Power battery 'sodium' can work？

On the road to reducing costs and increasing efficiency of power batteries, sodium-ion batteries, the rising star, have recently become a hot topic.

On February 23rd, the industry's first sodium-ion battery test vehicle, jointly developed by Shenzhen max power company, was unveiled. On the same day, employees of Duflon, a listed company, also stated that the company had sodium-ion battery products undergoing vehicle testing. In addition, companies such as CATL, Guoxuan High-Tech, EVE Energy, and Funeng Technology are accelerating the research and development of sodium-ion batteries.

Many battery companies are flocking to the sodium-ion battery new track, and one of the reasons is its cost advantage. Academician Chen Liquan of the Chinese Academy of Engineering stated at the Sodium-ion Battery Industry Chain and Standard Development Forum held at the end of last year that the cost of sodium-ion batteries is expected to be more than 20% lower than that of lithium iron phosphate batteries. However, he also added the prerequisite conditions, including the improvement of the industry chain, the maturity of technology, and economies of scale.

If one of the main purposes of developing sodium-ion batteries in the past two years was to reduce material costs, does sodium-ion batteries still have a price advantage in the current situation of continued lithium price decline? The answer is yes. Although lithium prices are currently declining, they are still at a high level. On March 1st, the price of battery-grade lithium carbonate dropped to 387,500 yuan per ton, breaking through 400,000 yuan per ton and a 34% decrease from the fourth quarter of 2022's peak of 600,000 yuan, but still about 9 times higher than the approximately 42,000 yuan per ton before the COVID-19 pandemic in the fourth quarter of 2019. Moreover, due to limited lithium reserves, long development cycles, and multiple links in the industry chain, coupled with transportation disruptions caused by global instability and the rapid growth of global new energy vehicle production and sales leading to a sharp increase in demand, lithium prices are unlikely to return to the low levels of 2019. Reports from several international market research institutions have stated that lithium prices will remain around 400,000 yuan per ton this year, and unless there are unexpected circumstances, they will hover between 250,000 and 300,000 yuan per ton by 2025. In addition, lithium and cobalt, which are required for ternary lithium batteries, are rare metals, so there is limited room for price reduction in lithium-ion batteries. In contrast, sodium-ion batteries require sodium salt as a raw material, which is abundant and inexpensive, and the use of aluminum foil as a current collector for the negative electrode can further reduce costs by about 8% and reduce weight by about 10%. Therefore, unless there is a significant overall technological innovation in lithium-ion batteries, and as long as the price of lithium carbonate remains above 150,000 yuan per ton by 2026, sodium-ion batteries will still have a cost advantage.

In addition, sodium-ion batteries have the advantages of non-overdischarge characteristics, allowing the battery to discharge to 0 volts, good thermal stability, good low-temperature performance, high safety, and fast charging capability. It is reported that Chonghong New Energy Materials Laboratory has achieved the innovation of 70% charge in 26 seconds for sodium-ion batteries, although it still has some distance to go for industrialization, it has demonstrated the excellent performance of sodium-ion batteries.

Amid the layout of numerous companies, sodium-ion batteries are poised for development. However, like any new technology, sodium-ion batteries have their strengths and weaknesses. To achieve industrial application and establish a presence in the market, further breakthroughs are needed. From a technical perspective, sodium-ion batteries still need to address issues such as low energy density and short cycle life. For example, the energy density of the square-shaped battery cells provided by Zhongkehai Sodium for Sihao New Energy is 155Wh/kg, whereas conventional lithium iron phosphate batteries have an energy density of around 200Wh/kg, and ternary lithium batteries have an energy density of around 240Wh/kg. In other words, for batteries of the same weight, the driving range of sodium-ion batteries is only about 67% of ternary lithium batteries and 80% of lithium iron phosphate batteries. The experimental vehicle by Sihao New Energy in this case is a small electric car with a driving range of 252 kilometers. Sodium-ion batteries are still "insufficient" for larger electric vehicles with longer driving ranges.

In terms of cycle life, lithium iron phosphate batteries typically have an average cycle life of 6,000 cycles, while ternary lithium batteries have an average cycle life of 3,000 cycles. In contrast, the average cycle life of sodium-ion batteries is only 1,500 cycles. Based on the characteristics of sodium-ion batteries, many industry insiders believe that sodium-ion batteries will become the battery of choice for the next generation of small and micro electric vehicles and energy storage. To tap into a broader market, sodium-ion batteries still need to make efforts in technical research and development.

Currently, some battery companies have stated that they can increase the energy density of sodium-ion batteries to a level comparable to lithium iron phosphate batteries this year. They aim to improve the cycle life of sodium-ion batteries through internal structure design, material selection, and voltage changes. It is said that the first-generation sodium-ion batteries by CATL (Contemporary Amperex Technology Co. Ltd.) can achieve 3,000 charge-discharge cycles, and this number is expected to increase with technological advancements. CATL's next-generation sodium-ion batteries will surpass an energy density of 200Wh/kg. Once the shortcomings of sodium-ion batteries are addressed, their prospects will be even brighter.

Currently, sodium-ion batteries are still in the early stages of promotion. For power battery companies, in order for sodium-ion batteries to be accepted by the market, they need to overcome technological bottlenecks, fill in technological gaps, and have realistic profit plans. For example, some companies envision combining sodium-ion batteries with lithium-ion batteries in a certain proportion, integrating them into the same battery system, and achieving high cost-effectiveness through precise algorithms in the battery management system (BMS) for balanced control of different battery systems. This approach can optimize the battery system and demonstrates a good strategy for integrated development.

Some industry insiders believe that 2023 could be the "year of industrialization" for sodium-ion batteries, with global sodium-ion battery shipments expected to exceed 90GWh by 2025. Nowadays, more and more battery companies are entering this new track, which will undoubtedly accelerate the development and commercialization of sodium-ion battery technology.

The global new energy vehicle industry is accelerating its development, with various new energy vehicle models emerging, and the technology roadmap for power batteries is becoming more diverse. With the development of the industry, technological advancements, and diversified market demand, lithium-ion batteries, sodium-ion batteries, solid-state batteries, hydrogen fuel cells, and other power batteries will coexist in the long term. They will complement each other in terms of strengths and weaknesses in technology and fulfill market demand.