The company that first introduced a new type of battery to the world was Sony. But progress did not stand still, and different types of lithium batteries soon appeared. They vary in size, enclosure, capacity, operating and maximum amperage, voltage, discharge and overcharge, explosion hazards, and the consequences of chemical reactions and vapors that can harm the human body. Among all species, one that has begun to stand out today is the lithium iron phosphate (lifepo4) battery. About it, the future will be the latest generation with the most usage, and a competitor to all other lithium-ion analogs.
Lithium iron oxide (LiFePO4, LiFe, LFP, IFR) was discovered by John Goodenough in 1996 as a cathode for lithium-ion batteries. It is significantly different from conventional lithium cobaltate, being less toxic and more heat resistant. But at the same time it also has an obvious disadvantage - the small charging capacity. So at that time the technology was not developed nor attracted anyone until 2003 when the company A 123 Systems became interested in it, under the leadership of Prof. Jiang Yeming, he worked on the manufacture of batteries capable of self-contained under certain conditions Replicate the structure of the colloidal solution. But all research came to a standstill, and a laboratory team led by the professor took on John Goodenough's development and continued to investigate further.
How battery energy storage works
They have a similar structure to other lithium batteries:
Negatively charged electrode (anode) - is made on the basis of copper foil covered with a layer of graphite.
Positively charged element (cathode) - consists of aluminum foil and a layer of lithium iron phosphate.
Electrolyte - Designed to fill the space between the cathode and anode, allowing positive lithium ions to pass through, but not negatively charged electrons. Typically, liquid electrolytes are based on lithium salts.
A separator or separator is a porous polyethylene sheet that absorbs and retains the electrolyte well and also separates the cathode from the anode. Avoid irreversible chemical reactions in the event of plate shorts or the growth of formed lithium metal dendrites.
The main difference from lithium-ion batteries is the lithium iron phosphate positive electrode. The battery has a roll-up device consisting of 3 strips: the anode, electrolyte separator, and cathode, twisted into layers. All copper and aluminum layers are each connected to form a single contact with positive on the top and negative on the bottom. When the battery begins to discharge due to a load, lithium ions flow from the positive electrode to the negative electrode through the separator, releasing the accumulated charge and triggering an oxidation reaction. When charging, lithium ions pass through the separator from anode to cathode and accumulate charge while undergoing a recovery process.
Types and Forms of Lithium Metal Phosphate Batteries
Depending on the shape of the housing and the location of the contacts, they are divided into 4 types:
square battery
Encapsulated in a closed aluminum housing with top contacts and pressure relief valve. They can contain two or more parts internally in the form of a package.
flat battery
It's like a bag. They have a compact and flat shape with a thin aluminum shell that is easily damaged and an upper arrangement of contacts.
Cylindrical battery
Cylindrical cells are cells with contacts on the top (positive) and bottom (negative).
Unlike the usual AA and AAA notations, cylindrical batteries have their own standard size or form factor, where the first 2 digits indicate the diameter and the following numbers indicate their height. In some variants, the number 5 is placed last, indicating that the battery height corresponds to half a millimeter. The most common form factors are 14430, 14505, 15335, 18500, 18650, 22650, 26650, 32600, 32650, 32700, 32900, 38120, 40160, 42120, 46160.
For cylindrical batteries, the marking consists of linear dimensions (width, length, height), for example, the standard size 27148205 is 27 × 148 × 205.
Modular battery
Appearance is similar to a normal car battery, or in the form of a plastic case with a handle and indicator panel. They contain prismatic devices or batteries with parallel or series connections, depending on the voltage and current required, and BMS protection boards with built-in voltage balancers or as add-on boards for charge-discharge regulation and short-circuit protection alone. each element separately. It can be equipped with an LCD panel, power-on and charging indicators, and can also be made into a waterproof and shock-proof casing.
Lithium-ion battery application and use precautions
These batteries are ideal for use in personal electric vehicles such as: e-scooters, e-bikes, ATVs, scooters, mopeds, motorcycles, electric vehicles. They can be used year-round in varying temperatures and other conditions. Also used in: boats with electric motors, forklifts, wheelchairs, vacuum cleaners, floor cleaners. But they are mostly used in power generation systems, such as wind and solar power, which are part of battery power plants, as well as emergency and autonomous power supply systems for hospitals, banks, weather stations and cellular stations.
