With the worldwide emphasis on renewable energy sources such as solar and wind, energy storage has become an essential solution for grid stability and reliability. Not only that, but energy storage is also an important research direction in the field of electric vehicles. So let’s learn more about energy storage and energy storage battery today.

Classification of energy storage

Energy storage is storing energy through a medium or device and releasing it when needed. According to the energy storage method, energy storage can be divided into three categories: physical energy storage, chemical energy storage, and electromagnetic energy storage, of which physical energy storage mainly includes pumped storage, compressed air energy storage, flywheel energy storage, etc. Chemical energy storage mainly includes lead-acid batteries, nickel batteries, lithium batteries, liquid flow batteries, and sodium-sulfur batteries, and electromagnetic energy storage mainly includes supercapacitor energy storage and superconducting energy storage.

energy storage batteries

What is a battery?

A battery is a device for energy conversion and storage, which converts chemical or physical energy into electrical energy through a reaction. Batteries can be divided into chemical and biological batteries according to the difference in energy conversion.

A chemical battery or chemical power supply is a device that converts chemical energy into electrical energy. It consists of two electrochemically active electrodes of different compositions as positive and negative electrodes, respectively, and a chemical substance that provides media conduction as an electrolyte, which provides electrical energy by converting its internal chemical energy when attached to some external carrier. A physical battery is a device that converts physical energy into electrical energy.

Lead-acid battery: It is a kind of battery whose electrode is mainly made of lead and its oxide and whose electrolyte is a sulfuric acid solution. In the discharged state of a lead-acid battery, 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 positive and negative electrodes is lead sulfate. The advantages of lead-acid batteries are mainly: safety sealing, gas discharge system, simple maintenance, long service life, stable quality, and high reliability; the disadvantage is that the pollution of lead is significant, and the energy density is low (that is, too bulky).

Nickel-based battery: NiMH battery is a kind of battery with good performance. The positive active substance of NiMH battery is Ni(OH)2 (called NiO electrode), the damaging active substance is metal hydride, also called hydrogen storage alloy (called hydrogen storage electrode), and the electrolyte is a six mol/L potassium hydroxide solution. The advantages of nickel-based batteries are: high energy density, fast charging and discharging, lightweight, long life, and no environmental pollution; the disadvantages are a slight memory effect, more management problems, and accessibility from a single battery compartment melting.

Lithium-based batteries: Lithium-ion batteries, a class of batteries with lithium metal or lithium alloy as the anode material and using a non-aqueous electrolyte solution, have very high environmental requirements due to the very active chemical properties of lithium metal, which makes the processing, preservation, and use of lithium metal. With the development of science and technology, lithium-ion batteries have become mainstream.

Its significant advantages are: long service life, high storage energy density, lightweight, and adaptability; disadvantages are poor safety, ease of exploding, high cost, and limited use conditions are restricted.

Liquid flow battery: liquid flow energy storage battery is a class of devices suitable for stationary large-scale energy storage (storage); compared to the currently used lead-acid batteries, nickel-cadmium batteries, and other secondary batteries, with power and storage capacity, it can be independently designed (energy storage medium stored outside the battery), high efficiency, long life, can be deeply discharged, environmentally friendly and other advantages, is one of the preferred technologies for large-scale energy storage technology. The benefits of liquid flow batteries are a flexible layout, long cycle life, fast response times, and no harmful emissions; the disadvantage is that the energy density varies greatly.

Sodium-sulfur battery: Sodium-sulfur battery is a secondary battery with sodium metal as the negative electrode, sulfur as the positive electrode, and ceramic tube as the electrolyte diaphragm. At a certain working degree, sodium ions pass through the reversible reaction between the electrolyte diaphragm and sulfur to form the release and storage of energy. Sodium-ion battery advantages and disadvantages: specific point up to 760Wh/kg, no self-discharge phenomenon, discharge efficiency of almost 100%, and life can reach 10 to 15 years; the disadvantage is high-temperature 350ºC melting sulfur and sodium.

Ternary polymer lithium battery: The ternary lithium-ion battery refers to a lithium battery using the ternary cathode material of nickel cobalt manganate (Li(NiCoMn)O2) or nickel cobalt lithium aluminate as the cathode material. The ternary composite cathode material is nickel salt and cobalt salt. The manganese salt is used as the raw material, and the proportion of nickel, cobalt, and manganese can be adjusted according to actual needs. The advantage of ternary lithium-ion batteries is high energy density and good cycle performance, and the disadvantage is poor safety in high temperatures.

Lithium iron phosphate battery: refers to the lithium-ion battery using lithium iron phosphate as the cathode material. This type of battery is characterized by the absence of precious metal elements (such as cobalt, etc.). In actual use, lithium iron phosphate batteries have the advantages of high-temperature resistance, strong safety stability, and better cycle performance. The disadvantage is the lower energy and higher manufacturing costs.

SETEC POWER’s Emergency mobile EV charging system is a lithium iron phosphate battery. Combining energy storage and fast charging technology enables charging station operators to differentiate their services. It also uses lithium iron phosphate batteries with long service life, no maintenance, extreme safety, lightweight, and improved discharge and charging efficiency. LiFePO4 batteries are not the cheapest in the market, but due to their long life span and zero maintenance, it’s the best investment you can make over time.