Will sodium ion batteries overturn lithium batteries? Comparative analysis of sodium batteries and lithium batteries

Will sodium ion batteries overturn lithium batteries? Comparative analysis of sodium batteries and lithium batteries

Some friends also asked me, and others told me that sodium ion batteries will overturn lithium batteries in the future. If that's the case, will lithium mines lose value?

This is indeed one of the ultimate issues in investing in the lithium battery industry, and I have been paying attention to sodium ion batteries for a long time. I have also thought about this issue for a long time. Below, I will share my personal opinion on this issue.

1、 Principle and performance of sodium ion batteries

Firstly, sodium ion batteries and lithium batteries are similar in principle, that is, they charge and discharge by utilizing the back and forth migration of Na+between the positive and negative electrodes. During charging, Na+is released from the positive electrode and inserted into the negative electrode through the electrolyte membrane, causing the positive electrode to be in a high potential sodium poor state and the negative electrode to be in a low potential sodium rich state. The discharge process is the opposite.

Let's take a look at the specific differences (as shown in the figure below). The sodium ion mass is relatively large, and the insertion and removal processes are more difficult during charging and discharging, resulting in a higher internal resistance of the battery; The upper limit of energy density for lithium batteries is 170-180WH/KG, while the upper limit for sodium batteries is 150WH/KG.

Currently, most sodium batteries in the market have an energy density of around 125WH/KG. Some sodium battery companies also claim to be able to reach 145WH/KG, but to reach this near limit level, would the cost be higher? The current energy density of lithium iron phosphate batteries is close to the limit of 170WH/KG, so there is a gap in energy density.

Overall, lithium batteries have advantages in energy density, fast charging, and cycle life, which is why the mainstream choice in the market is lithium batteries. This is because the fundamental physical differences lead to different battery characteristics, which cannot be changed. That is to say, various improvements can be made to bring the battery to its limit, but it will not exceed the limit.

Sodium ion batteries are not always inferior to lithium batteries in terms of performance. In terms of low-temperature performance, lithium batteries are prone to lithium precipitation when charged at low temperatures, while sodium ions do not precipitate. The capacity retention rate of sodium ion batteries at minus 20 ℃ is still above 88%.

Lithium iron phosphate batteries are also constantly improving. In the past two years, manganese iron phosphate batteries have an energy density density 15-20% higher than conventional lithium iron phosphate batteries, and their low-temperature performance has also been improved. The battery capacity retention rate is 85% at zero 20 ℃. It seems that the improved version of lithium iron phosphate manganese iron lithium phosphate battery is superior to sodium battery in most aspects of performance.

The improved version of lithium iron phosphate manganese iron lithium battery will also be 10-15% more expensive, and sodium batteries are not focused on performance, but on cost-effectiveness. Cheap price is the core competitiveness of sodium batteries.

2、 Cost analysis of sodium batteries

In terms of performance, many batteries have better performance than lithium batteries. Why has lithium batteries become mainstream? Because in terms of comprehensive cost-effectiveness, lithium batteries are the best. This is the most rational choice and also the market's choice.

This round of soaring lithium prices has led to the price of lithium carbonate, the core raw material of lithium batteries, rising from 50000 to 500000 yuan. Lithium resources are still relatively scarce globally, but sodium is not scarce and can be found everywhere. Therefore, when the price of lithium carbonate rises and the price of lithium batteries also rises, sodium batteries reappear in the view of industry players. By replacing lithium with cheap sodium, sodium batteries produced may have poor performance, but they are cheaper, Overall, it has a higher cost performance ratio. This is the original intention behind the re emphasis on sodium batteries.

It should be noted that sodium batteries are not a technology that has only emerged in recent years, nor are they a new invention. They have only been rediscovered in value during the significant increase in lithium prices.

Since the core competitive advantage of sodium batteries is low cost, let me combine the latest research data to explain the cost of sodium batteries.

Sodium ion batteries are mainly composed of positive electrode, negative electrode, separator, electrolyte, and current collector, which is almost the same as lithium batteries. I will directly provide the cost structure diagram of sodium batteries.

The above diagram shows the current cost structure of sodium batteries, with the largest cost of battery cells coming from the four major components of positive electrode, negative electrode, electrolyte, and separator, which is similar to the cost structure of lithium batteries. Currently, the actual comprehensive cost of sodium batteries ranges from 0.7 to 0.9 yuan/WH. Of course, many sodium battery manufacturers claim to be able to achieve lower costs, such as 0.5 to 0.6 yuan/WH, but most of them are based on idealized cost calculations after scaling up, which is still not achievable.

As a comparison, let's take a look at the cost of lithium iron phosphate batteries at 400000 hours of lithium carbonate.

From the above figure, it can be seen that when lithium carbonate is 400000 yuan, the comprehensive cost of lithium iron phosphate batteries is about 0.77 yuan/WH, and the price of battery cells is about 0.7 yuan/WH. In terms of cost, the cost of lithium iron phosphate for the positive electrode accounts for nearly 50%. This is because lithium carbonate accounts for 85-90% of the cost of lithium iron phosphate for the positive electrode material of 140000 yuan/ton.

Overall, at a lithium price of 400000 yuan/ton, the price of lithium iron phosphate batteries is almost the same as that of sodium batteries, and sodium batteries have not shown significant economic benefits. The reason for this is analyzed as follows:

1) The main material industry chain of the current sodium ion battery technology system is not mature, and the price of hard carbon is 100000 yuan/ton, while the price of lithium iron phosphate negative electrode graphite is 50000 yuan/ton.

2) Due to the immature synthesis process, battery design, and manufacturing, the energy density of sodium ion batteries is relatively low, and the single GWh usage of each material is higher than that of iron lithium. For example, the membrane consumption of sodium ion batteries is more than 25 million square meters, which is 20 million square meters higher than that of iron lithium batteries. The price of sodium hexafluorophosphate is higher than that of lithium hexafluorophosphate.

The data above is also quite accurate. You can also refer to the selling price of domestic lithium iron phosphate batteries, as shown in the figure below. The average price of lithium carbonate in 2022 is around 400000 yuan/ton, and the high selling price of lithium iron phosphate batteries is 0.8 yuan/WH.

But now, with the price of lithium carbonate falling, the prices of other materials in the industry chain have also dropped significantly. The price of power type lithium iron phosphate batteries has fallen below 0.5 yuan/WH, with the latest price of 0.47 yuan/WH. However, the price of sodium battery cells is now about 0.67 yuan/WH. In this comparison, the advantage of sodium ion price ratio is completely eliminated.

The current price quotation for lithium carbonate is 170000 yuan/ton. If it drops to 150000 yuan/ton, the price of lithium iron phosphate batteries will be below 0.45 yuan/WH. The comprehensive cost of power type lithium iron phosphate will be around 0.5 yuan/WH, while energy storage type lithium iron phosphate batteries fell by 0.5 yuan/WH last month when the price of lithium carbonate was still 200000 yuan/ton. At a price of 150000 yuan/ton of lithium carbonate, the comprehensive cost of lithium iron phosphate will be around 0.45 yuan/WH.

Nowadays, the cost of sodium batteries is high, but after scaling up, how low can the cost be? Let's take a look at the cost of sodium batteries after large-scale cost optimization.

The above chart is basically the ideal cost for sodium power enterprises now. After large-scale production capacity and technological optimization, the price of sodium positive electrode materials has decreased from 70000/ton to 40000/ton, the price of negative electrode hard carbon has decreased from 100000 to 50000, and the price of electrolytes and other materials has been reduced to the same as that of lithium batteries.

The price reduction of this material is very significant, such as the cost of hard carbon, which is unlikely to be reduced by 50% within one or two years. Therefore, this price reduction process will not be short, involving technological breakthroughs in various links, ranging from 3 years to 5 years, in order to achieve this ideal state.

Based on this calculation, the comprehensive cost of sodium batteries is 0.5 yuan/WH. This price is actually similar to the current price of lithium iron phosphate batteries. The current price of lithium carbonate is 170000 yuan/ton. If the long-term equilibrium price of lithium carbonate is 150000 yuan/ton, the price of lithium iron phosphate batteries may still be lower than 0.5 yuan/WH.

So, in terms of cost, when lithium carbonate is below 150000 yuan, the cost-effectiveness advantage of sodium batteries is basically non-existent; When the price of lithium carbonate is around 200000 yuan/ton, the cost of sodium batteries is similar to that of lithium batteries; When the price of lithium carbonate is between 300000 and 500000 yuan/ton, the cost-effectiveness advantage of sodium batteries begins to become prominent, because at 400000 yuan/ton of lithium carbonate, the price of lithium iron phosphate batteries is around 0.7-8 yuan/WH, and the cost of sodium batteries is 0.5 yuan/WH, which still has advantages.

But it also depends on performance. Compared to other batteries in the same level, sodium batteries and lithium batteries still need to be better.

3、 Application field of sodium batteries

Firstly, it should be noted that sodium batteries are not currently used in mid to high-end vehicles due to their inferior performance compared to lithium batteries (at the same level), as they have differences in energy density and charging rate compared to lithium batteries.

The main application areas of sodium batteries now include two wheeled vehicles, A00 level cars, and energy storage, and for a long time, sodium batteries will only be used in these three areas.

Here's an explanation: in terms of price acceptance, A00 cars - energy storage and two wheeled vehicles rank from high to low in these three fields. In terms of entry difficulty, A00 cars - energy storage - two wheeled vehicles rank first.

The higher price of A00 cars is actually easy to understand, because cars also have high performance requirements. Only high-end sodium batteries can enter this market. As long as the performance is similar to lithium batteries, the price will not be much lower than lithium batteries. Now there are already car companies using it, such as the sodium electric QQ ice cream launched by Ningde and Chery, and the Yichi Yutu, a collaboration between Jiangling and Funeng Technology.

Energy storage batteries are generally lithium iron phosphate batteries, and competition is fierce. Energy storage batteries are a price war, so it is not easy for sodium batteries to enter the energy storage market. Especially for large energy storage, there is a requirement for cycle times, usually more than 6000 times. However, the actual cycle times of sodium batteries are only 2000-3000 times. Therefore, even if the price of sodium batteries is lower, it is difficult to enter the large energy storage market.

The energy storage market is a relatively professional market, and large-scale energy storage is dominated by enterprises. These enterprises will test battery performance, comprehensively consider price and cycle life. Therefore, in order for sodium batteries to have a share in the energy storage battery market, there must be innovation in technology.

Don't believe the current claim that sodium batteries can cycle up to 10000 times. These are all data measured in the laboratory through methods such as improving materials and changing testing modes. For example, in the three routes of sodium batteries, polyanion batteries can be added with more stable substances, which can achieve high cycle times under significantly reduced energy density conditions; For example, during testing, if you are not satisfied with filling up and filling up, these are all experimental methods, and the reality is not to do a research paper, so you need to respect reality.

In the two wheeled vehicle market, the technical requirements for batteries are actually the lowest. They do not require a long cycle life (1000 cycles are acceptable), and low energy density is not a problem. After all, lead-zinc batteries were used before (with an energy density of about 40WH/KG), and sodium batteries can meet the requirements of two wheeled vehicles in terms of performance. As long as the price is cheap enough, this market will be large because there are over 70 million two wheeled vehicles sold globally, This market is enough for sodium batteries. If sodium batteries can achieve 0.5 yuan/WH, the two wheeled vehicle market is still very competitive.

summary

1、 Sodium batteries are products of high lithium prices, and this wave of sodium battery investment fever also emerged in 2021 when the price of lithium carbonate exceeded 200000 yuan/ton. From a cost perspective, if the price of lithium carbonate is below 200000 yuan/ton, even if sodium batteries reach the ideal cost level within 3-5 years, they still do not have an advantage. The most suitable environment for investing in sodium batteries is high lithium prices, and sodium batteries will always exist as a backup tire for lithium batteries as a supplement.

2、 The sodium battery industry chain is not yet mature. At present, various links in the industry chain, such as negative electrode hard carbon, are mainly supplied by Betray, which is a leader in lithium battery negative electrodes. The main supplier of sodium hexafluorophosphate is also a leader in lithium battery electrolytes such as Tianci. These materials are very mature for the lithium battery industry, and the cost can be very low. However, the sodium battery industry is just starting and there is not much quantity, Opening a single production line to produce a single product is not cost-effective for these enterprises, so although the raw material cost is lower, the selling price is actually higher because it compares to the overall cost.

3、 The technological system also has a siphon effect. There is a huge gap in investment between lithium and sodium batteries. Each manufacturer of lithium batteries has hundreds of researchers, while companies like CATL and BYD have tens of thousands or even tens of thousands of researchers, with R&D investment exceeding 10 billion yuan. Moreover, the lithium battery market is large, and when companies make money, their reinvestment capital also increases accordingly; Manufacturers of sodium batteries, such as Chuanyi Technology, are considered top companies. At the beginning, there were only over 10 people involved in research and development. The R&D investment cannot be compared to that of lithium batteries, and the difference in investment is too significant.

This is the siphon effect of the technological system, which leads to the rapid evolution of lithium battery technology. Two years ago, it was BYD's blade battery, and last year it was Ningde's Kirin battery. From lithium iron phosphate to lithium manganese iron phosphate, industrialization took only one and a half years. Therefore, lithium batteries, as the mainstream track, have gathered a large number of talents and funds, accelerating the pace of evolution.

4、 After the lithium price enters a downward cycle, the popularity of sodium batteries will gradually decrease. This is a very realistic choice, because sodium batteries were originally intended to be cheaper. When lithium prices fell, it was found that lithium iron phosphate batteries were cheaper and had better performance. Those customers who were originally planning to buy sodium batteries would not choose products with better cost-effectiveness? So, it is estimated that those nano battery manufacturers who are preparing to increase production capacity now need to calmly consider whether to increase production capacity, as there may be no one buying the products even if they do. Chuanyi Technology rose from 10 yuan to 51 yuan in July 2022, and now it has dropped from 54 yuan to 18 yuan in just six months. In fact, the rise and fall of Chuanyi's stock price represents the market's reaction to lithium prices, as the main reason for investing in sodium power is high lithium prices.

5、 Is there a future for sodium batteries? Yes, I am a technologist. I believe that sodium battery technology will continue to improve and costs will continue to decrease, but this requires time and a suitable environment. It takes 3-5 years to achieve technological progress and cost reduction, and the suitable environment is for lithium carbonate prices to exceed 200000 yuan/ton. Now, the market value of sodium battery company Chuanyi Technology has dropped to around 5 billion yuan. In a few years, when the next lithium price cycle comes, the global shipment scale of lithium batteries will reach 2000-3000GW, and sodium batteries will have a 5% share of over 100GW, so there is still room, and it is not small.

The ideal investment scenario is to buy lithium mining stocks at the bottom of the lithium price cycle, and then buy sodium electric stocks when lithium prices rise. For example, if you buy lithium stocks at the bottom of this lithium cycle, and wait for lithium prices to rise again, your lithium stocks will rise a lot. At first glance, sodium stocks are still at the bottom, so buy sodium stocks. If sodium stocks also rise four times in half a year like Chuanyi Technology did before, sell them, leave gracefully, and hide achievements and fame... The above is my daydream, don't take it seriously