The difference between lithium battery and electric vehicle lead-acid battery

Lead acid batteries

Among them, the number of lead-acid batteries is the largest. Lead acid batteries are the least expensive and most commonly used. China is the largest producer of lead acid batteries in the world. It contains less contaminated ingredients and has good recyclability. The disadvantage is that it is smaller. In other words, at the same capacity, the battery is heavy and large. The current lead-acid battery is basically developed from a floating type of battery. Floating rechargeable batteries are not suitable for fast charging and large current discharge. Although the technicians have spent a lot of hard work to make effective improvements, they can be used for practical purposes, but their life span is still very unsatisfactory.

The colloidal battery belongs to a kind of development classification of lead-acid battery. The simplest way is to add a coagulant in sulfuric acid to make the sulfuric acid liquid into a colloidal state. Electrolytic, colloidal batteries are often referred to as colloidal batteries. Broadly speaking, the difference between a colloidal battery and a conventional lead-acid battery is not just that the liquid is changed to a gelatinous shape.

For example, non-coagulated aqueous colloids belong to the same colloidal battery from the electrochemical classification structure and characteristics. Another example is the polymer material attached to the grid, commonly known as the ceramic grid, which can also be regarded as an application feature of colloidal batteries. Recently, laboratories have added a targeted coupling agent to the polar plate formula, which has greatly improved the reaction utilization rate of polar plate active substances. According to non-public data, it can reach a weight-to-energy level of 70 WH / kg. These are examples of current industrial practices and applications of colloidal batteries to be industrialized.

The difference between colloidal batteries and conventional lead-acid batteries has been further developed from the initial understanding of electrolyte cementation to the study of electrochemical properties of electrolyte infrastructure and its application in grid and active substances. Its most important feature is that it uses a relatively small industrial cost to produce better batteries along the 150-year-old lead-acid battery industry, with a straight discharge curve and a high inflection point. Compared with energy, especially power, it is more than 20 % larger than conventional lead-acid batteries, and its life span is generally about twice that of conventional lead-acid batteries. The characteristics of high temperature and low temperature are much better.

Lithium-ion batteries

Lithium-ion batteries are better than nickel-metal hydride batteries. For lead-acid batteries of the same capacity, lithium-ion batteries weigh as much as a laptop, so that old women and children can use them. Its life span can also be better than nickel-metal hydride batteries. The current cell phone batteries are basically using this type of battery. The internal resistance of the lithium battery is relatively large. When the battery is about to be completely discharged when used on an electric bicycle, the car's power is not enough. The more important problem with lithium-ion batteries is that the batteries will explode during overcharging and over-discharge. The cell phone batteries are all monolithic batteries used. After good protection circuits are used, the battery explosion problem is basically eliminated. In the use of electric bicycles, it is necessary to use serial batteries, and the protection circuit of serial batteries is far more complex than the protection circuit of individual cells, and the material cost is also greatly increased. At present, the cost of a good lithium battery protection circuit is close to the price of the battery itself. Polymer lithium batteries have less explosive damage than lithium ion batteries, but there is also the possibility of explosion and combustion. This is as much a problem as a lithium-ion battery.

Lead acid battery process simple cost is cheap, the disadvantage of short average service life of 300 to 500 times, volume weight.

The same capacity of lithium batteries is one of the five parts of lead acid weight, and the charge and discharge life is long: the number of electrical charge and discharge times of lithium of ternary polymers is 1,000, and the maximum lithium iron phosphate electric charge and discharge life is 2,000 times. Disadvantages: The price is high so the penetration rate is less than that of lead acid. 90 % of electric cars and tricycles are made of lead acid batteries.

Is lead-acid batteries "really cheap" or "fake benefits"?

We should make a comparison of what we buy accordingly, and have a comprehensive understanding of all aspects. It is also the same for buying electric vehicles. For example: future maintenance, charging and discharging losses, replacement of batteries, etc., will spend a lot of money in the future!

It is understood that the average consumer's electric vehicle replacement cycle is about 4-5 years. Although lead-acid batteries are cheap, they have high annual losses and often need to be changed once a year. In general, the price of a better lead-acid battery is about 600 yuan, so on the same electric car, it will cost about 2,400 yuan to replace the battery.

Take another look at an electric car equipped with a lithium battery. Buy a lithium-battery electric car for about 3500 yuan. Lithium-ion batteries are guaranteed for about three years, which means we don't have to spend extra money to replace them. And the life of lithium batteries is very long, basically about 5 years. In other words, as long as we usually cherish ourselves, there will be no other expenses on electric cars in five years.

With such a contrast, on the surface, the electric car that bought lead-acid batteries was cheaper, in fact, this is a false benefit!

Lithium batteries do not have memory, do not need to pay attention when charging!

When charging the ordinary lead-acid battery electric vehicle, it has always been worried about the memory effect of the battery. After using the lithium battery, everyone can relax. The lithium battery does not have the memory effect, so it does not need to be too careful in the daily charging process!

Lithium battery compared to lead acid battery pollution small!

Lithium batteries are greener than ordinary batteries, have little environmental pollution, and long service life can avoid environmental pollution caused by the replacement of ordinary batteries.

Compared to heavy lead-acid batteries, lithium batteries are light!

Lithium cells are much smaller in size and mass than lead-acid cells. Usually, lead-acid batteries weigh 16-30 kilograms and are larger in size. The weight of lithium batteries is generally 2.5-3 .0 kilograms, and the volume is relatively small, so riding is light and easy to handle. General lithium-battery electric vehicles are light and beautiful, easy to move, and many lithium-battery electric vehicles can also be folded.

Lead acid battery explosive? Lithium batteries are safer to use.

The spontaneous combustion explosion of electric vehicles often occurs. Most of them are caused by battery charging and discharging. Some experts have explained that the charging time of lead-acid batteries is too long. After charging to the end, the two poles are converted into effective substances. If they continue to charge, they will produce a large amount of hydrogen. Oxygen gas. When the concentration of this mixed gas accounts for 4 % of the air, it is too late to escape. If the exhaust hole is blocked or there is too much gas, an explosion will occur when an open fire is encountered. Light damage will damage the battery, and heavy damage will hurt people and damage things. In other words, if the lead-acid battery is overcharged, it will increase the chance of explosion. The lead-acid batteries currently on the market do not have any "overcharge protection", which makes the lead-acid batteries in charging, especially at the end of charging, extremely dangerous.

Today, lithium batteries can evade this problem very well. For example, the smart lithium dog BMS battery management system can provide full protection for the battery. Functions include: charging and discharging high and low temperature protection; Single section overcharge / overcharge voltage protection; Charge/discharge overcurrent protection; Power core equilibrium; Short circuit protection; Charging reminders and so on. The first is to try to extend the battery's service life, and the second is to be more secure.

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