The difference between Ni MH battery and lithium battery
The difference between Ni MH battery and lithium battery
The history of battery development has two historical periods: primary batteries and rechargeable batteries. Up to now, these two historical periods are divided into different stages: one battery has carbon and alkali, the two battery has lead-acid battery, nickel cadmium battery, Ni MH battery and li ion battery. Among them, the lead-acid battery is a unique system, and Ni Cd / Ni MH / Li ion battery has the technology inheritance and time succession. Lithium ion battery is a kind of lithium battery, and lithium battery also includes lithium primary battery (lithium metal battery). Because of the wide application of lithium ion battery, people used lithium battery to refer to lithium ion battery in daily life. It is good to understand the difference between Ni MH battery and lithium battery to understand current and future battery technology. The development direction helps to understand the current situation of the battery industry in the world, and is more representative than the comparison between lead-acid batteries and lithium batteries.
The idea of lithium battery as a battery is not later than nickel cadmium battery. However, the reason why the use of lithium is late is due to the active chemical properties of lithium, so that there are hidden dangers in production, use and transportation. Relying on technological progress to ease these pressures, lithium batteries have become the mainstream of modern battery technology. In practice, lithium batteries are actually developed by gradually gaining the advantage of Ni MH batteries. Sum up, the overall advantage is convenience and durability. The following is a comparison of li ion battery and Ni MH battery.
Ⅰ. energy density: the volume of Ni MH battery is between Ni Cd battery and lithium battery, which shows the transition product properties of Ni MH batteries, because energy density is different, that is the energy that can be stored at the same volume, and the lithium battery is 3 times of the Ni MH battery.
Ⅱ. Self discharge refers to the amount of electricity that the battery loses when it is not in use. The self discharge of Ni MH battery and lithium battery is not large, but the self discharge of Ni MH battery is common, and the too large self discharge will shorten the life of the battery. So about ten years ago, low self discharge Ni MH batteries used to be a bright spot for the promotion of Ni MH batteries, and the self discharge of lithium batteries can be ignored, which is the natural difference in chemical properties of the raw materials used by both.
Ⅲ. No memory effect: The memory effect of Ni MH battery is obvious. The memory of the human is the impression that the brain left in the brain. The Ni MH battery is also the same, the discharge is not complete or the charge is not satisfied. For a long time, the battery can only remember that incomplete and dissatisfied state. The performance of the application is capacity attenuation. While lithium batteries have no such characteristics. Therefore, nimh battery has to discharge once for every certain time to clear the memory left, which is similar to brainwashing. However, lithium batteries can be recharged at any time, so the lithium battery is a "happy battery" and the users are also happy.
Ⅳ. High charging and discharging platform. The voltage of the single lithium battery is 3.6V, the voltage of the monomer Ni MH battery is 1.2V, and the former is 3 times of the latter. Lithium battery charging method is set up a termination voltage, usually monomer 4.2V, Ni MH battery without voltage rise or fall. The charging method of a lithium battery is called the limiting current limiting method (the voltage, the current, the voltage and current setting a upper and lower limit), while the nimh battery has a low voltage platform and usually uses a constant current (a constant current) to charge. Since the charging method is different, li ion battery charger and nimh battery charger can not be mixed.
Ⅴ. Specifications. The name of special-purpose Ni MH battery is often heard on the market, but very few special lithium batteries are heard. This is because lithium batteries are currently mainly used in products with large market capacity. If they are used in small capacity markets, it is not only technology, but also the cost sharing is very difficult. However, the problem of technology and market scale is also improving. Some enterprises in the lithium battery industry have been trying to enter the new field of lithium application in a positive attitude.
The difference between the nimh battery and the lithium battery from the above five aspects shows the advantages of the lithium battery. However, the different forms of the battery products have their own inevitability because of their different chemical properties, so that they will not be completely replaced by other battery forms. So is the carbon electroalkali electricity, and so is the nimh battery. For example, in the field of large current instantaneous discharge, Ni MH batteries are better than lithium batteries, which include medical devices, emergency equipment, power tools, etc. In larger applications, Ni MH batteries can also be used in new energy hybrid vehicles. Of course, there is still a breakthrough in this area.