At present, the most suitable battery for solar street lamps is lithium iron phosphate battery and ternary lithium battery. Let us take a look at the difference between them, what are the advantages and disadvantages?
Lithium iron phosphate battery（LiFePO4）:
The lithium iron phosphate battery refers to a lithium ion battery using lithium iron phosphate as a positive electrode material. This type of battery is characterized by the absence of precious metal elements (such as cobalt). In actual use, the lithium iron phosphate battery has the advantages of high temperature resistance, strong safety and stability, low price and better cycle performance. The price of raw materials is low, and phosphorus and iron are abundant in the earth’s resources, and there is no problem of feeding.
Advantages of lithium iron phosphate battery:
1. use security
The P-O bond in the lithium iron phosphate battery crystal is stable and difficult to decompose, and does not collapse or heat like a lithium cobaltate or form a strong oxidizing substance even at a high temperature or overcharge, and thus has good safety. The lithium iron phosphate battery undergoes rigorous safety testing, and even if it collides, the puncture will not explode.
2. the improvement of life
Lithium iron phosphate power battery has a cycle life of more than 2,200 times and can be used up to 2,200 times with standard charging (5 hour rate). The same quality lead-acid battery will last up to 1~1.5 years, while the lithium iron phosphate battery will be used under the same conditions, and the theoretical life will reach 12 years.
3. high temperature performance
The lithium iron phosphate battery has a thermal peak of 350 ° C to 500 ° C, while lithium manganate and lithium cobalt oxide are only around 200 ° C. Wide operating temperature range (-20C–75C), with high temperature resistance.
4. large capacity
The battery is often operated under full load and the capacity will quickly fall below the rated capacity. This phenomenon is called the memory effect. There are memories like nickel-metal hydride and nickel-cadmium batteries, but lithium iron phosphate batteries do not have this phenomenon. No matter what state the battery is in, it can be used with charging, no need to discharge and recharge.
6. light weight
The volume of the lithium iron phosphate battery of the same specification capacity is 2/3 of the volume of the lead-acid battery, and the weight is 1/3 of the lead-acid battery.
7. environmental protection
Lithium iron phosphate battery is non-polluting and meets European RoHS regulations. It is an absolute green battery certificate.
8. fast charging
High current 2C can be quickly charged and discharged. The battery can be fully charged within 1.5 minutes of 1.5C charging under a dedicated charger. The starting current can reach 2C.
Disadvantages of lithium iron phosphate battery:
- The tap density of the positive electrode of lithium iron phosphate battery is small, and the density is generally about 0.8 to 1.3. Big size.
- The conductivity is poor, the diffusion speed of lithium ions is slow, and the actual specific capacity is low when charging and discharging at high times.
- The low temperature performance of lithium iron phosphate battery is poor.
- The life of a single battery of lithium iron phosphate battery is about 2,000 times, but the life of lithium iron phosphate battery pack is short, generally about 500 times.
Ternary lithium battery:
As the positive electrode material, a nickel-cobalt-manganese hydride (Li(NiCoMn)O2) ternary positive electrode material and graphite as a negative electrode material lithium battery were used. Unlike lithium iron phosphate, the voltage platform of the ternary lithium battery is very high, which means that the specific energy and specific power of the ternary lithium battery are larger under the same volume or weight. In addition, ternary lithium batteries have great advantages in terms of large rate charging and low temperature resistance.
Advantages of ternary lithium battery:
- The voltage platform is high. The higher the voltage platform, the larger the specific capacity, the same volume, weight, and even the same battery, the higher the voltage of the ternary material lithium battery battery mileage is farther. The voltage platform of the ternary material is significantly higher than lithium iron phosphate, the high line can reach 4.2 volts, and the discharge platform can reach 3.6 or 3.7 volts.
2, high energy density. With high storage energy density, has reached 460-600Wh / kg, about 6-7 times that of lead-acid batteries
3, light weight, the weight of the same volume is about 1/6-1/5 of lead-acid products
4, Self-discharge rate is very low, which is one of the most prominent advantages of the battery, generally can do less than 1% / month, less than 1/20 of the nickel metal hydride battery
Disadvantages of ternary lithium battery:
- Lithium primary batteries have poor safety and there is a danger of explosion.
- The lithium ion battery of lithium cobalt oxide can not discharge at a large current, and the price is expensive and the safety is poor.
3, lithium-ion batteries need to protect the line to prevent the battery from being overcharged and discharged.
- High production requirements and high cost.
5, the use of conditions are limited, high and low temperature use is dangerous. 3, poor life
6, the element is toxic, the temperature of the ternary lithium battery after the high power charge and discharge sharply rises, the release of oxygen after high temperature is very easy to burn.
The difference between lithium iron phosphate battery and lithium battery
Lithium iron phosphate batteries are not the same as lithium batteries.
- Lithium iron phosphate battery is used to make lithium ion secondary battery. Now the main direction is power battery. Compared with NI-H, Ni-Cd battery has great advantages.
- A lithium battery is a type of battery that uses a lithium metal or a lithium alloy as a positive electrode material and uses a nonaqueous electrolyte solution. The chemical properties of lithium metal are very active, making lithium metal processing, storage, and use very demanding on the environment.
3, lithium iron phosphate puncture does not fire does not explode, lithium battery will.
4, lithium iron phosphate resistant to overcharge to 100% will not cause fire and explosion; lithium battery reaches the specified value will be gassing bulging.
Biggestne battery introduction
Biggestne integrated street light classic series BG-SSL all use lithium iron phosphate battery, and this year in order to reduce weight and volume, under the prevailing conditions, the BG-SSN series, using ternary lithium battery, currently supports 24W and 36W . In order to ensure the safety of street lamps, Biggestne has added an IC to the controller to protect the battery. This protects the battery completely and completely eliminates the safety hazard of the battery.