In 2017, the competition between lithium iron phosphate and ternary lithium batteries was in full swing in the lithium battery industry. The market share of lithium iron phosphate in passenger vehicles was gradually decreasing, and even BYD announced that all its passenger vehicles would use ternary lithium batteries next year.
However, lithium iron phosphate batteries still have great potential in the commercial vehicle market. By the end of this year, BYD's total power battery production capacity will reach 16 GWh, of which 10 GWh will be lithium iron phosphate batteries and 6 GWh will be ternary lithium batteries.
The biggest obstacles to the development of new energy vehicles lie in driving range and charging time, making improving energy density and fast charging the two major goals of battery companies. In the rumored 2018 subsidy policy adjustments, energy density, driving range, and even Ekg will be redefined, but the changes to fast charging will be minimal compared to 2017.
With lithium iron phosphate batteries losing ground in the passenger vehicle market, can they retain their position in the commercial vehicle sector by relying on fast charging, low cost, and high safety?
1. Advances in Lithium Iron Phosphate Fast Charging Technology
In the adjustment of the new energy vehicle subsidy scheme at the end of 2016, the three levels of fast charging rate, namely "3C-5C", "5C-15C", and "15C+", could receive subsidies of 0.8 times, 1 times, and 1.4 times respectively, which stimulated lithium battery companies to accelerate the research and development of fast charging.
Traditional lithium iron phosphate batteries have poor conductivity, which can cause them to overheat during fast charging and affect battery life. Therefore, by improving the conductivity of the materials, perfecting the battery thermal management system, and making up for the shortcomings through technological innovation, lithium iron phosphate has great potential in fast charging.
CATL has developed "super electron mesh" technology for the positive electrode, enhancing the electronic conductivity of lithium iron phosphate by up to 1000 times that of ternary materials. For the negative electrode graphite surface, "fast ion ring" technology is used for modification. The modified graphite combines super-fast charging and high energy density characteristics, eliminating byproducts during fast charging. It features 4C-5C fast charging capability, achieving 10-15 minute fast charging while maintaining a system-level energy density of over 70Wh/kg and a cycle life of 10,000 cycles. In terms of thermal management, CATL utilizes its self-developed thermal management system, which fully identifies the "healthy charging range" of the fixed chemical system under different temperatures and SOCs, enabling "all-weather" fast charging.
Wotech: In terms of cathode materials, Wotech uses lithium iron phosphate with a smaller particle size of 100nm~300nm, while the common lithium iron phosphate particle size on the market is between 300~600nm. This allows lithium ions to have a faster migration speed, enabling higher charge and discharge rates. For anode materials, Wotech also uses smaller-particle-size artificial graphite for carbon coating: the smaller particle size facilitates lithium ion desorption and insertion; carbon coating optimizes and improves battery cycle life; and the microporous carbon structure facilitates electrolyte adsorption and retention, thus improving cycle life.
2. Commercial Operations' Demand for Fast Charging
Limited by the theoretical limit of energy density, lithium iron phosphate has limited room for future development in this area. However, for commercial vehicles such as buses, logistics vehicles, and special-purpose vehicles, increasing energy density is not essential; improving operational efficiency and saving operating costs are the top priorities.
In addressing the range anxiety issue of new energy vehicles, battery swapping, increased battery capacity, and fast charging have become the three main approaches. From a comprehensive operating cost perspective, fast charging is particularly suitable for buses, school buses, and other vehicles operating on fixed routes. It eliminates the need to excessively push the battery's energy density; simply charging during breaks in operation is sufficient for 24/7 operation.
For the emerging new energy logistics vehicle market, the test of operation is particularly important. Increasing costs by adopting high-energy-density batteries for the sake of transportation capacity or increasing battery load is not worthwhile. Using fast charging to balance operating costs is the best choice before there is a revolutionary breakthrough in lithium battery technology.
In the fast charging market, lithium titanate and lithium manganese oxide each hold a certain market share, while lithium iron phosphate fast charging has also made remarkable progress this year, achieving rapid development. However, judging from the models included in this year's catalog, none of them have a fast charging rate exceeding 15C, indicating that there is still significant room for improvement in charging rate.
3. The life-or-death ordeal of 2020
Since ternary lithium batteries were removed from the list of vehicles exempt from purchase tax in 2016, lithium iron phosphate batteries have dominated the bus market. However, with the withdrawal of subsidies in 2020, the entire market will be reshuffled. Cost and efficiency will be the core considerations in the market. For the commercial sector, there will be more considerations regarding comprehensive operation, and fast charging is a more pressing need than energy density.
Looking at the production capacity ratio of lithium iron phosphate and ternary lithium batteries of CATL and BYD, it is currently around 2:1. Lithium iron phosphate still dominates, but is mainly concentrated in the commercial vehicle market. In the future, with the rapid growth of passenger vehicles, it will gradually approach 1:1. The advantage of lithium iron phosphate in the commercial field will continue for a long time, and with the support of fast charging, it will not be difficult to maintain its position.
The battle between lithium iron phosphate and ternary lithium batteries is far from over. Most battery companies, including BYD and CATL, are pursuing a diversified development strategy while innovating in technology. CATL's high-rate fast-charging batteries will also be launched next year.
The future of the lithium battery industry will still be driven by technology. However, for car manufacturers and operators, the type of battery technology used is not important; only the most suitable technology is the best.
