Lithium iron phosphate battery such as small volume, light weight, high temperature performance is good wait for a characteristic, has gradually replaced traditional lead-acid battery, become a communications industry widely used a new type of battery. Based on a large telecommunication operators, for example, aimed at the difficulty in the lead-acid battery is in use and maintenance, puts forward the lithium iron phosphate batteries in the construction of communication network for different scenarios, and analyzes its advantage in different application scenarios, provide help for the selection of backup battery for communication operators.
In the mobile communication equipment, main power is cut off battery equipment continuous operation is the important component of battery performance will directly affect the communication network safe operation of the enterprise. At present, mobile battery back-up power supply are mostly use valve control type lead acid battery. Valve control type lead acid storage battery with mature technology, stable quality, can be more series-parallel use only, no memory effect, abundant resources, low cost and the recovery rate of lead in battery highest etc, and widely used.
But after nearly 20 years of application, lead-acid battery is gradually exposed some problems: a) discharge cycle life is short. B) the high temperature performance is poor. In 40 ~ 50 ℃ under the environment of high temperature continuous use, easy to drum shell, crack and leakage problems. C) is lower than the energy. Battery weight is heavy, large volume, to take up the space is large. D) charging time is long, can’t quick charge. In the case of frequent power outages, often will again to discharge the battery has not been charged, lead to battery performance rapid attenuation.
At present, the telecommunication operators for valve control type lead acid storage battery maintenance department has a lot of new methods of maintenance and received certain effect, but can’t fundamentally solve the battery in reliability, high temperature resistance, specific energy and charging issues. As a result, the industry has gradually to look to the vigorous development of the lithium iron phosphate battery in recent years.
1 Working principle of lithium iron phosphate battery
1) physical properties
The formulas for the lithium iron phosphate LiFePO4. According to the research achievements of the Texas state university in 1997, LiFePO4 battery in the process of charging, the anode of lithium ion Li + through the polymer membrane to the cathode migration; In the process of discharge, the cathode of lithium ion Li + migration through the diaphragm to the positive. As lithium ion battery cathode material, has excellent electrochemical performance, charge and discharge platform is very smooth, stable structure in the process of charging and discharging. At the same time, the material has non-toxic, no pollution, safety performance is good, can be used in high temperature environment, sources of raw materials, etc, are racing to develop current battery field research hot spot.
2) product form
According to the development of the industry at present, lithium iron phosphate batteries of the nominal voltage of 3.2 V, 16 series can be formed by 48 V battery module. Lithium iron phosphate battery capacity level for commonly used 10 AH, AH, AH, 50 20 150 200 AH AH, AH, AH 300, 200, the main types of batteries have cylindrical, square shape, three types of soft packages. Communications industry used commonly used battery voltage grade 2 V and 12 V dc switching power supply system and supporting the use of 48 V battery voltage grade, communicate with UPS (uninterruptible power supply) power supply system supporting the use level of the battery voltage is 96 V, 240 V, 384 V, etc. Commonly used level of battery capacity is 100 AH, AH, AH, AH 500, 200 150 150 AH, etc.
To meet the needs of the communications industry backup battery energy storage, lithium iron phosphate battery pack module can be through the series-parallel, formed a variety of voltage levels, a variety of battery capacity, in order to meet the diverse needs of switch power supply and UPS backup battery.
2 performance advantages
At present, the telecommunication operators use a lot of valve control type sealed lead acid battery, after decades of construction and operation maintenance, mainly to solve the problems of the following: a) of low energy weight ratio and volume ratio, battery weight is heavy, covers an area of big, to floor load-bearing and room area, high demand for rooms bring greater difficulties, the location of the base station. B) high temperature requirements in the running environment. Valve control type sealed lead acid battery can be normal working temperature range is narrow, generally at 25 ℃ or so, for the average base station will therefore increase the running energy consumption of air conditioning. For the environment is relatively poor base station, repeater stations and other outdoor integration due to the large range of temperature change, the service life of valve control type sealed lead acid battery can shorten greatly. C) to charge and discharge efficiency is low. With the increase of charge and discharge frequency, charge and discharge efficiency will gradually decline. D) valve control type sealed lead acid battery service life is shorter, the base station in general use fixed number of year is about 3 ~ 5 years. E) lead-acid battery pollution to the environment. Extensive use of lead in lead-acid battery, and lead is a heavy metal, can cause harm to human body and environment.
Therefore, looking for new energy equipment application becomes the focus in the field of communications. Lithium iron phosphate batteries and the main performance comparison valve control type lead acid storage battery, lithium iron phosphate battery volume and weight with only about a third of valve control type lead acid storage battery capacity, for the computer room, site selection of base station has brought great convenience. At the same time, the lithium iron phosphate battery discharge ratio characteristics significantly better than that of lead-acid batteries. Within 1 c discharge of the lithium iron phosphate batteries have little impact, and lead acid battery 1 c discharge capacity only about 50%. In addition, the lithium iron phosphate battery wide working temperature range, high temperature have little impact on battery life, within the scope of the 20 ~ 75 ℃, its discharge characteristics, almost not influenced by high temperature. Applied to the base station can increase the temperature of the air conditioning or turn off air conditioning, by reducing the air conditioning energy consumption to achieve the effect of energy saving.
In addition, the lithium iron phosphate battery charge and discharge cycles is about valve control type lead acid battery 2 ~ 3 times, has excellent economic benefit. Lithium iron phosphate batteries because do not contain any heavy metals and rare metals, are in the process of production and the use does not produce pollution, which is its instead of valve control type lead acid storage battery used in the communications industry an important advantage.
3 application scenario analysis and recommendations
According to the technical characteristics of the lithium iron phosphate battery, based on a large telecommunication operators of backup battery using the environment, for example, is recommended in the following scenario application and popularization of lithium iron phosphate batteries.
1) grid quality is bad, frequent blackouts base station due to the lithium iron phosphate battery charge-discharge cycles, service life is longer, especially suitable for mains quality is poorer, charge and discharge frequently base station.
2) central room area more tension and low bearing performance of acer station due to the lithium iron phosphate battery small volume, light weight, the base station with the battery generally no longer bearing reinforcement, houses can meet the basic requirements, room area is relatively nervous acer station to the city centre, site selection can greatly reduce the difficulty.
3) the integration of outdoor base station
Due to the mobile company is the newly built station rental room more and more difficult, a large number of base stations, base station began to gradually adopt outdoor integration placed on the roof or clearing, solved the difficult problem of rental room. The high temperature of the lithium iron phosphate battery charge and discharge characteristics, general guarantee without air conditioning, meet ventilation conditions, and the life not because of the high temperature and wreck, very suitable for outdoor integration base station.
4) indoor power distribution of the base wall
Due to the lithium iron phosphate battery small volume, light weight, can be used as a backup battery wall hanging switch power supply, improve the safety and reliability of the wall to hang the power.
5) communication board room of the distributed power supply