나노 실리콘 분말은 리튬 배터리의 양극 재료로 어떤 응용 프로그램을 할 수 있습니까?

November 8,2018.

리튬 이온 배터리의 양극 재료, 실리콘 나노 분말 이론적으로 가장 높은 비 용량 (최대 4200 mah / g)을 가지고있어 현재 널리 사용되는 탄소 분말보다 훨씬 높지만 리튬 이온 배터리의 음극 인 실리콘 분말의 가장 큰 단점은 리튬과 합금하는 과정입니다. .
큰 체적 변화의 경우, 활성 물질이 사이클 중에 분리되어 용량이 빠르게 감소하고 사이클 성능이 저하됩니다. 현재이 문제를 해결하기 위해 연구자들은 실리콘 나노 분말 / 티타늄 질화물 나노 분말 / 티타늄 카바이드 나노 분말 as composite materials. Experiments show that they have stable cycle performance, and TiN, TiC and other phases act as inert components to stabilize the structure. Its role is mainly manifested in: during the discharge process, it buffers the volume expansion during the formation of LiSi, inhibits the capacity decay caused by the pulverization of the alloy due to alloy pulverization, and in the charging process, To prevent the agglomeration of Si particles. In addition, TiN, TiC and the like have good electrical conductivity and enhance the conductivity of the electrode. Due to the high absorption rate of nano-silicon and lithium batteries, the use of nano-silicon for lithium batteries can greatly increase the capacity of lithium batteries (theoretical can reach 4000 mA / h).
Silicon nanopowder and graphite powder were used as raw materials to replace carbon nanopowder. As a negative electrode material for lithium battery, silicon/graphite composites were prepared by mechanical ball milling. The materials were characterized by XRD, SEM and electrochemical tests. Performance test. The best ratio of silicon to graphite was found by ball milling different amounts of silicon and graphite, and the corresponding composites were tested for charge and discharge. The value was 1:9. The composition of the Si-C composite material can effectively reduce the expansion due to the absorption of lithium ions by the silicon, and at the same time, the affinity with the electrolyte can be increased, the dispersion is easy, and the cycle performance is improved.
The nano silicon wire is made of nano silicon powder and used in the negative electrode material of the rechargeable lithium battery, or the surface of the nano silicon powder is coated with graphite as the negative electrode material of the rechargeable lithium battery, which can improve the capacity and charge and discharge of the rechargeable lithium battery more than 3 times. Cycles.
The experimental results show that the obtained material not only has higher cycle performance than pure nano-silicon, but also has higher reversible capacity than graphite, and greatly increases the capacity of lithium battery. When the mass ratio of silicon to graphite is 4:6, the capacity decays faster, and the capacity after the 25 cycles is 200 mA.h/g, so the content of silicon in the composite should not be too large. If the content of silicon is large, the graphite is caused.
The silicon is not well dispersed, the chance of contact between the nano-silicon is increased, and agglomeration occurs, and the coulombic efficiency and cycle performance are reduced. When the mass ratio of silicon to graphite is 3:7, the composite after 25 cycles Although the reversible capacity is larger than the reversible capacity when the mass ratio of silicon to graphite is 4:6 (about 240 mA.h/g), the attenuation is still very fast as seen from the curve. The mass ratio of silicon to graphite is 1:9 and 2 At 8 o'clock, the cycle performance is better, and 1:9 is the best.
Since the price of nano-silicon is much higher than that of graphite, it is more economical and purer than the 1:9 ratio of silicon and graphite. Compared with graphite, the first reversible capacity of the composite with mass ratio of 1:9 is greatly improved, which is more than twice that of graphite. The cycle performance is also good, reaching 310mA.h/g after 30 cycles. Silicon and silicon-containing materials as lithium-ion batteries The negative electrode material has a high specific capacity, the theoretical capacity of silicon is 4200 mA.h/g, and the graphite/nanosilicon composite prepared by mechanical ball milling It is used as a negative electrode material for lithium ion batteries.
The composite material exhibits high lithium storage capacity and good graphite cycle performance and small volume effect. The experimental results show that the optimal silicon/graphite mass ratio is 1:9. The performance test shows that the cycle performance of the composite material is greatly improved compared with the pure silicon electrode and has a reversible capacity higher than that of graphite. It is expected to replace graphite as the anode material of the new generation lithium ion battery.

The main purpose:
1. 나노 실리콘 와이어는 리튬 이차 전지의 음극 소재로 사용하기 위해 나노 실리콘 분말로 만들어 지거나, 나노 실리콘 분말 표면에 코팅 된 흑연을 리튬 이차 전지용 음극 소재로 사용하여 충전식 리튬 배터리의 용량 및 충전이 3 회 이상 방전 사이클 수
2. 나노 실리콘 분말 고온 내성 코팅 및 내화 재료에 사용됩니다.
3. 나노 실리콘 분말은 고압 하에서 다이아몬드와 혼합되어 실리콘 카바이드 --- 다이아몬드 복합 재료를 형성하여 절삭 공구로 사용됩니다!

핫 태그 : 티타늄 질화물 나노 분말 실리콘 나노 분말 탄소 나노 분말

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