The lithium battery comes in different shapes and sizes. These shapes and sizes can be customized as per the requirement and the application.
The electric vehicles we are seeing these days use these batteries, as do your e-rickshaws, and even the batteries used within the solar system at your home are equipped with lithium batteries.
The uses may differ, but the production process for the lithium battery remains the same. In this article, we will explain the complete manufacturing process of a lithium battery, what components are used, and step by step what it takes to manufacture a lithium battery.
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Components Required for Lithium Battery Manufacturing
Firstly, let’s understand the components required to make a lithium battery.
Lithium batteries can be of different sizes and types. Based on their application and your requirement you can choose the different types of battery body and cells.
Below, we have shared a list of all the components required to manufacture lithium batteries.
- Lithium Cells such as
- Nickel-magnesium-cobalt lithium-ion cells, or NMC cells
- Lithium Ferrophosphate or LFP cells
- Prismatic Cells
- Cell Holder
- Nickel Strips
- Battery Management System or BMS
- Wires such as DC wires, sensor wires, etc.
- Barley paper
- Tapes such as FRP tape, captain tape, filament tape, double-sided tape, etc.
- Different types of bodies such as stainless steel, mild steel, plastic containers, epoxy fiberglass body, FRP sheet body, heat-shrink sheet body, etc.
Almost all of these components can be made in India except the cells. These lithium cells are mostly imported into India and used in different projects as per different applications.
Machines Required for Lithium Battery Manufacturing
A lithium battery can be made manually but automated machines can fasten the process and increase the production.
Below is a list of all the machines required to manufacture lithium batteries.
- Cell Grading Machine
- Cell Sorting Machine
- Auto-insulating Sticker Pasting Machine
- CCD Inspection Machine
- Automatic Spot Welding Machine
- Automatic Laser Welding Machine
- Battery Testing Machine
Lithium Battery Manufacturing Process
Now let’s talk about the lithium battery manufacturing process.
Step 1 – Cell Grading
The first stage is known as cell grading. In this process, a lot of cells are plugged into cell grading machines. These machines charge the cell completely and then discharge it.
This test is done to categorize cells on the basis of their capacity. As we said, these cells are imported from some 3rd-party plant in China, so there are differences in their capacities.
For example, if we have these cells at 3.2 volts, the further we go into decimal places (3.22, 3.24, and 3.27), the more difference we will see. These are all the same 3.2 volts but will have minor differences when looked at further decimal places.
If you want to create a quality lithium battery, then there should be no difference. If there’s a difference, then it reduces the battery’s life.
That’s why these cells are tested multiple times via charge, discharge, capacity, individual cell report, and their life cycle and group the same category of cells together without even minor differences.
This process takes a minimum of 6 hours and is monitored by computer.
Step 2 – Cell Sorting
The next step is called cell sorting.
This process is quite similar to cell grading, but here they are sorted on the basis of voltage and internal resistance. Cells are put into this machine, and then it sorts the cells into multiple batches.
Small manufacturers do not follow processes such as cell grading and cell sorting and directly make batteries out of the cells, which reduces the battery life.
Hence, whenever you are planning to buy a lithium battery, you should check the assembly process of the respective brand.
Step 3 – Applying Barley Paper for Insulation
Barley paper is an insulation paper that is applied to the cell so that the battery wouldn’t have any internal short circuits.
It can be done manually, but there’s an automated machine to do that called the “auto-insulating sticker pasting machine.”
Cells are put into this machine, and it covers them with barley paper, so they become ready to form batteries.
Step 4 – Arrange the Cells in the Cell Holder
The next step is to arrange them together with the help of the cell holder. These are little square boxes connected to each other. You can combine as many cells as you need.
It takes two layers of cell holders, one at the bottom and another at the top. In this, you can either connect cells in parallel or connect them by interchanging their terminals.
You can make multiple customized patterns with the help of the cell holder.
Step 5 – Inspection of the Cells Before Soldering
Once your cell combination is ready, you have to shoulder them, but first, they are checked visually to make sure the positive and negative terminals are set correctly.
Because if there’s even a single cell misplaced, then it could make the whole battery dysfunctional. A CCD inspection machine is used to check this.
This process is quite simple – you have to put your battery pack here, and the machine analyzes it via multiple digital cameras and processes its image. It checks a lot of data, like pixels, brightness, color, etc. After that, you get the output on the attached screen.
This process can be done manually, but machines accelerate the process and improve accuracy.
Step 6 – Soldering or Welding The Cells
Once they pass the CCD test, they’re ready to be welded.
Spot welding is a process where the negative and positive ends of cells are connected by welding them along the nickel strips. This can be done manually or with the help of a machine.
Automatic Spot Welding – The machine is called an automatic spot welding machine. Once you put your battery pack into this machine, it’s computerized to weld them together automatically.
Manual Spot Welding – In a manual spot welding machine, the operator has a foot paddle that is used to weld, and the battery pack is adjusted manually during the process.
Automatic Laser Welding – There’s an automatic laser welding machine that is used to weld big cells. In this process, a battery is placed in the machine with the nickel strip, and a computerized arm is analyzing it before welding. You can see this process on a computer screen, and once done, you get your final battery pack.
Each welding method has different benefits and limitations. It depends on what you’re welding; based on that, different methods are chosen.
Step 7 – Arrange the Lithium Cell Strings
Once the welding is done, the battery gets put into a basic pack that is made of epoxy sheet, insulator paper, and different types of tape.
This is not the actual battery body, but it’s done before applying the BMS.
Step 8 – Connecting a BMS
The next step is to apply a Battery Management System or BMS. It’s a computer circuit that is connected to the multiple strings in the battery. It monitors the cells, their charging and discharging properties, their heating, and other such issues.
BMS is known to be the brain of the battery and works by optimizing, protecting, and monitoring the battery’s health.
There are two types of BMS available on the market;
Normal BMS – It’s a normal BMS whose sensor wires connect to the battery.
Smart BMS – Just like a normal BMS, a smart BMS also has multiple sensor wires that connect to the battery, but it also has a Bluetooth transmitter device that connects to your mobile and sends the data to your phone.
The BMS is used as per the requirements of the client or product.
Step 9 – Lithium Battery Testing
Now that the lithium battery is ready, it goes through a testing phase to test whether the battery is functioning properly or not.
For that, the lithium battery is put into a battery testing machine, which charges and discharges the battery completely and provides a computerized report of the tested BMS and battery.
Once the battery passes this test, the battery is ready to be used, but not before it is put into either a soft or hard body as per requirements.
Step 10 – Putting the Lithium Battery in a Body
Talking about the battery body, to keep the body weight low, epoxy sheets and heat-shrinkable sheets are used.
When a hard body is required, then stainless steel, mild-carbon steel, and plastic containers are used.
After keeping the lithium battery in a respective body, the battery is all set to be packed and delivered.
Conclusion
This was all about the lithium battery manufacturing process. You can use the battery for any applicable purpose, like in electric vehicles, e-rickshaws, and even in solar projects.
These lithium batteries can be used for any purpose, and all of them have the same manufacturing process.
Do check out our other articles on solar panels and lithium batteries. Shared a list below.