Lithium-ion batteries are some of the most commonly used batteries to power millions of people each day. These batteries are growing in popularity because of their lightweight, high energy density, and ability to recharge. Battery technology is constantly advancing, but the core functionality of the battery remains unchanged.

For years, batteries have been essential to devices for storing energy in chemical reactions and releasing it as electricity. These types of batteries are used in laptops, cell phones, hybrids, and electric cars. The complex circuitry of smartphones also relies on these batteries.

What Should We Do When Our Smartphone Battery Is Damaged or Dies?

Batteries are the most critical component of our devices, but we don’tneed to learn much about them. Most smartphone manufacturers use a Li-ion battery containing a tiny pack of volatile chemicals and metals separated by a super-thin non-conductive layer. Inside are positive electrodes made up of lithium cobalt oxide and negative electrodes made up of carbon, both of which are kept inside an electrolyte solution.

Whenever you plug in your device to charge your smartphone, the lithium ions are attracted towards positive electrodes through the electrode solution, allowing the battery to store energy for later use. A circuit controls these to regulate the right amount of voltage, which helps prevent overcharging and overheating. Temperature also affects batteries; batteries start to be exposed after 37°C.

Keep in mind that you cannot keep recharging a single battery forever. You have to replace the battery. Every battery has a lifespan. Ensure you do not throw your batteries in the garbage because it affects the environment. Not to mention, batteries are incredibly toxic and flammable.

If your battery is in good condition and shape, send it to your local waste management company or battery recycler. Alongside, if your battery is not in good condition or is swollen due to physical damage, a malfunctioning potential circuit, or overcharging, you should prevent it before it harms anyone. Just fill a bucket with saltwater and drop your batteries in it for a couple of days, which helps discharge the battery.

What is a Battery?

A battery comprises super-tightly packed, highly volatile chemicals and metals, separated by super-thin, non-conductive layers that prevent the electrodes from touching and triggering potentially explosive thermal reactions. This separator prevents them from reacting with each other, except when you crack a Li-ion battery.

Batteries are small containers of chemical energy plugged into electricity to reset a chemical reaction within the battery, transferring from the negative anode to the cathode (the positive end of the battery). Battery life does not stay constant for the entire life of a device; it diminishes slowly over time as the battery is discharged and recharged. The higher the resistance, the more complex the battery has to work to maintain a usable voltage, so the amount of power it can produce per charge decreases.

  • Voltage = Current X Resistance (V = IR)

How Does a Lithium-Ion Battery Work?

A battery comprises an anode, cathode, separator, electrolyte, and two current collectors (positive and negative).

  • The anode and cathode store lithium.
  • The electrolyte carries positive-charge lithium ions from the anode to the cathode (and vice versa) through the separator.
  • The electrolyte is a liquid conductor between the cathode and anode.
  • The separator is used to block the flow of electrons inside the battery.

The lithium-ion movement creates a free electron in the anode, which helps create a charge at the positive current collector. With the electrical current flowing through the powered device (cell phone, computer, etc.), the current collector flows to the negative current collector.

When the battery is charged, electric energy flows into the battery, causing lithium ions to move from the anode to the cathode. This creates a positive charge on the cathode and a negative charge on the anode. Once the battery is fully charged, the lithium ions remain on the cathode and are ready to release electricity when the battery is used.

Key Factors to Determine the Performance of Lithium-Ion Batteries

  • Capacity: How much energy it can store, typically measured in milliampere-hours (mAh) or ampere-hours (Ah).
  • Voltage: Measures the electrical potential stored within the battery, typically ranging from 3.7 to 4.2 volts.
  • Energy density is the amount of energy stored in a given volume, determining the overall performance and suitability for a specific application.
  • Self-Discharge Rate: The rate at which the battery discharges when not in use. It can vary among different types of lithium-ion batteries. The number of cycles it can undergo before reaching the end of its useful life is called its cycle life.
  • Operating Temperature: It is an essential factor in determining its performance. High temperatures can cause the electrolyte to break down, reducing battery capacity and shortening its lifespan. Lower temperatures can make the electrolyte more viscous, reducing the battery’s ability to charge and discharge quickly.
  • Charging and Discharging Rate: The speed at which the battery can be charged and discharged is typically expressed in current units such as amperes or milliamperes. A higher charging and discharging rate means the battery can be charged or discharged more quickly.
  • Battery Management Systems: Also known as BMS, it is one of the essential components of a lithium-ion battery that helps regulate the battery’s voltage and temperature to ensure optimal performance and safety. A high-quality BMS can extend the overall cycle life of the battery.

Why Do Smartphone Batteries Explode?

Smartphone batteries are typically very safe. However, various factors can cause them to explode, mostly in extreme situations.

  • Due to heat, a short circuit in the circuit, or some other external cause.
  • A chemical reaction inside the hot area begins generating heat that spreads to other areas through electrolyte overheating.
  • Battery overheating causes the electrolyte to give off steam, which then bursts the battery casing.
  • A very flammable, hot liquid escapes and usually burns or melts the surrounding phone, causing whatever phone is next to it to explode. The subsequent heat can start other fires.
  • Dropping and damaging the battery. Check for swelling, deformation, and frequent, unexplainable overheating.
  • Hot temperatures and environments Many elements contribute, like running intensive graphics, which put a heavy load on the CPU, using apps that consume much power on the CPU, and regular connectivity checks when cellular or Wi-Fi connections are spotty.
  • Using the wrong charger.
  • Getting the phone wet
  • Battery punctures.

Charge and Discharge

  • When a battery discharges, it releases electric current.
  • The anode releases lithium ions to the cathode to generate a flow of electrons from one side to another.
  • When the user plugs in the device, lithium ions are released by the cathode and received by the anode.

Energy Density and Power Density

The two most common concepts associated with batteries are energy and power density.

  • Energy density is measured in Watt-hours per Kilogramme (Wh/Kg), which is the amount of energy stored concerning its mass.
  • Power density is measured in watts per Kilogramme (W/Kg), the amount the battery generates concerning its mass.

How to Help Your Battery Last Longer

Inside the Smartphone Battery: How They Work Explained!

The best practice you can do is to keep a lithium-ion battery roughly between 8% and 20% charged, which helps preserve a more significant amount of its capacity for longer. This is because of the nature of the battery, which has to work harder in the last 20% of discharge and above 80% of charging.

Risk of Lithium-Ion Batteries

Lithium-ion batteries are commonly used in smartphones and can be a fire hazard if damaged or defective. If the battery gets punctured or damaged, it can release chemicals that may cause injury if they come into contact with the skin and eyes or are inhaled. Not all modern batteries have safety features to prevent overheating and fire. Most manufacturers have strict quality control and testing standards to minimise the risk of defective batteries. Suppose you notice any unusual behaviour with your device, such as overheating, swelling, or leakage. In that case, stopping using the device and contacting a professional to dispose of the battery properly is essential.

Inside the Smartphone Battery: How They Work Explained!

If your battery swells with gases due to physical damage or malfunctioning protection circuitry resulting in overcharging, it acts as a safety system by containing the outgassing. Temperature is another crucial factor in keeping your Li-ion batteries healthy and happy, as exposure to high temperatures over 100°F through multiple charge cycles will reduce longevity.

Note: Do not keep Li-ion batteries fully discharged for an extended period. The battery protection circuit will cut off the battery when it drains too low. The battery will continue to self-discharge, damaging the battery’s capacity and ability to recharge.

Modern Battery with Smart Circuitry within the Battery

Nowadays, batteries help prevent damage or danger. They have built-in governors that work with other safety systems, so you can keep your already-charged iPhone in overnight without damaging the battery.

In the future, we may see batteries that last for more extended periods. Some examples of future battery technologies include Lithium-Sulphur Batteries, Lithium-Air Batteries, Solid-State Batteries, Sodium-Ion Batteries, Flow Batteries, and Hybrid Batteries. It is difficult to say if this technology could be used in portable devices.

These batteries also have a significant impact on the environment. The damage caused by mining and processing the raw materials used in batteries, such as Lithium, Cobalt, Nickel, and Rare Earth Metals, can cause habitat destruction, water pollution, and human rights violations. Additionally, the chemicals used in the battery production process can be toxic and harmful to the environment if not correctly disposed of.