Lithium batteries are divided into two categories: lithium metal batteries and lithium-ion batteries. The latter does not contain lithium in the metallic state and is rechargeable. Lithium-ion batteries, due to its high technological complexity, are currently only able to be produced by companies in a few countries. The most widely used lithium batteries in the market are lithium-ion batteries.
The working principle of lithium iron phosphate battery:
A lithium iron phosphate battery, or LiFePO4 battery, is a type of lithium-ion battery using lithium iron phosphate as a positive electrode material. The negative electrode is composed of graphite, and the diaphragm between the electrodes is made of PP/PE/PP (PE: polyethylene, PP: polypropylene). The electrolyte can be doped with various substances, such as Tributyl phosphate (TBP).
During the charging process of the lithium iron phosphate (LiFePO4) battery, lithium ions are continuously extracted from the positive electrode and then moved to the negative electrode; when power output reaches saturation, almost all the lithium ions have been embedded in the negative electrode, forming an overcharge protection voltage; this results in a safety mechanism for the battery and makes it more stable.
Excellent heat resistance and thermal stability:
Even if the external temperature reaches 65 degrees Celsius and the internal temperature reaches 94 degrees Celsius, the lithium iron phosphate battery remains safe and will not ignite. Even if there is external or internal damage. In contrast, ternary lithium batteries can ignite or explode if overheated, making them less safe than lithium iron phosphate batteries.
Excellent performance in terms of cycle life and experience.
Even after 3000 cycles, lithium iron batteries can still retain 80% of their capacity. lower overall costs. Conventional nickel batteries suffer from memory effect (incomplete charging and discharging for a long time leaves traces on the battery, reducing battery capacity) and phosphoric acid. Lithium iron batteries do not need to be discharged before charging.
Portable and mobile
Lithium iron phosphate batteries are currently used in commercial and industrial solar systems and electric vehicles. They can greatly reduce weight and improve endurance and mileage. From the characteristics of lithium iron phosphate, we can easily find that its performance is extremely suitable for power applications, and it is widely used in the electric vehicle industry. The core power source of a lithium iron phosphate material can ensure unparalleled safety while providing stable and efficient output.
Disadvantages and Future of Lithium Iron Phosphate Batteries
Everything has two sides. Due to factors such as particle size and electrolyte raw materials, high-temperature performance is good, but the performance of lithium iron phosphate batteries is poor at low temperatures. This situation is more pronounced below 0 degrees Celsius, which is very important. To some extent, performance is limited in high latitude and high altitude regions. Lithium iron phosphate also has low tapped and compacted densities, resulting in low energy densities. This problem seems to be solved by nanometerization and carbon coating. However, with the injection of more fresh energy, lithium iron phosphate batteries have good development prospects in the increasingly hot new energy field.
Environmental and Recycling Issues
The issue of battery recycling and environmental protection has become a major concern for the development of environmentally friendly technology. Traditional batteries cause serious environmental pollution due to low social awareness of recycling and no specific measures taken. However, lithium iron phosphate batteries do not contain polluting heavy or rare metals, are certified non-toxic and non-toxic by SGS, and comply with European ROHS regulations.
Lithium iron phosphate batteries are produced and used environmentally friendly. The recovery of lithium iron phosphate batteries depends on the performance of the anode graphite, which degrades faster than the cathode material LiFePO4. Research on the recovery of graphite as a cathode material is limited because graphite is relatively low in price, and relatively small in quantity, and recycling may not be ideal.
Chemical precipitation is a process for recycling used batteries. The most economically valuable Li and Fe are recovered and recycled as chemical raw materials, and high-temperature solid-phase repair/regeneration technology and leaching technology using Thiobacillus ferrooxidans are also attracting attention in research.
The application of the lamination process in lithium iron phosphate batteries
The advancement of automation control methods has led to an increase in the usage of high-density lamination in the production of zero lithium iron phosphate batteries. This trend, however, causes problems for battery producers. After switching from winding to lamination, overlapping pole pieces often enter the processing link, which causes the entire lithium battery cell to be scrapped and increases operating costs.