How does a sodium-ion battery come into being?

Dual-carbon background, with the new energy vehicle market large-scale outbreak, large-scale energy storage applications in the planning of various regions have been put on the agenda.

Lithium-ion batteries, which originally relied heavily on imports, will face a shortage of resources.

Sodium-ion battery is a kind of secondary chemical battery with many advantages, including abundant resources, low cost, high energy conversion efficiency,

long cycle life, high safety, excellent high and low temperature performance, good high rate charging and discharging performance, and low maintenance costs.

It is expected to complement lithium-ion batteries in large-scale electrochemical energy storage and low-speed electric vehicles.

At present, both domestic and foreign countries have begun to launch the industrialisation of sodium-ion battery layout, sodium-ion batteries already have a large-scale industrialisation of the market conditions and technical conditions.

So, how is a sodium-ion battery born?

First of all, we first understand the composition of sodium-ion batteries, the principle of operation and mainstream technology routes.

Sodium-ion battery consists of positive electrode materials, negative electrode materials, electrolyte and diaphragm, etc., the working principle and lithium-ion batteries are similar, all belong to the ‘rocking chair’.

When charging, sodium ions are discharged from the positive electrode material and embedded in the negative electrode material through the electrolyte, while electrons move from the positive electrode to the negative electrode through the external circuit, thus maintaining the charge balance of the system.

According to the classification of cathode materials, there are currently three technical routes for sodium ion batteries with initial industrialisation prospects: layered transition metal oxides,

polyanion compounds and Prussian blue analogues. Among them, the advantages of layered transition metal oxide material are simple preparation method, high specific capacity and energy density,

The disadvantage is that it is easy to absorb water or react with air, which has an impact on the stability of the material structure and electrochemical performance.

The design and production of sodium-ion battery, different material systems and structural types of sodium-ion battery electrode manufacturing process is basically the same, the difference is that different technologies of sodium-ion battery electrode manufacturing process is basically the same.

The difference lies in the different technologies of sodium-ion battery packaging form, internal structure is different, the assembly process is different.

Take sodium-ion soft pack battery as an example, the process can be roughly divided into three parts.

1. the front-end electrode manufacturing process, including electrode paste preparation, electrode coating, roller pressing, vacuum drying of the pole piece, pole piece die cutting, etc.; 2. the back-end assembly process.

2. the back-end assembly process, including stacking, welding, shell encapsulation, vacuum drying, liquid injection and so on.

3. into the sorting process, including pre-sealing, into the second package, secondary encapsulation, capacity screening, etc..

In addition, the key step in the design and production of sodium-ion batteries, the formation of the sorting process based on the appearance of the battery structure and capacity, different formation of different environments, the selection of the folder has a difference.

The production line of sodium-ion battery and lithium-ion battery is basically similar, the difference is that sodium-ion battery can use aluminium foil as anode collector.

Thus, both positive and negative electrode lugs adopt aluminium electrode lugs, therefore, under certain circumstances, the existing lithium-ion battery production line can be used for the production of sodium-ion batteries with a slight modification, thus significantly saving the initial sodium battery enterprises.

Therefore, under certain circumstances, the existing lithium-ion battery production line can be slightly modified for the production of sodium-ion batteries, which can significantly save the initial cost of sodium input for battery enterprises.