Briefly discuss the characteristics and application fields of sodium ion batteries

　　After CATL released a sodium ion battery that can be truly industrialized, people from all walks of life are very interested in this rechargeable battery using a new type of cathode material. Let's briefly talk about the characteristics and application areas of sodium ion batteries.

　　A: In terms of battery capacity performance, sodium ion is higher than lead-acid battery and lower than lithium iron phosphate battery

　　Similar to the working principle of lithium-ion batteries, sodium-ion batteries mainly rely on the movement of sodium ions between the positive electrode and the negative electrode. This is the mainstream secondary battery technology currently on the market.

　　At present, the main competitive products in the sodium-ion battery industry are lithium manganate batteries, lithium iron phosphate batteries, lead-acid batteries, and cascaded lithium batteries. By calculating the difference in energy density between the positive and negative electrodes of sodium ions, it can be concluded that under the same technical conditions, the energy density of sodium ions is about 0.7-0.8 times that of lithium manganate batteries and lithium iron phosphate batteries.

　　PS: Energy density refers to the amount of energy stored in a certain space or mass material. It is used to measure the most suitable battery and compare the amount of electricity stored by a battery per unit volume.

　　B: From the perspective of battery cycle life, sodium ion batteries are much higher than lead-acid batteries, but lower than lithium iron phosphate batteries

　　In the industry, the cycle life is generally calculated by the number of cycles of full charge and discharge of the battery. In the process of use, an irreversible electrochemical reaction occurs inside the battery, which leads to a decrease in capacity, such as the decomposition of the electrolyte, the loss of active materials, the collapse of the positive and negative structures, and so on.

　　At present, the cycle life of sodium-ion batteries is much higher than that of lead-acid batteries, but there is still a gap between lithium batteries. At the same time, the self-discharge ratio is relatively high, reaching 5%/month.

　　C: From the perspective of battery safety, sodium ion batteries have better thermal stability

　　There are frequent fire accidents of lithium batteries worldwide, and frequent fires of electric vehicles and energy storage. According to incomplete statistics, there were 32 fires and explosions of energy storage power stations worldwide from 2011 to 2021, of which 26 accidents used ternary lithium-ion batteries.

　　The electrochemical performance of sodium ion batteries is relatively stable, and the safety test performance is better than that of lithium ion batteries. At present, the sodium-ion battery has passed the inspection of the China Automotive Industry Center. It does not emit smoke, fire, or explode during acupuncture, and does not catch fire or burn when subjected to short circuit, overcharge, over-discharge, and squeezing experiments. This shows that sodium ion batteries have better thermal stability.

　　D: Sodium ion batteries are expected to be used in two fields, energy storage and power

　　From the perspective of battery capacity performance, battery cycle life and battery safety of sodium-ion batteries, sodium-ion batteries are expected to be used in two fields of energy storage and power in the future:

　　In the power field, sodium ion batteries will be used in two-wheeled vehicles and electric vehicles. In the field of two-wheeled vehicles, due to the relatively low energy density and high safety characteristics of sodium-ion batteries, it is expected to gradually replace lead-acid batteries. Among them, electric vehicles are expected to be used in conjunction with an integrated system of sodium-ion batteries and lithium-ion batteries.

　　In the field of energy storage, it is the consensus of governments around the world to explore and carry out research and demonstration applications of hydrogen storage, heat storage and other innovative energy storage technologies based on demand. Therefore, under the impetus of policies, sodium ion batteries are expected to accelerate their application in energy storage on the grid side, power consumption side and power generation side.

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