Nickel hydride battery is composed of hydrogen ion and nickel metal synthesis, power reserve is 30% more than nickel-cadmium batteries, lighter than nickel-cadmium batteries, the service life is longer, and has no pollution to the environment, no memory effect.
The disadvantage of nickel-hydrogen battery is that the price are much expensive than nickel-cadmium batteries, the performance is worse than lithium battery.
Lithium ion battery is a kind of high energy density batteries. Lithium ion battery also a intelligent battery, it can be associated with special original intelligent charger, to achieve the most short charging time, maximum life cycle and the maximum capacity. Lithium ion battery performance is currently the best battery. With the same size nickel-cadmium batteries, nickel-hydrogen batteries reserve maximum power, the lightest weight, the longest life expectancy, charging time is short, no memory effect. Rechargeable battery mainly have two kinds of lead-acid batteries and alkaline batteries. Currently used nickel-cadmium, nickel-metal hydride and lithium ion battery are alkaline battery. NiMH battery’s positive plate material is NiOOH, negative electrode materials is hydrogen storage alloy. The electrolyte is usually 30% KOH aqueous solution, and adding a little amount of NiOH. Diaphragm using porous non-woven fabric or nylon nonwoven. NiMH battery has cylindrical and square two kinds.
NiMH battery has better low-temperature discharge characteristics, even at -20 ambient temperature, using a large current (1C discharge discharge rate ) dischange, the release of electricity can also reach the nominal capacity of more than 85%. However, NiMH battery at a high temperature ( 40), storage capacity will drop from 5 to 10%. This due to discharge ( the higher the temperature, the greater the self-discharge rate ) caused the capacity loss is reversible, a few charge-discharge cycle can return to maximum capacity. NiMH battery open circuit voltage is 1.2V, the same with NiCd cells.
The NiCd and NiMH battery charging process is very similar, were required constant current charging. The difference is mainly in the fast charge termination detection methods, in order to prevent overcharge. Charger charging with constant current for battery, detect battery voltage and other parameters at the same time. When the battery voltage rise slowly to reach a peak, the NiMH battery fast charge termination, and NiCd battery when the battery voltage drops first a - ³V is terminated when a rapid charging. To avoid damage to the battery, while the battery temperature is too low it should not start charging, when the battery temperature below 10 , should be transferred to a trickle charge mode. While the battery temperature reaches the prescribed value, it must be immediately stop charging.
According to metal powder supplier, negative plate active material is composed by cadmium oxide powder and iron oxide powder, the role of iron oxide powder is made the cadmium oxide powder with higher diffusivity, prevent caking, and increased the capacity of plate. Nickel cadmium battery NiCd battery positive plate active material is made of oxidized nickel powder and graphite powder, graphite is not participating in a chemical reaction, its main role is to enhance the conductivity. Active substances are wrapped in a perforated, after compression molding is formed the battery positive / negative plate. Plate by alkali-resistant rubber insulated stick or perforated PVC corrugated board. The electrolyte is usually in potassium hydroxide solution. Compared with other battery, NiCd battery self-discharge rate ( i.e. the battery when not in use without charge rate ) is moderated. NiCd battery during use, if the discharge is not completely and charge again, next time when discharging will not release all energy. For example, released 80% electricity then fully charged, the battery can only emit 80%. This is the so-called memory effect. Of course, several full charge / discharge cycle will make NiCd cells recovered to normal. Because of NiCd battery memory effect, if not fully discharged, should be in charge before each battery discharge to 1V below.
Source:http://www.mhcmp.com
The application of tungsten in various industries
Steel Industry Most of tungsten applied in the production of special steels. The widely used high-speed steel was containing 9-24% of tungsten, 3.8-4.6% of chromium, 1-5% of vanadium, 4-7% of cobalt, 0.7-1.5% of carbon.
Magic effects of coconut oil
According to records, coconut oil can be regarded as the nobility of skin care plant extracts. It was rich in exotic tension of tropical plants, which can enhance the contractile force of the pores, perfectly beautify and nourish the skin.
Exploring the Potentials of Nano-Aluminum Powder
Nano-aluminum powder, a material with remarkable properties due to its minuscule particle size, is revolutionizing various industries with its high reactivity and large specific surface area. Unlike its bulk counterpart, nano-aluminum powder begins to oxidize at a lower temperature of 550°C, compared to the 950°C oxidation point of ordinary aluminum. This lower ignition energy and full combustion without apparent cohesion make it a superior choice for applications requiring high energy and efficiency. The unique characteristics of nano-aluminum powder, such as faster burning rates and greater heat release, are largely influenced by its synthesis method, which determines its particle size, surface area, and shape.
