The battery cells are the primary electrochemical unit, offering an electrical power source. It operates through immediate chemical power transformation.
Moreover, battery cells have lighter weight, compact, and affordable features. They supply power in a short time.
Main Components and How They Work
Cathode. It is where the electrons flow through a circuit. To which the device is connected. In other words, it’s conventional current discharge.
Within the battery, there is a chemical reaction. It takes place close to the cathode and employs electrons generated by the anode. Moreover, the circuit is how electrons get into the battery to the cathode.
Electrolyte. An electrolyte is usually either in the form of a liquid or a gel. It enables the transferring of ions for both the anode and cathode’s chemical processes.
Additionally, it restricts the two components’ flowing electrons, allowing an easy way into the external circuit. An electrolyte is an essential component of the battery.
Anode. Opposite from electrons, electrons flow into the anode. The chemical reactions of electrolytes and anode generate electrons in a battery.
These electrons cannot get in their way to the electrolyte even though it moves into the cathode.
Classifications of Battery Cells
Primary cell (dry). This type of battery is challenging to recharge. It can only be used once and disposed of when discharged. In most cases, the primary cells utilize an absorbent material electrolyte.
Secondary cell (wet). A type of battery that is electrically rechargeable. It regains back the actual condition bypassing the flows in to reverse direction.
Reserve cell. The function of this cell represents an effective elimination of self-discharge. Although this battery is mainly for single usage, they are helpful in many heavy applications.
Fuel cell. This fourth cell has the same structure as an actual battery. But differ in the sense that it does not have an integral component. Yet, it possesses the capability that highlights exceptional features.
Battery Category By Application
Vehicles
The battery for vehicles is convenient to use and has a simpler industrial battery version. They are particularly manufactured and assembled for motorcycles, electric cars, and many other vehicles.
Household
Household batteries are applicable for home appliance usage, including clocks, cameras, etc. There are two subsections for these batteries,
- Rechargeable
- Non-rechargeable
Industrial
Industrial batteries are formed to support heavy-duty machines. These batteries are designed for railroads and other projects.
By Shapes/Types
a) Coin
Round shape cells are ideal applications that require low power and space. Although they are small, it allows them to fit in specific places.
b) Cylindrical
With a mechanism for pressure alleviation, these cells’ form has an advantage. One of them is that they can withstand severe internal pressure without breaking.
c) Prismatic
The structure has mechanical stability. It has a flat rectangular form but varies in size. That means it has no standard size but shape.
d) Pouch
These shaped cells are light in weight and flexible. Its bag-form design allows space when the battery swells. The possibility of that situation is potential after a thousand cycles.
Battery Cell Parameters
| Sizes | NominalVoltage | Dimension | Weight
(NiMN gm) |
|
| Depth | Height | |||
| AA | 1.5V | 14.5mm | 50.5mm | 26 |
| AAA | 1.5V | 10.5mm | 44.5mm | 13 |
| AAAA | 1.5V | 8.3mm | 42.5mm | 10 |
| A23 | 12V | 10mm | 28.2mm | 8 |
| C | 1.5V | 26.2mm | 50mm | 72 |
| D | 1.5V | 34.2mm | 61.5mm | 140 |
| 9V | 9V | 25mm | 15mm | 43 |
| CR123A | 3V | 17mm | 33.4mm | 17 |
| CR2032 | 3V | 20mm | 3.2mm | 3 |
Factors to Consider Choosing Battery Cells
-
Power usage
Because of this, specifying its ideal use and limitations is easy.
-
Size
Size should take into consideration because it depends on the usage.
-
Temperature ranges
This factor is crucial to regard as it can cause issues.
-
Standby operation
It sets if the battery has features for emergency backup sourcing.
-
Performance
Battery cells’ performance needs to confirm their capacity.
-
Form
That enables the battery to be used in specific applications.
-
Charging Cycle
It determines how long will the battery cell last.
Standard Battery Cells
Single-Use
| Type | Features | Applications |
| Zinc-carbon |
|
|
| Zinc-silver oxide |
|
|
| Zinc-manganese dioxide |
|
|
| Lithium-manganese dioxide |
|
|
Rechargeable Cells
| Type | Feature | Application |
| Lead-acid |
|
|
| Nickel-cadmium |
|
|
| Nickel-metal hydride |
|
|
| Lithium-ion |
|
|
Battery Cells in Series and Parallel
Series Connected
They are called series batteries when the battery cells’ positive side is successively linked to a negative terminal.
The battery’s overall emf is the connected arithmetic summation of each cell series. Although the total current discharged does not surpass the emitted charge single cells.
Parallel Connected
When battery cells’ positive and negative terminals are in the same manner of position, it’s called a parallel battery. The cells are connected in similar forms, particularly parallel.
Therefore, the emf of a single cell is the same. Then the connected parallel form meant that each cell has an equal emf.
How They Manufacture
Knowing the battery cell manufacturing procedures will also inform everyone of their limitations and advantages.
Electrode Production
- Mixing
Before delivering into the coating machine, the cathode and anode components are blended. This method spends time to guarantee the slurry’s homogeneity.
For the cathode, active, conductive, and carbon additive materials are blended.
For the anode, polymer binder, live materials, and conductive materials are mixed.
- Coating
Through constant coating techniques, the components are coated individually. Cathodes are coated using aluminum element electrodes. The polymer binder bonds the two components into the aluminum and copper electrodes appropriately.
- Drying
The coated electrodes are quickly dried after the process. A constant infrared heating procedure achieves such outcomes and retakes the solvents.
- Calendering
A process of electrode rolling with managed thickness and solidness. This process also helps prevent cracking issues.
Cell Assembly
- Slitting
On slitting time, the electrodes have a 1.5m typical width. At this point, the lengthy electrodes are cut into the necessary width, suitable for final cell measurements.
Smooth edges are essential to achieve at slitting process to prevent separator issues and short-circuits.
- Last Drying
Before cell assembly, the produced electrodes need to be dried again. That helps get rid of water and solvent contents.
- Cutting
After fulfilling the last electrode forms, the tags and other parts should be cut. At this time, electrodes should be formed according to the final shape accurately. That helps achieve an efficient cell assembling process.
- Twisting or Stacking
Twisting components to reach spiral shapes is perfect for cylindrical cells. However, pouch cells require stacked electrodes.
- Terminal Welding
Terminal welding is a process of joining anodes to negative terminals and cathodes to positive ones. It is critical to have expertise in doing the such process. Since cell and busbars, welding may cause internal damage.
- Enclosing
The rolled or packed electrode layers are filled into the pouch or can. Canned or enclosed cells will be based on the cell formats.
- Ensures clean can
- Achieves roll or stack without issues
Cell Finishing
- Filling
The filling process filled the dry cell with electrolytes. There’s a vacuum part that is formed for a cell. Thus, there is also a fixed electrolyte amount transferred to the cell. The partial ones support the distribution process while wetting the cells’ layers.
Moreover, the formed electrolytes are dispensed according to the required liquid level. After and prior to the filling procedure, it is also important to inspect the cells’ weight.
- Forming & Sealing
Charging the cells may produce gases in them. The formed gases are delivered prior to cell sealing. Forming and aging procedure will be finished in about 3 weeks.
At the formation moment, the Solid-Electrolite Interface grows. This SEI help avoids electrolyte permanent deterioration and secures the anode against overloading.
- Aging
For an extended time, the cells are stocked at a managed temperature. That enables the SEI to equalize.
The aging step bonds the cell for a long period. It also gives great value, thus links to the funds.
- Last Control Inspection
Some control inspections are done before the shipment. That includes
- Mass inspection
- Leak inspection
- Thickness assessment
- Cell trimming
- Dimension inspection, etc.
Balancing Battery Cells
Balancing active and passive cells helps maintain an excellent battery SoC. It helps prolong their cycle life and gives extra layers. That ensures heavy discharge and overcharging resistance to the cell.
Passive-balancing passive cells achieve an equal state of battery charging. It is done by dissolving extra bleed resistor charge, yet doesn’t prolong the systems’ life.
Active- It is a more complicated balancing method. It reallocates the discharge and charge results for battery cells.
Unlike passive ones, active balancing improves the system’s working time and decreases the charging period.
Typical Failures of Batteries
Electrical Cell Over-stress
Battery cells are tactful components in terms of electrical overstress. The overcharged cells’ elements may cause heat, forming electrical dangers, like fire.
That is why having control circuits can help prevent such occurrences and secure efficient cell performance
Mechanical Over-stress
Battery cell damage due to mechanical stress can cause quick battery failure. Their failures will always depend on various strands, including cell age, temperature changes, and charge conditions.
Cell Internal Damage
Cell internal damages happen because of production defects inaccurate cell structures, dirty raw materials, and damaged separators.
It is recommended to have quality management systems to guarantee the manufacturing technique’s quality.
Thermal Over-stress
Since battery cells need to work with a specific temperature capacity, if it is lower than required, unwanted plating happens.
Monitoring Battery Cell
Along with Cell Management Controller, the cell temperature and capacity are determined. It tackles cell characteristics as well as their surrounding. Moreover, the CMB is effective to:
- Examines the cells’ safe operation and tells if they’re over the limit
- Calculates SoC cell voltage capacity
- Describes the accurate cell temperatures, suitable for pack thermal system
Quality Grades of Batteries
Grade A. These cells have the highest standard of quality. They come with an accurate technical specification range, perfect appearance, and no abnormalities or swelling.
Grade B. Grade B has about 80% to 90% effectiveness. It has dissimilarities from grade A, including energy storage, materials, charge, and recharge elements. This cell has a defective rate that may cause charging and discharging consistency.
Grade C. These cells have under average compared to grades A and B. They have immense differences in terms of charging stability, materials, recharging, and energy storage.
Over eight months of storing and unused Grade B will become Grade C. That means, Grade C is formed because of the lengthy storing time and moisture aging.
Repairing Cars’ Batteries
In repairing a car’s battery cell, various tools are needed. That includes,
- Big screwdriver
- Torch
- Battery acid
- Top-up water
- Safety gear
- Anti-acid gloves
- Voltmeter
Here are the important steps:
Step1: Battery Testing Using Voltmeter
A voltmeter is an effective tool for defining the battery’s condition. Just connect the positive part of both the voltmeter and the battery lead. Negative parts also need such steps. Then, you can now determine the battery’s state.
Step2: Battery Cleaning
Get rid of unwanted dirt and oil. There may be many contaminants above the batteries. You can use a dry cloth. Wipe gently the specific vent cap location. Using the screwdriver, unscrew cell caps and keep them in a secure area.
Step3: Examining Electrolyte Fluids
By using the torch, you can examine the electrolyte cell fluid amount. You can define if cells are weak. Then, top-up all cells that require more water and fix up vent caps. Examining again the cell battery condition after twelve hours is advised.
Not-operating batteries need to have well-ventilated spaces.
Step 4: Checking Cell’s Gravity
The cell’s electrolyte gravity also needs to be checked using a hydrometer and combined with limited battery acid. The standard gravity of a battery is 1.265. All the cells must be equal.
Step 5: Recharging and Testing
The battery cells also required recharging and testing. If there is a tendency for sulfation issues that need to be replaced, you can consult expert mechanics.
Recycling Lithium-Ion Battery
The number of used batteries increases constantly. Even though batteries are now created using advanced tech, especially lithium-ion batteries. They are still a treat in many respects. These could bring major environmental problems, health risks, and contamination.
It is fortunate to live in a time where recycling lithium-ion batteries is legal and supported by programs. These will help avoid additional issues brought on by improper battery sorting. And the details below can assist in better understanding how recycling works.
Pyrometallurgy is one of the complex processes of recycling lithium-ion batteries. It’s the process where the battery’s components will be smelted at a high-degree temperature. This procedure separates the mixed metals.
And the other is called hydrometallurgy. This procedure uses cathode material and a basic solution to extract certain metals.
After these processes, the materials will be directly recycled, which will be reused after conditioning.
Battery Cell Testing Procedures
Test Conditions
This process has to be specified among all testing conducted for the battery. There is more than just condition testing, repetition, and comparison made. That includes testing for temperature ranges, cycles, and other factors needed.
Qualification Testing
The qualification procedure includes determining if the battery was precisely built as it was intended. This process also involves if it works properly before proceeding with actual testing on applications. To understand what sub-tests there are here listed below.
- Mechanical. For dimensional and dynamic accuracy
- Environmental. To ensure they endured all conditions
- Abuse. Verifying they are safe for users
- Safety Standards. To show they adhere to all required regulations
- Cycle. Determining the said cycle lifespan
- Load. It is used to specify the battery power
- DEF. To guarantee they are ideal for military application
Production Testing
The leading role of this testing is to ensure that battery’s specs are followed as demand. This test is 100% secured throughout the procedures. It uses representative samples that materials elements should notice. Other than that, it has sub test includes such as
- Charge conditioning.
It’s where the cells are tested to ensure they deliver the correct current.
Performance Monitoring
This test determines whether battery cells operate as expected for the intended use. These consist of user-specified tests.
- DC Measurements. Use for measuring resistance.
- State Of Charge. This test determines the ability of the battery current supply.
- Internal Resistance. It enables the calculation of internal resistance by I2R losses
- SOC Test. Analyzes the remaining energy in a battery.
Battery Tester
These analyzers are developed with the feature of fast rapid indicators. It has a dual function, yet this equipment has no standard format. Every battery producer has a specific arrangement. They have them for defining, measuring, and other conductance parameters.
Failure Analysis
They are also known as cell failure analysis. The manufacturers usually carry out this analysis. It does a cell chemical and chemical components. There are only detailed specifications for this, requiring a high-priced analytical setup.
Understanding Battery Packs, Cells, and Modules
In understanding the field of batteries, more things are needed to learn. For example, batteries that we all know are the general ones. They are used in many small devices, such as remotes, radios, cameras, etc.
However, there are also battery packs, modules, and cells. To understand these phases of battery, learning what they are is needed first. Let’s discuss them step-by-step.
A battery cell is the smallest unit that stores electric energy. The cell must have a high level of energy density to enable such electric storage. That way, it can support any required function for their use.
Also, they have a significant role. As a cell that composes the battery structure, one inflicted damaged cell can sabotage the pack.
The module comes next as another battery phase. Module happens when multiple cells are enclosed in one frame, connected by unifying boundaries. They are accessible in the market.
And the last is a battery pack. The pack is in which the modules, capsulated with several cells, are managed by a battery management system. That also includes the thermal system unified together.
Battery Cells are Made Up of What?
Button cell batteries are manufactured using steel materials, like aluminum, copper black, etc. They come with various elements, including the following
- Potassium
- Nickel
- Iron
- Graphite
- Manganese
- Zinc
- Plastic and paper (extra elements)
How Many Cells are in a Battery?
Various batteries come with one or more cells. These cells form chemical impacts and allow electron circulation in a circuit.
What is the Standard Price of Battery Cells?
Here are standard prices according to battery cell capacity.
Note: The exact prices are always will depend on the companies or manufacturers.
| Capacity | Price (USD) |
| 32V 86AH | $45.87/ piece |
| 3.7V 2600 MAh | $0.66/ piece |
| 3.7V 60AH | $25.35/ piece |
| 3.2V 100AH | $58.40/ piece |
| 3.2V 3200mAh | $0.025/ piece |