Views: 0 Author: Site Editor Publish Time: 2022-04-26 Origin: Site
Lithium power battery is a new type of high-energy battery. The negative electrode of this battery is metal lithium, and the positive electrode is MnO2, SOCl2, (CFX) n, etc. In the 1970s, it became practical. Because it has the advantages of high energy, high battery voltage, wide working temperature range, and long storage life, it has been widely used in military and civil small electrical appliances, such as mobile phones, portable computers, cameras, cameras, etc. High capacity lithium batteries have been used in electric vehicles.
1. The working voltage of the single battery is as high as 3.7V, which is three times that of nickel-cadmium battery and nickel-hydrogen battery, and nearly twice that of lead-acid battery, which is also an essential reason for the high specific energy of lithium power battery. Therefore, when forming a power battery pack with the same voltage, the number of lithium power batteries in series will be much less than that of lead-acid batteries and Ni MH batteries. The more the number of single batteries in the power battery, the higher the consistency requirements of the single batteries in the battery pack, and the longer the service life is. After the analysis of the problems of the battery pack in the actual use process, generally one or two single batteries have problems, which leads to the problems of the whole battery. Therefore, it is not difficult to understand why the feedback of 48V lead-acid battery is higher than that of 36V lead-acid battery; From this point of view, lithium batteries are more suitable for power batteries.
2. Lightweight and high specific energy: up to 150wh / kg, which is twice that of Ni MH battery and four times that of lead-acid battery. Therefore, the weight is one-third to one-quarter that of lead-acid battery with the same energy. From this point of view, lithium battery consumes less resources. Moreover, due to the large reserves of elements used in lithium manganate battery, the price of lead-acid battery and Ni MH battery may be further increased, and the cost of lithium power battery will be further reduced. The weight of lithium battery for electric bicycle is 2.2-4kg, the weight of lead-acid battery is 12-20kg, and the weight of lithium battery is about one quarter to one third of that of lead-acid battery, which is about 10kg lighter than lead-acid battery (36V, 10Ah battery). The weight of the battery is reduced by 70% and the total weight of the whole vehicle is reduced by at least 20%. In addition, the general lithium tram is a simple electric bicycle. Due to the light battery and the whole vehicle, the driving mileage of the battery with the same voltage and capacity is longer. The weight of the ordinary electric vehicle is more than 40 kg, while the weight of the lithium battery electric bicycle is between 7 and 26 kg. Women and the elderly can easily move it, and the human riding is also very light. It has both sports and leisure.
3. Small volume: up to 400wh / L, the volume is one-half to one-third of that of lead-acid battery. It provides the design conditions, design space and possibility of more reasonable structure and more beautiful appearance. At this stage, due to the limitations of the volume and weight of lead-acid batteries, the design ideas of designers are greatly constrained, resulting in the "one side of one thousand cars" in the structure and appearance of electric bicycles at this stage, which are similar and monotonous. The use of lithium batteries provides designers with greater space and conditions to display design ideas and design styles. Of course, it also leads to a variety of sizes of lithium power batteries for electric bicycles, which is not conducive to the development of lithium power battery industry. The lithium power battery industry also needs to formulate national standards for lithium batteries for electric bicycles as soon as possible, and accelerate the replacement of lithium batteries for lead-acid batteries in the field of electric bicycles. Of course, lithium batteries are in the process of continuous development. Different materials and processes have great differences in the volume of batteries, and how to unify them is also a difficulty.
4. Long cycle life: up to 1000 cycles. Based on the capacity of 60%, the number of 100% charge and discharge cycles of the battery pack can reach more than 600 times, the service life can reach 3-5 years, and the service life is about two to three times that of the lead-acid battery. With the innovation of technology and the improvement of equipment, the service life of battery will be longer and longer, and the cost performance will be higher and higher.
5. Low self discharge rate: less than 5% per month.
6. Wide allowable working temperature range and good low-temperature performance: lithium power battery can work between - 20 ℃ and + 55 ℃, which is especially suitable for low-temperature use, while the performance of aqueous solution battery (such as lead-acid battery and nickel-hydrogen battery) will be greatly reduced due to the poor fluidity of electrolyte at low temperature.
7. No memory effect: therefore, it is not necessary to discharge like nickel-cadmium battery and nickel-hydrogen battery before each charging, and it can be charged anytime and anywhere. The depth of battery charge and discharge has little impact on the service life of the battery. It can be fully charged and fully discharged. Our cycle test is fully charged and fully discharged.
8. Especially suitable for power battery: in addition to the high voltage of lithium battery, the protection board of lithium power battery pack can carry out high-precision monitoring of each single battery and low-power intelligent management. It has perfect overcharge, over-discharge, temperature, overcurrent, short-circuit protection, locking self recovery function and reliable balanced charging function, which greatly prolongs the service life of the battery. While other types of batteries (such as lead-acid batteries) are prone to overcharge and over-discharge due to battery consistency, charger and other problems during use (due to cost and other reasons, each single battery cannot be monitored and protected in the lead-acid battery pack)
9."green battery", which is supported by the state. Due to the existence of harmful substances lead and cadmium in lead-acid batteries and cadmium nickel batteries, the state is bound to strengthen supervision and Governance (the cancellation of export tax rebate of lead-acid batteries, the increase of lead resource tax and the restriction of export of lead-acid electric bicycles), and the cost of corresponding enterprises will also increase. Although the lithium battery has no pollution, from the perspective of resource conservation, the recycling of lithium power battery, the safety in recycling and the cost of recycling also need to be considered.
10. There are potential safety hazards: due to the high energy and poor material stability of lithium power batteries, lithium batteries are prone to safety problems. The world-famous manufacturers of mobile phone and notebook batteries (lithium cobalt oxide and ternary materials) and Japanese companies such as Sanyo and Sony require that the explosion rate of the battery be controlled below 40 ppb (one billionth), and it is good for domestic companies to reach ppm (one millionth), The capacity of power battery is more than 100 times that of mobile phone battery, so the safety requirements of lithium battery are very high. Although lithium cobalt oxide batteries and ternary materials have the advantages of lighter weight and smaller volume, they are not suitable for power batteries in electric vehicles.
11. High price: the price of lithium power battery with the same voltage and capacity is 3-4 times that of lead-acid. With the expansion of lithium power battery market, the reduction of cost, the improvement of performance and the increase of lead-acid battery price, the cost performance of lithium power battery is likely to exceed that of lead-acid battery.