Which is better, lithium battery or Ni-MH battery?

Which is better, lithium battery or nickel-metal hydride battery? First of all, in which aspect of the product should the battery be used, and secondly, the economic benefits of the product should be compared to better understand lithium battery and nickel-metal hydride battery Which battery is better. For example, lithium batteries are more suitable for mobile phones than nickel-metal hydride batteries, but when using digital cameras, because the power demand flow of digital cameras is quite large, and the consumption of electricity is much larger than that of mobile phones, in the part of the large current output, nickel-metal hydride batteries are Slightly better. Let's take a look at the advantages and disadvantages of lithium batteries and nickel-hydrogen batteries: the advantages and disadvantages of nickel-hydrogen batteries: the advantages of nickel-hydrogen batteries 1. The energy density is high, 1.5 times that of nickel-cadmium; 2. The battery voltage is 1.2v -1.3v, equivalent to a nickel-cadmium battery; 3. No memory effect, long cycle life; 4. Large current discharge, strong overcharge and overdischarge resistance; 5. No pollution, green, environmentally friendly battery. Disadvantages of nickel-metal hydride batteries: 1. The price is higher than that of nickel-cadmium batteries, and the cathode material is a rare earth alloy material; 2. High self-discharge speed. Advantages and disadvantages of lithium batteries: Advantages of lithium batteries a. High voltage: The operating voltage of a single battery is as high as 3.7-3.8v (the maximum charging voltage of the battery is 4.2v), which is three times that of nickel-cadmium batteries and nickel-h batteries . B. Large specific energy: The actual specific energy that can be achieved at present is about 555Wh/kg, that is, the specific energy of the material can reach more than 150mAh/g (3-4 times of ni-cd, 2-3 times of ni-mh) , Which is close to about 88% of its theoretical value. C. Long cycle life: Generally, it can reach more than 500 times, or even more than 1000 times, and lithium iron phosphate can reach more than 2000 times. Regarding low-current discharge electrical appliances, the battery life will double the competitiveness of electrical appliances. Good safety performance, no pollution, no memory effect. As the predecessor of Li-ion of lithium battery, metal lithium formed by dendritic short circuit is very easy, reducing the application field: Li-ion does not contain cadmium, lead, mercury and other elements in environmental pollution: some processes (such as sintering) Ni-Cd battery has a memory effect, which is a serious battery, but Li-ion does not have this problem. E. A small amount of self-discharge: The self-discharge rate of fully charged lithium ion after 1 month storage at room temperature is about 2%, which is much lower than the 25-30% of nickel-cadmium and 30-35% of nickel-hydrogen. F. Fast charge and discharge: The charge and discharge capacity can reach more than 80% of the nominal capacity in 30 minutes. Now the ferro-phosphorus battery can reach 90% of the rated capacity within 10 minutes. G. Large working temperature range: working temperature is -25~55℃. With the improvement of electrolyte and positive electrode, it is expected that the working temperature can be relaxed to -40~70℃. Disadvantages of lithium batteries: Answer: Aging: Unlike other rechargeable batteries, the capacity of lithium batteries decreases slowly, not because of the quantity used, but because of the temperature. The possible mechanism is the gradual increase in internal resistance, so that electronic components with high operating currents are easier to show. Replacing graphite with lithium titanate seems to extend its life. The relationship between storage temperature and permanent loss rate of capacity: storage temperature 0℃ storage temperature 25℃ storage temperature 40℃ storage temperature 60℃ 40%~60% 2%/year 4%/year 15%/year 25%/year 100%6 %/Year 20%/year 35%/year 80%/year June B. Intolerance of overcharging: During the overcharging process, too much embedded lithium ions will be permanently fixed in the lattice and cannot be released again, resulting in the battery The life is short and the gas production is large, resulting in air bulging. C. Intolerance of over-discharge: In the process of over-discharge, the electrode is deintercalated by too much lithium ions, which causes the collapse of the crystal lattice, shortens the life span, shortens the gas production, and causes air bulging. D. Need multiple protection mechanisms: Lithium batteries are designed with multiple protection mechanisms. Improper use will reduce the life span and even cause an explosion. Protection circuit: prevent overcharge, overdischarge, overload, and overheating. Vent: To prevent excessive pressure inside the battery. Diaphragm characteristics: high resistance to puncture, preventing internal short circuit; when the internal temperature of the battery is too high, it will also melt to prevent the emergence of lithium. Statement: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete it. A: What is the mechanism of charging protection for lithium iron phosphate batteries?