What are the Common Types of Storage Batteries

What are the Common Types of Storage Batteries?

A storage battery, also known as a rechargeable battery, is a device capable of storing chemical energy and converting it into electrical energy when needed. It is widely used in various fields such as household appliances, power systems, and transportation vehicles. Currently, several types of storage batteries have achieved large-scale commercial application. The most common ones are lead-acid batteries, nickel-cadmium (Ni-Cd) batteries, nickel-metal hydride (Ni-MH) batteries, and lithium-ion (Li-ion) batteries.

Lead-Acid Batteries

Lead-acid batteries are the most widely used type of storage battery, commonly found in applications like automotive starting, lighting, and ignition (SLI) and uninterruptible power supplies (UPS). Their basic structure uses lead and its oxides as the active electrode materials and a sulfuric acid solution as the electrolyte. In a discharged state, the positive plate is primarily lead dioxide (PbO2), and the negative plate is lead (Pb). During charging, lead sulfate (PbSO4) forms on the surfaces of both plates. Despite advantages such as low cost, high reliability, and mature technology, lead-acid batteries suffer from drawbacks like relatively low energy density, limited cycle life, and significant weight, which constrain their use in certain high-performance or portable applications.

Advantages

Low Cost: The manufacturing process for lead-acid batteries is relatively simple, resulting in low production costs and, consequently, a low market price. High Reliability: The design and materials used in lead-acid batteries are stable and reliable, providing tolerance to a certain degree of over-discharge and overcharge.

Disadvantages

Low Power Density: Lead-acid batteries have a relatively low power density, which limits their output power capability. Short Lifespan: The service life of lead-acid batteries is relatively short, typically around 2 to 3 years. Heavy Weight: Compared to other battery types, lead-acid batteries of equivalent capacity are bulkier and heavier.

Lithium-Ion Batteries

Lithium-ion batteries are one of the mainstream high-performance batteries on the market today, extensively used in mobile electronic devices, power tools, and electric vehicles. They employ carbon materials capable of intercalating lithium ions (e.g., petroleum coke, graphite) as the negative electrode, replacing the metallic lithium or lithium alloy anodes used in traditional lithium batteries. This design significantly improves safety and cycle life. The positive electrode typically uses lithium cobalt oxide (LiCoO2), although materials like lithium nickel oxide (LiNiO2) or lithium manganese oxide (LiMn2O4) are also used. The electrolyte is usually an organic carbonate solution containing LiPF6, with solvents such as ethylene carbonate (EC) and dimethyl carbonate (DMC). Based on the state of the electrolyte, lithium-ion batteries are primarily categorized into two types: liquid lithium-ion batteries (LiB) and polymer lithium-ion batteries (PLB).

Advantages

High Power Density: Lithium-ion batteries offer high power density, superior to that of lead-acid and nickel-cadmium batteries. Long Cycle Life: They have a long service life, capable of thousands of charge-discharge cycles. Lightweight: Lithium-ion batteries are lighter compared to lead-acid and nickel-cadmium batteries.

Disadvantages

Risk of Fire and Explosion: Lithium-ion batteries have relatively poor stability. Improper charging or usage can lead to issues like leakage, short circuits, and safety hazards including fire and explosion. High Cost: The materials used inside lithium-ion batteries are more expensive, resulting in higher manufacturing costs.

Nickel-Cadmium (Ni-Cd) Batteries

Nickel-cadmium batteries are a type of alkaline battery where the positive active material is nickel oxyhydroxide, the negative active material is cadmium, and the electrolyte is a potassium hydroxide (KOH) solution. The positive electrode uses nickel hydroxide, the negative electrode is metallic cadmium, and the electrolyte is typically a potassium hydroxide solution.

This battery type offers advantages such as high power density, long cycle life, robust construction, and good resistance to shock. It is commonly used in small electronic devices and applications requiring high reliability. Compared to lead-acid batteries, nickel-cadmium batteries perform better in terms of power density and cycle life, leading to their widespread use in military, aerospace, and industrial fields.

Advantages

High Power Density: Ni-Cd batteries have a higher power density than lead-acid batteries, enabling higher output power. Long Cycle Life: They have a long operational life, typically capable of over two thousand charge-discharge cycles. High-Temperature Tolerance: Ni-Cd batteries can withstand high temperatures, operating normally within a range of -20°C to 65°C.

Disadvantages

High Material Cost: The use of high-purity nickel and cadmium makes manufacturing costs relatively high. Toxicity: Due to the toxicity of cadmium, nickel-cadmium batteries are classified as hazardous waste, requiring special handling and recycling procedures.

Nickel-Metal Hydride (Ni-MH) Batteries

Nickel-metal hydride batteries are a type of rechargeable battery that uses nickel oxyhydroxide for the positive electrode, a hydrogen-absorbing alloy for the negative electrode, and an alkaline solution as the electrolyte. They offer good overall performance. The positive active material is Ni(OH)2 (also called NiO electrode), while the negative electrode employs a metal hydride (hydrogen storage alloy) capable of reversible hydrogen absorption/desorption. The electrolyte is typically a 6 mol/L potassium hydroxide solution. Based on operating pressure, they are categorized into high-pressure and low-pressure types. Compared to lead-acid batteries, Ni-MH batteries provide higher power density, longer service life, a lighter and more compact structure, and environmental friendliness. They are primarily used in consumer electronics and related fields today.

Advantages

High Power Density: Ni-MH batteries have a relatively high power density. Environmentally Friendly: They do not contain highly toxic substances, posing less environmental harm. Lightweight: Compared to lead-acid batteries, Ni-MH batteries of equivalent capacity are smaller and lighter.

Disadvantages

High Cost: The price of Ni-MH batteries is relatively high due to higher manufacturing costs. High Self-Discharge: When not in use, they exhibit a relatively fast self-discharge rate, requiring regular charging to maintain optimal performance.