There are three main reasons why sodium ion batteries cannot replace lithium ion batteries temporarily!

　　The material structure of the early sodium-ion batteries would be destroyed during the cycle, causing the battery capacity to decay rapidly, and the final performance was that the cycle life was too low. Therefore, the CATL aimed at this point, and the sodium battery developed with a new idea was born. The bulk structure of the material is designed to solve the problem of rapid capacity attenuation during the cycle.

　　In terms of negative electrode materials, a unique material has been developed, which has the characteristics of high gram capacity, easy deintercalation, and excellent circulation, and optimized the suitable electrolyte. In this way, the sodium ions can travel freely between the positive and negative electrodes without excessively attenuating energy. And the production line of lithium-ion batteries can also be used to produce sodium batteries, which effectively controls the cost.

　　After technical optimization, the single energy density of sodium-ion batteries has reached 160Wh/kg, almost reaching the standard of lithium iron phosphate batteries (150-210Wh/kg). Charging at room temperature for 15 minutes, the power can reach 80%; and in a low temperature environment of minus 20 ℃, there is still a discharge retention rate of more than 90%. At the same time, the system integration efficiency can reach more than 80%.

　　The keywords "fast charging", "low temperature resistance" and "high integration efficiency" directly hit the current pain points of lithium batteries, and also let people see the hope of solving the problem of new energy vehicles' battery life, as well as new development ideas for power batteries in the future.

　　So, is there any hope for sodium batteries to occupy the market share of lithium batteries in the field of power batteries or even eventually replace lithium batteries? Although the current sodium batteries have shown some better performance than lithium batteries, it is still too early for sodium batteries to "make a big push" in the field of power batteries.

　　A: First of all, one of the intrinsic properties of sodium batteries is difficult to change, that is, low energy density.

　　Due to the physical reasons of sodium ions, it is difficult for sodium batteries to achieve the energy density of lithium batteries under the same technical conditions. Although the energy density of sodium batteries released by the CATL is close to that of lithium iron phosphate batteries, it should be known that most of the high-end areas of power batteries now use ternary lithium batteries. The energy density of ternary lithium batteries is very high. The cell energy density of the cell battery is generally above 200Wh/kg, and the high nickel system even exceeds 250Wh/kg, which has a significant lead over sodium batteries.

　　Therefore, considering only energy density, sodium batteries are expected to replace lead-acid and lithium iron phosphate batteries in the main start-stop, low-speed electric vehicles, energy storage and other markets, but they are more difficult to apply to electric vehicles and consumer portable electronics. Lithium batteries in the two major areas will remain the mainstream choice.

　　B: Secondly, the current cycle life of sodium batteries is still shorter than that of lithium batteries.

　　Due to the relatively large sodium ion radius, a large amount of insertion or extraction of sodium ions will cause large volume expansion or contraction of the material, which easily induces irreversible structural changes in the electrode material, so that the high-capacity sodium ion battery exhibits insufficient cycle life. According to statistics, the cycle life of mainstream sodium-ion batteries is only 1000 to 1500 times, and the products of individual manufacturers can reach 3000 times. The most advanced sodium battery can barely match the ternary battery, but it is also far behind the lithium iron phosphate battery.

　　C: Finally, the production technology of sodium batteries is not yet mature and the industrial chain is incomplete

　　This is the deadliest shortcoming at this stage, which leads to the cost of sodium batteries and does not have an advantage over lithium batteries.

　　In this regard, the relationship between sodium batteries and lithium batteries is not a simple "replacement" relationship. In the field of power batteries, there is indeed a certain degree of competition between the two, but they also have their own more biased areas. In the future, with the gradual maturity of sodium battery technology and the formation of the industrial chain, as well as the increasing shortage of lithium resources, sodium batteries are expected to replace lithium batteries in the low-speed and low-end fields of power batteries, while lithium batteries will continue to play effect in the high-speed and high-end fields.

　　Lithium-ion battery (LIB) has become the main energy storage solution in modern social life. Among them, lithium iron phosphate battery is a perfect replacement for lead-acid batteries, and it is the first choice for grid-connected peak shaving, off-grid energy storage, photovoltaic energy storage, UPS, data center and other industries.