Keywords: silicon nanopowder, nano silicon powder, Si, lithium-ion battery; anode material; nano-composite films
Lithium-ion batteries have high voltage, high specific energy, no memory effect, no pollution, etc., has become one of the main choice of green cells in the 21st century. Currently lithium-ion battery anode material is mainly used commercial carbon-based anode material, but only a theoretical capacity of 372 mAh carbon Kuang 1, unable to meet the next generation of new lithium-ion battery cathode material for high-capacity requirements. Therefore, the development of new non-carbon anode materials is of great significance for the development of lithium-ion batteries.
On this point, after years of painstaking Hongwu Nano graduate output nanometer particle size at 30-50 nm, 99% purity nano-silicon powder, the powder as the anode material for lithium-ion batteries to replace traditional graphite materials. Pilot test of our customers have successfully proven silicon metal nanopowders has good capacity performance, is now 3-5 times graphite products.
Characteristic of lithium-ion battery:
Compared with other secondary batteries, lithium-ion battery has the following advantages:
1. Open circuit voltage is high. Currently, the commercialization of lithium-ion battery platform is up to 3.6-3.7 V, triple nickel-cadmium and nickel-hydrogen batteries. Thus the need for high voltage use of the occasion, the number of batteries connected in series with a lithium-ion battery needs a small, space utilization, small mutual influence between the battery, such as a mobile phone using single cell lithium-ion battery is enough, if NiMH battery requires three electrochemical properties very similar to single cells in series, for use in the process of charging and discharging, the battery due to the electrochemical properties of the three can not be completely the same and thus influence each other, reducing their life.
2. High energy density. Currently the energy density lithium-ion polymer battery made up to 190 Wh Kg-1, 380Wh L. 1, is approximately four times the nickel-cadmium batteries, nickel-hydrogen battery is about twice the.
3. Can be large current charge and discharge, can fully meet the power requirements of cameras and other equipment.
4. A substantial increase in safety performance than lithium batteries, long cycle life. Lithium-ion battery using a lithium intercalation compound as the negative electrode, the discharge to avoid the formation of lithium dendrites, the battery safety performance is significantly improved. In the electrochemical reaction, the electrolyte does not participate in the reaction, Li + is embedded between the positive and negative deintercalation, such as concentration cell, it is called rocking chair battery, so a relatively long cycle life, up to 1200, far more than the nickel-cadmium batteries and nickel-hydrogen batteries.
5. Self-discharge. Month self-discharge is less than 10%, less than 20% of nickel-cadmium batteries, nickel-hydrogen battery to 30%. In the first lithium ion battery during charging the carbon negative electrode surface is formed in the solid electrolyte layer of the intermediate phase (SEI film), which allows ions to pass through, but does not allow the electron passage, it can better prevent self-discharge.
6. No memory effect, environment-friendly. Lithium ion secondary battery does not contain lead, cadmium, mercury and other toxic substances, environmental pollution is a very small system.
In summary, the lithium-ion battery has excellent overall performance. Lithium-ion batteries are mainly used in small mobile electronic devices. With the developing of technology, lithium ion battery as battery could be used in electric vehicles.