The application of green lithium iron phosphate battery in mobile base station

Lithium iron phosphate battery refers to a lithium ion battery that uses lithium iron phosphate as a positive electrode material. There are many kinds of cathode materials for lithium-ion batteries, mainly lithium cobaltate, lithium manganate, lithium nickelate, ternary materials, lithium iron phosphate, etc. Among them, lithium cobalt oxide is the cathode material used in the vast majority of lithium-ion batteries at present, while other cathode materials have not been mass-produced in the market due to various reasons. Lithium iron phosphate is also one of the lithium-ion batteries. In terms of material principle, lithium iron phosphate is also an intercalation/deintercalation process, which is exactly the same as lithium cobaltate and lithium manganate.

The battery does not contain any heavy metals and rare metals (nickel-metal hydride batteries require rare metals), non-toxic (SGS certification), non-polluting, in line with European RoHS regulations, and is an absolute green battery certificate. There is a large amount of lead in lead-acid batteries. If they are disposed of improperly, they will still cause secondary pollution to the environment, and lithium iron phosphate materials are non-polluting in production and use. It has entered the 863 national high-tech development plan during the tenth five-year period, and has become a key project supported and encouraged by the state. With China’s entry into the WTO, the export volume of China’s electric bicycles will increase rapidly, and now electric bicycles entering Europe and the United States have been required to be equipped with non-polluting batteries.

Lithium iron phosphate batteries also have their shortcomings: for example, the tap density of lithium iron phosphate cathode materials is small, and the volume of lithium iron phosphate batteries of equal capacity is larger than that of lithium ion batteries such as lithium cobalt oxide, so it has no advantages in micro batteries.

The bottleneck of valve-regulated sealed lead-acid battery is gradually emerging

The performance of lithium-ion power batteries mainly depends on the positive and negative electrode materials. Lithium iron phosphate as a lithium battery material has only appeared in recent years. The large-capacity lithium iron phosphate battery was developed in July 2005. Its safety performance and cycle life are unmatched by other materials, and these are the most important technical indicators of power batteries. 1C charge and discharge cycle life up to 2000 times. Single-cell battery overcharge voltage 30V will not burn, puncture will not explode. The lithium iron phosphate cathode material makes large-capacity lithium-ion batteries easier to use in series. At present, VRLA batteries have become the preferred battery for communication power systems due to their small size, stable voltage, no pollution, light weight, high discharge performance, and low maintenance. However, in actual use, there are many cases where the theoretical life expectancy is not reached. Theoretically, batteries that work for 7 to 10 years are mostly damaged within 2 to 3 years, and some cannot even reach a life span of 1 year, resulting in great economic losses.

In addition, due to the relatively lagging power development in my country, the national power shortage is relatively serious. Many areas have experienced insufficient power and power shortage. Power cuts also occur from time to time. Mobile base stations are all over urban and rural areas, and the supply of mains power is insufficient. Objectively speaking, the use and maintenance of valve-regulated sealed lead-acid batteries in base stations is a great test. If the maintenance is not timely, it will directly affect the performance and service life of valve-regulated sealed lead-acid batteries.

Four advantages of Haiba lithium iron phosphate battery

Haiba lithium iron phosphate battery is a lithium ion battery produced by Haiba Group with lithium iron phosphate as the positive electrode material. Compared with lead-acid batteries, lithium iron phosphate battery has the advantages of light weight, high and low temperature resistance, long life, safety, environmental protection and no pollution, etc.

1. Ambient temperature

Excessive ambient temperature has a great impact on the service life of VRLA batteries. When the temperature rises, the corrosion of the battery plates will intensify, and more water will be consumed at the same time, thereby shortening the battery life. The battery can obtain a long life in the environment of 25 ℃. If the long-term operating temperature is increased by 10 ℃, the service life will be reduced by about half. In addition, when the ambient temperature is 25 ℃ ~ 0 ℃, the discharge capacity will lose about 1% for every 1 degree decrease, so the battery should work in the environment of 15 ℃ ~ 20 ℃.

The operating environment temperature of Haiba lithium iron phosphate battery is -20°C to 70°C. In the cold winter season, the indoor temperature of the base station can be as low as -15°C, and in the hot season, the indoor temperature of the base station can reach 50°C. Ba lithium iron phosphate batteries have good performance. The impact of ambient temperature on Haiba lithium iron phosphate batteries is far less than that on lead-acid batteries.

2. Overcharge and overdischarge

When the lead-acid battery is overcharged, the positive electrode is consumed due to the oxygen evolution reaction, and the H+ increases, resulting in an increase in the acidity near the positive electrode, which makes the grid thinner, accelerates the corrosion of the battery, and reduces the battery capacity. There is a danger that the battery will dry up, thereby affecting the life of the battery.

The over-discharge of lead-acid batteries mainly occurs after the AC power supply is cut off, and the battery supplies power to the load for a long time. Because lead sulfate is an insulator, its formation will have a great negative impact on the charging and discharging performance of the battery. Therefore, the more sulfates formed on the cathode, the greater the internal resistance of the battery, and the charging and discharging of the battery. The worse the performance, the shorter the battery life.

The battery pack is equipped with a battery management system. The battery management system can monitor the voltage of each single cell in the battery pack and the total voltage of the battery pack. During the charging and discharging process, the total voltage reaches the set value or the single cell voltage. When the set value is reached, the management system can terminate the charge and discharge in time, so that the battery pack will not be overcharged and overdischarged.

3. Long-term floating charge

The floating charging current provided by the switching power supply of the DC system has three functions for the valve-regulated battery: supplying the daily load current, supplementing the loss of self-discharge of the battery, and maintaining the oxygen cycle in the battery. If the battery is only charged but not discharged in the long-term floating charge state, the anode plate of the battery will be passivated, the internal resistance of the battery will increase, the capacity will be greatly reduced, and the service life of the battery will be shortened. In addition, the selection of lead-acid battery float voltage should be adjusted according to the state of the battery. Inappropriate float voltage may cause overcharge, affect the service life of the battery, or cause the battery to be undercharged for a long time.

The self-discharge rate of Haiba lithium iron phosphate battery is very low, and the capacity retention rate can be 98% after 30 days of shelving. Therefore, the battery pack is in a floating state for a long time. The floating current provided by the switching power supply is almost all used for daily load current. The current to supplement the self-discharge loss of the battery pack is very small. In addition, the lithium iron phosphate battery is not sensitive to the choice of the floating charging voltage, and it is resistant to floating charging, which is more suitable for the backup power supply of the base station.

4. Cost of use

The cost of using a battery pack for a communication base station needs to comprehensively consider the cost of the battery, the service life of the battery, and the maintenance cost during use.

The price of lead-acid batteries is low, but due to the short service life, most of the batteries that work for 7 to 10 years are damaged within 2 to 3 years, and some cannot even reach 1 year of life. In addition, during the use process It requires manual inspection and maintenance, and the use cost is very high.

Haiba lithium iron phosphate battery has performances such as maintenance-free and long service life. The fully intelligent battery management system replaces the manual detection process. The automatic detection and protection performance of the battery management system reduces the failure rate of the battery pack to the limit. , The ultra-long design service life greatly reduces the use cost of the communication industry.