1. Lead-acid batteries
A lead-acid battery is a type of rechargeable battery whose electrodes are primarily made of lead and its oxides, and whose electrolyte is a sulfuric acid solution. In the discharged state, the main component of the positive electrode is lead dioxide, and the main component of the negative electrode is lead; in the charged state, the main component of both the positive and negative electrodes is lead sulfate.
Lead-acid batteries have the following advantages: safe and sealed, venting system, simple maintenance, long service life, stable quality, and high reliability; the disadvantages are that they cause significant lead pollution and have low energy density (meaning they are too bulky).
2. Nickel-based batteries
Nickel-metal hydride (NiMH) batteries are a type of high-performance rechargeable battery. The positive electrode active material is Ni(OH)₂ (called the NiO electrode), the negative electrode active material is a metal hydride, also known as a hydrogen storage alloy (the electrode is called the hydrogen storage electrode), and the electrolyte is a 6 mol/L potassium hydroxide solution.
Nickel-metal hydride batteries have the following advantages: high energy density, fast charging and discharging speed, light weight, long life, and no environmental pollution; their disadvantages include slight memory effect, more management issues, and a tendency for the separator of individual cells to melt.
3. Lithium-ion batteries
Lithium-ion batteries are a type of battery that uses lithium metal or lithium alloys as the negative electrode material and a non-aqueous electrolyte solution. Due to the highly reactive chemical properties of lithium metal, its processing, storage, and use require very strict environmental control. With the development of science and technology, lithium-ion batteries have now become the mainstream.
The advantages of lithium-ion batteries include: long lifespan, high energy density, light weight, and strong adaptability; the disadvantages include poor safety, easy explosion, high cost, and limited usage conditions.
4. Flow battery
Flow batteries are a type of device suitable for large-scale stationary energy storage. Compared with commonly used secondary batteries such as lead-acid batteries and nickel-cadmium batteries, they have advantages such as independent design of power and energy storage capacity (energy storage medium is stored outside the battery), high efficiency, long life, deep discharge capability, and environmental friendliness, making them one of the preferred technologies for large-scale energy storage.
The advantages of flow batteries include: flexible layout, long cycle life, fast response, and no harmful emissions; the disadvantage is that the energy density varies greatly.
5. Sodium-sulfur batteries
A sodium-sulfur battery is a secondary battery that uses metallic sodium as the negative electrode, sulfur as the positive electrode, and a ceramic tube as the electrolyte membrane. Under certain operating conditions, sodium ions undergo a reversible reaction with sulfur through the electrolyte membrane, resulting in the release and storage of energy.
The advantages of sodium-sulfur batteries include: high specific energy of up to 760Wh/kg, no self-discharge, discharge efficiency of almost 100%, and lifespan of 10 to 15 years; the disadvantage is that sulfur and sodium melt at a high temperature of 350℃.
