The power, the key will have to see batteries. Mobile power internal batteries is like a car's fuel tank and transmission, is responsible for the entire endless power mobile power, mobile power directly determine good or bad. Mobile power board can be seen as the control system is mainly responsible for the distribution of power and the conversion, the lithium batteries are provided 3.7V (or higher) voltage is converted into a standard 5V (or higher) voltage to was to provide electricity for the charging equipment.
The current mobile power batteries generally use lithium-ion batteries, but the performance varies, but is from the shape does not look like, and generally can not be reflected in the specification label. Here we start from the batteries, step by step to explore the mysterious world of mobile power.
Lithium-ion battery electrolyte according to the different materials used, can be divided into liquid lithium-ion battery (LIB) and lithium-ion polymer battery (LIP) into two categories. Both positive and negative materials used are the same, including lithium cobalt oxide cathode material, nickel-cobalt-manganese and lithium iron phosphate materials are three extremely negative graphite, battery works are basically the same.
The main difference lies in the type of electrolyte, wherein the liquid lithium-ion battery using a liquid electrolyte, lithium ion polymer batteries places instead of the solid polymer electrolyte. Such polymers may be "dry state", it can be "colloidal", and now most use of polymer gel electrolyte.
Lithium cobalt oxide is known to everyone in liquid lithium-ion battery, a common morphology 18650 and squares shapes. 18650 is the diameter 18 mm, height 65 mm cylindrical battery (looks like a larger version of the 5th battery), widely used in laptop batteries. As with the universal laptop battery, now available in more than 60% of the mobile power is also used in 18650.
Current commercial lithium ion batteries are basically optional layered structure lithium cobalt oxide as the positive electrode material, the theoretical capacity of 274mAh / g, the actual capacity of 140mAh / g or so, there are also reports the actual capacity has reached 155mAh / g.
The higher operating voltage cathode material (average working voltage of 3.7V), charge and discharge voltage stable, small size, high specific energy, cycling performance, high conductivity, the production process is simple, easy to manufacture.
Main advantages: mature technology, wide range of applications, compact size.
The main disadvantage: about 300 times cycle life, low security, anti-overcharge poor, not suitable for high-rate charge and discharge, pollution of the environment after disposal.
Two, nickel, cobalt and manganese (LiNiCoMnO2)
Nickel, cobalt and manganese, also known as ternary material (LiNiCoMnO2), is a polymer lithium ion battery, a common form of soft pack box shape. Notice can also be made of lithium cobalt box shape, but after forming a hard, Yong Shounie click to distinguish them.
Ternary materials with the popularity of smart phones to the rapid development in recent years, the use of more and more areas. It nickel salt, cobalt salt, manganese salt as raw materials, nickel-cobalt-manganese ratio can be adjusted according to actual needs.
Ternary materials made with respect to the positive battery safety lithium cobalt oxide, lithium cobalt oxide higher than life, reaching 500 times using life cycle.
Key Benefits: Volume diversity, the use of a very wide range, not an explosion, high safety factor.
The main disadvantage: higher prices, after disposal pollutes the environment, high-current charge and discharge performance is weak.
Three, lithium iron phosphate (LiFePO4)
Generic ferroelectric lithium iron phosphate, with the previous two batteries biggest difference is added to the iron battery positive. Lithium iron recent years has just started, is a promising material, its safety performance and cycle life are unmatched by other materials, these battery power is also the most important technical indicators. Charge-discharge cycle life up to 2000 times, single battery charging voltage 30V no burning, no explosion puncture.
Lithium iron phosphate cathode material to make more large-capacity battery pack used in tandem to meet the electric car needs frequent charging and discharging, and has a non-toxic, non-polluting, good safety performance, wide range of sources of raw materials, cheap, long life and other advantages, is ideal for a new generation of lithium-ion battery cathode material.
Currently ferroelectric with large capacity electric bus, signal the base station based energy storage and large UPS applications, including mobile power, AA batteries just beginning to test the water mass production, which makes the ferroelectric phase in large-capacity UPS, compact storage batteries , lawn, electric tools are widely used.