The differences between nickel-metal-hydride and nickel-cadmium batteries:
The working voltage of nickel-metal-hydride and nickel-cadmium batteries is 1.2V However, the specific energy volume of nickel-metal hydride is higher than that of nickel-cadmium batteries. Depending on factors related to the battery manufacturing process, nickel-cadmium batteries have a strong memory effect, while nickel-hydrogen batteries have a very weak memory effect. At the same time, nickel-cadmium batteries contain the heavy metal cadmium, and their use is currently prohibited. However, due to the excellent high-rate discharge performance of nickel-cadmium batteries, nickel-metal hydride batteries cannot replace nickel-cadmium batteries in many power tools. Therefore, the ROSH standard temporarily allows the use of nickel-cadmium batteries in the domgroin of power tools.
The difference between lithium batteries and nickel-metal hydride batteries:
Under the same volume, lithium batteries have larger capacity than nickel-metal hydride batteries , so their call and standby times are longer than nickel-metal hydride batteries. The price is also higher than nickel-metal hydride batteries. In addition, under normal circumstances, nickel-metal hydride batteries cannot be charged at any time, which greatly reduces their convenience.
The development of lithium-ion batteries began with lithium batteries and then developed to lithium-ion batteries. The first negative electrodes for lithium batteries used sheets of pure lithium. This type of lithium battery can easily catch fire and pose a danger. It is on this basis that lithium-ion batteries have been developed.oppées. The negative electrode of lithium-ion batteries is made of graphite. The ionic conductor is made of lithium ions and not metallic lithium. Security is greatly improved.
The working voltage of the lithium-ion battery is 3.7V. The specific energy volume is higher than that of nickel metal hydride. Currently, lithium-ion batteries are available in aluminum shells, steel shells and flexible packaging. occupy the market in their respective fields. Some markets are common, such as lithium batteries for cell phones.
However, since the operating voltage of previous disposable batteries and nickel-metal hydride batteries was 1.2 to 1.5 V, the two connected in series were 2.4 to 3 .0 V. Most electrical devices have already established this operating voltage standard. Such as a portable music player, radio, etc. Thus, in the fieldcivilian batteries, lithium batteries cannot replace nickel-metal hydride batteries. However, new electrical devices developed later, such as MP3, MP4, etc., all use lithium batteries as mobile power sources.
Nickel-metal hydride, nickel-cadmium and lithium-ion batteries cannot therefore be replaced by other batteries in their respective areas.
Ni-MH battery chargers and lithium battery chargers are different, because nickel-metal hydride batteries and lithium batteries are different. The differences between the two are as follows:
1. The difference in battery voltage
The voltage of lithium-ion batteries is 3.7-4.2 V and the voltage of nickel-metal hydride batteries is only 1.2V. The capacity of one lithium-ion battery is equivalent to three nickel-metal hydride batteries connected in series.
2. Differences in memory effects
Lithium-ion batteries do not have a memory effect and can be charged as needed; nickel-metal hydride batteries have a certain memory effect. It is best to fully charge the battery during normal use to avoid affecting its capacity.
3. The difference in charging speed
Since the lithium ions are active and move faster inside the battery, the charging current is greater and the charging speed is faster. Lithium-ion batteries can be fully charged in about 3 hours; Nickel-metal hydride batteries charge more slowly, in about 1 day.
4. Differences in energy density
Lithium-ion batteries have a high energy density. In the first batch of promotional catalogs in 2019, the energy density of electric vehicle batteriesues exceeded 160 Wh/kg; The energy density of nickel-metal hydride batteries is low, only 40 ~ 70 Wh/kg. Therefore, lithium-ion batteries have a higher capacity than nickel-metal hydride batteries in the same volume.