingmei Energy Materials has attracted support from the five largest battery companies, including Samsung SDI, CATL, LG Chem, Panasonic, and BYD. It is also backed by more than 200 other related supporting enterprises, financial firms, and investment institutes. Hou Min, the vice president of Ruipu Energy – another Tsingshan subsidiary that is focused on storage and the clean energy transition – manufactures batteries with different chemistries. Min recently sat down with pv magazine for an in-depth discussion about the growing number of joint venture projects that are advancing NMC battery technology, and the complexities associated with different chemistries.
The technical challenges associated with producing the NMC precursor are much greater than those related to the production of stainless steel, which has been the nuclei of Tsingshan’s traditional business model.
“The production process includes six major areas: production preparation, batching, wet reaction, material cleaning, material drying, and product testing,” Min said. “Each section has many quality-control points. The nitrogen concentration, temperature, PH value, drying time, and temperature during the process will have an effect on the impurity content, component content, and tap density of the product. The purity of nickel in the precursor is very high – it usually needs to be above 99.9% to avoid impurity elements, particularly iron, which will affect battery performance.”
“High energy density and good cycling performance are the biggest advantages of NMC lithium batteries,” says Min. Voltage is an important indicator of battery energy density, which determines the efficiency and cost of the battery. The higher the operating voltage, the larger the specified capacity. For batteries of the same volume, weight, and even the same ampere-hour, the lithium NMC lithium battery wins out the others due to its higher voltage platform and longer battery life.
In the NMC compound, “Ni,” nickel, is the most active element to increase energy density, but too much will cause instability of the battery. “Co,” cobalt, the most expensive element in the cathode combination, improves stability and extends battery life. Cobalt also determines the charge and discharge speed, and efficiency of the battery. And “Mn”, manganese, can lower internal resistance to increase the safety and stability of battery.
“Normally, lithium-ion batteries use graphite or the like as a negative electrode, or anode, a non-aqueous solution as an electrolyte, and a lithium alloy material as a positive electrode, or cathode,” says Min. “Since the positive electrode material occupies a large proportion (with mass ratios of positive and negative 3:1 – 4:1), the performance of the positive electrode material directly affects the performance of the lithium-ion battery, and its cost directly determines the cost of the battery too.”
Cost benefits shifting cathode combinations
Through different ratios of the combined three elements (Ni-Mn-Co) in the lithium NMC battery, a variety of cathode materials are derived. They are generally divided into two categories: Ni-Mn isometric and high nickel. The Ni-Mn isometric batteries come in two cathode combinations: 1-1-1 and 4-2-4. The cathode combination of 1-1-1 is one-third nickel, one-third manganese, and one-third cobalt. Due to the high costs of cobalt, battery manufacturers are steering toward nickel-based systems, such as 5-3-2, and 8-1-1 combinations. With lower costs, higher energy density, and longer life cycles than cobalt-based cells, high nickel is considered to be the most promising cathode material for the next generation of lithium-ion batteries.
In recent years, research and commercialization of nickel-based lithium batteries have made great progress in China, Japan, and South Korea. The development and use of NMC battery materials has gradually transferred from 1-1-1 to 5-2-3, and now even 8-1-1 batteries are being applied to some electric vehicles today. From the perspective of both production costs and energy density, the application of high nickel materials for Lithium-ion battery technology appears unstoppable.
“I do believe that NMC battery is the trend, and 8-1-1 will become more and more popular in the coming future,” Hou stressed with confidence. “This makes nickel the core element of lithium batteries, as we are using much more nickel in 8-1-1 than older cathode combinations such as 5-3-2.”