By Ren Yunfeng, CIESC
The increasing sales of vehicles using lithium battery have been boosting the development of lithium ion power battery. A relatively complete industrial chain from raw material lithium ore, positive and negative electrode materials, electrolytes, separators, to power battery recycling was formed in China.
Lithium battery enterprises to move closer to lithium ore resources
The upstream of the lithium battery industrial chain consists of raw materials such as lithium ore, cobalt ore, and graphite ore. Leading enterprises include Tianqi Lithium, China Metallurgical Group Corporation (MCC Group), GEM and Ganfeng Lithium.
In China, lithium ore resources are concentrated in western regions, including Tibet, Qinghai and Sichuan, while lithium battery enterprises are located in central and east China. They depend on imports of raw materials. The decentralized distribution of lithium ore resources and lithium battery producers has resulted in underdevelopment of lithium ore. In addition, the supply of lithium battery is mainly dominated by three brine plants, SQM, Albemarle, FMC and one ore producer, Talison. In the future, lithium battery enterprises are looking to move closer to lithium ore resources and are bracing for vast growth potential.
Lithium battery prices have been on an upward path, as demand has been outweighing supply. And the situation is poised to linger in the coming years. Margins of lithium ore will remain large as the advancement of lithium mining technology and the expansion of scale will bring down the costs.
Production of lithium battery feedstock
1. Cathode materials
Lithium iron phosphate, lithium nickel-cobalt manganate, lithium nickel-cobalt aluminate, lithium cobaltate, lithium manganate, etc. are the main cathode materials for lithium batteries. Ternary materials, lithium cobaltate and lithium manganate display relatively high performance. Among them, ternary materials are the most cost-effective. The technology of lithium iron phosphate (LiFePO) is the most mature, but products are currently mainly low-end ones. The property comparison of main cathode materials is shown in Table 1.
Table 1 Comparison of properties of main cathode materials
Properties | LCO | NCM | LMO | LiFePO | NCA |
Voltage platform (V) | 3.7 | 3.6 | 3.8 | 3.3 | 3.7 |
Energy density (Wh/kg) | 150 | 160 | 120 | 150 | 170 |
Tap density (Wh/L) | 2.8-3.0 | 2.0-2.3 | 2.2-2.4 | 1.0-1.4 | 2.0-2.4 |
Advantages | Stable charge and discharge, simple production process | Stable electrochemical performance, good cycle performance | Rich manganese resources, low price and good safety performance | Good safety performance, long service life | High energy density and good low temperature performance |
Disadvantages | Cobalt is expensive and has low cycle performance | Cobalt is expensive | Low energy density and poor electrolyte compatibility | Poor low temperature performance and low discharge voltage | Poor high temperature performance, poor safety, and high technology |
Leading enterprises of cathode materials for lithium batteries in China include Xiamen Tungsten, Pulead Technology Industry, Hunan Ruixiang and Hunan Shanshan, etc.
2. Anode materials
Carbon-based anodes, lithium titanates (LTO), and alloy-based anodes can be used as anode materials for lithium batteries. Among them, LTO has the best performance but is expensive. Graphite anodes are cost-effective. High-end new materials such as mesocarbon microspheres display better performance than other carbon-based materials. Sales of graphite anodes account for 90% of world anodes sales. Table 2 shows the property comparison of main anode materials.
Table 2 Comparison of properties of main anode materials
Anode materials | Subdivision | Specific capacity (mAh/g) | First discharge efficiency (%) | Cycle life (Time) | Safety peformance | Fast charge characteristics |
Carbon-based anodes | Natural graphite | 340-370 | 90 | 1 000 | Moderate | Moderate |
Artificial graphite | 310-360 | 93 | 1 000 | Moderate | Moderate | |
Mesophase carbon microspheres | 300-340 | 94 | 1 000 | Moderate | Moderate | |
Graphene | 400-600 | 30 | 10 | Moderate | Poor | |
LTO | LTO | 165-170 | 99 | 30 000 | Best | Best |
Alloy-based anodes | Silicon | 800 | 60 | 200 | Poor | Poor |
Tin | 800 | 60 | 200 | Poor | Poor |
Leading enterprises of anode materials for lithium batteries include Shanghai Shanshan, Jiangxi Zichen and Shenzhen Sinuo.
3. Electrolyte
Solvents, solutes and additives are mixed to form an electrolytic solution. Their types are generally fixed, with little variability. Solute is the main determinant of electrolyte performance. LiPF6, LiAsF6, LiBF6, LiClO4 and LiCF3SO3 can be used as solute and their electrical conductivity is ranked as: LiAsF6 > LiPF6 > LiClO4 > LiBF6> LiCF3SO3. However, as is highly toxic and causes environment pollution, so LiPF6 has become the mainstream material for electrolyte solutes in lithium batteries.
China's LiPF6 prices have been on the rise after 2016, thanks to the explosive growth in the new energy vehicles, driven by China’s policies to advocate sustainable development of the new energy industry. Electrolyte costs, of which 43% is attributed to LiPF6, has been increasing as a result. Leading electrolyte enterprises include Lishen, Jiangsu Guotai and Shenzhen Capchem Technology Co., Ltd. (CAPCHEM).
4. Diaphragm
Low-end diaphragm materials mainly include polyethylene (PE) and polypropylene (PP). Their production costs have been decreasing in recent years. Wet diaphragm production has been expanding, while demand for dry diaphragm is largely stable. High-end diaphragm materials are subject to high technical barriers.
Domestic diaphragm output has been increasing to meet the growing demand. Leading diaphragm enterprises in China include SENIOR, Jinhui High-Tech and Cangzhou Mingzhu. Leading cells and PACK enterprises include BYD, Lishen Battery and Wanxiang.
Power battery recycling
A large number of power batteries were scrapped after China began to promote the use of electric vehicles in 2009. China’s Ministry of Industry and Information Technology issued the "Interim Measures for the Management of Recycling and Utilization of Power Batteries for New Energy Vehicles" to advocate green manufacturing and protect the ecological environment. The Measures push forward specific requirements for automobile production and power battery recycling.
By 2020 and 2023, the scale of waste power battery recycling market will further expand to RMB13.6 billion and RMB31.1 billion. By 2025, 350 kt of power batteries for electric vehicles in China are predicted to be scrapped annually.
At present, enterprise dedicated to power battery recycling in China include Brunp, GEM, Jintaige, Fangyuan Environmental Protection Company and Jiangmen Chancsun Umicore Industry (JCU). State Grid Corporation of China, China Electric Power Research Institute, BAIC BJEV and PRIDE POWER conduct cascade utilization and commercial energy storage demonstration.
The combination of directional recycling process, social distribution and enterprises’ acquisition is the major mode to meet the recycling demand for waste power batteries.
