Shulou(Shulou.com)11/24 Report--

Finally, the sodium-ion battery is coming!

A few days ago, the China Chemical and Physical Power Industry Association announced that from October 8 to November 7, the whole network solicited opinions on the General Specification for Sodium Ion Batteries. The general specification is mainly applicable to automotive power batteries, energy storage and other fields. If the progress is smooth, it is expected to be released and implemented around November.

Domestic battery enterprises such as Ningde Times, BYD, Huayang, Chuanyi Technology and Weike Technology have already entered the sodium ion battery market, among which Ningde Times has continuously made technological breakthroughs.

However, electric vehicles on the market are basically lithium batteries, and a small number of high-end models are trying new semi-solid batteries and solid-state batteries. Do we really need sodium-ion batteries?

The future of electric vehicles, can not be without sodium ion batteries The current electric vehicles commonly used batteries are mainly two kinds, namely lithium iron phosphate batteries and ternary lithium batteries, the main difference between the two batteries is that lithium iron phosphate batteries are lower in cost, relatively high in safety, but the energy density is too low, except BYD, other car companies basically only low-end models will be equipped with lithium iron phosphate batteries.

The advantage of ternary lithium batteries is that they have higher energy density, while the disadvantage is that they are slightly more dangerous and costly, and are more prone to deflagration than lithium iron phosphate batteries.

However, the theoretical energy density of ternary lithium battery will not exceed 500Wh/kg at most, and Tesla's 21700 battery energy density can reach 300Wh/kg, which is the limit level of current power battery. According to 100 kilometers of power consumption 15 degrees calculation, 1000 kilometers of car life, battery weight will be as high as 500kg or more.

Electric vehicles are much slower to charge than fuel vehicles, and even if the number of charging piles is equal to that of refueling guns, it is more likely to cause congestion queues, so car owners generally have endurance anxiety. The endurance of domestic mainstream electric vehicles is usually 450 km ~650 km, which cannot solve the anxiety of vehicle owners.

Therefore, many car companies and battery companies have been developing solid-state batteries. The lower limit of the energy density of solid-state batteries can almost be said to be the upper limit of the energy density of ternary lithium batteries. A casual search of relevant reports shows that the solid-state battery jointly developed by Enli Power and Softbank has a relatively low energy density compared to other similar products, reaching 300Wh/kg, while the solid-state battery developed by NASA has an energy density of 500Wh/kg.

It seems that everything is very good, except for the slightly higher cost, but we may have overlooked a problem, whether it is lithium iron phosphate battery, ternary lithium battery, or solid-state battery, lithium element is inseparable.

According to the United States Geological Survey (USGS), there are only about 98 million tons of lithium ore on Earth (2022 data). Although half of the proven resources are in the hands of Chinese companies, we must admit that this lithium mine resource is simply not enough for the global automotive industry to achieve an electric transformation. For this reason, Tesla built its own lithium ore refining plant to improve the utilization rate of lithium ore resources.

Sodium ranks sixth, more than 400 times lithium. Rich in content and easy to mine, the cost of sodium-ion batteries is naturally much lower than lithium batteries. From the perspective of cost and environmental protection, sodium-ion batteries are the best choice for low-cost and high-endurance models.

Sodium-ion battery, hope for low cost and high endurance? In addition to low cost, sodium-ion batteries have two advantages: higher safety and better performance at low temperatures. Even in cold northern areas, there is no need to worry about low winter temperatures and a sharp drop in electric vehicle life.

Sodium-ion batteries seem to be the hope of achieving low cost and high endurance, but sodium-ion batteries still need to solve a problem, that is, the energy density is too low!

At the 15th Shenzhen International Battery Technology Exhibition in May this year, Tuobang released a sodium-ion battery with an energy density of only 120Wh/kg, which is expected to increase to 160Wh/kg by 2025, even inferior to lithium iron phosphate batteries.

According to the data released by the second sodium-ion battery industry chain and standard development forum held in July, the average energy density of 17 sodium-ion battery enterprises participating in the evaluation is only 104.1Wh/kg, which can be said to be terrible and temporarily not suitable for electric vehicles.

Ningde Times, the power battery enterprise with the highest installed capacity in the world, invested heavily in the research and development of sodium ion battery. The first generation of sodium ion battery was released in 2021, with energy density of 160Wh/kg. At the Shanghai Auto Show, Cherry, Chery and other automobile enterprises announced that in the fourth quarter of this year, they will launch cars equipped with sodium ion batteries in Ningde era. The energy density of the second generation sodium ion batteries in Ningde era can reach 200Wh/kg.

However, 200Wh/kg is obviously not enough to achieve 1000 km battery life and solve the anxiety of vehicle owners. Also calculated according to the energy consumption of 100 kilometers of 15 degrees, the sodium ion battery pack with 1000 kilometers of endurance weighs up to 750kg. An ordinary B-class car weighs about 2000kg. If it is a medium-sized SUV, it weighs about 2500kg. The battery ratio is too high.

Not only that, but batteries also take up a lot of space. The energy density of the second generation sodium ion battery in Ningde era is calculated according to volume, which is about 350Wh / L, and the 100 km battery life requires about 0.43 m ³ space.

Now some new energy vehicles use the sky curtain design, because the bottom battery takes up too much space, if the traditional skylight design, then the head space is likely to be too crowded. The weight of the battery will also affect the battery life, too heavy car, you need a larger capacity battery, in order to achieve the same battery life, take up too much space, and will reduce ride comfort.

The urgent task of sodium-ion battery is still to improve the energy density, which is expected to reach 300Wh/kg, so that it is possible to achieve 1000 km long endurance on ordinary models.

As far as the current situation is concerned, sodium-ion batteries have the opportunity to gradually replace lithium iron phosphate batteries, and in the future, they will achieve a three-legged situation with ternary lithium batteries and solid-state batteries.

Power battery market pattern, lithium iron phosphate tears say goodbye? After the commercial use of sodium-ion batteries, the status of lithium iron phosphate batteries will inevitably be very embarrassing, because the battery's low cost, high safety advantages, sodium-ion batteries all have, and better performance.

Chen Liquan, academician of the Chinese Academy of Engineering, said that after the large-scale commercial use of sodium-ion batteries, the cost will be more than 20% lower than lithium iron phosphate batteries.

Xiaotong believes that the distribution of power batteries in the domestic automobile industry in the future is likely to appear sodium-ion batteries, ternary lithium batteries, solid-state batteries tripartite situation. Among them, sodium-ion batteries replace the existing status of lithium iron phosphate batteries, mainly used in models within 150,000 yuan, ternary lithium batteries are mainly used in high-end models of 150,000 yuan to 350,000 yuan, and solid-state batteries are used in high-end models of more than 350,000 yuan.

It should be noted that due to space and weight constraints, sodium-ion battery electric vehicles are unlikely to have a 1000-kilometer version, and are expected to last between 400 km and 600 km.

Ternary lithium batteries may have a small number of models with a range of 1000 kilometers, but the general range is expected to be 550 - 800 kilometers. The battery life of solid-state battery electric vehicles will be more than 700 kilometers, and it is very likely that there will be many models with 1000 kilometers of battery life.

Of course, these predictions are all domestic vehicles. The joint venture vehicles and domestic vehicles have different strategies and do not care so much about cost performance, so there may be some completely different results from domestic vehicles.

This article comes from Weixin Official Accounts: Tram Tong (ID: dianchetong233), Author: Lost Soul Guide

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