Special

Project Introduction: at present, lithium ion batteries mainly use carbon negative electrodes, with a theoretical capacity of 372mag/g. With the introduction of high energy density, safety, with higher rate of charge and discharge and other requirements, the theoretical specific capacity of silicon negative pole can reach 4200mAh/g, and at the same time it has lower working voltage, which is recognized as the negative pole material of the next generation lithium ion battery in the industry. However, compared with the graphite negative pole, the Silicon negative pole faces a larger volume expansion in the process of charging and discharging, and the volume expansion rate can reach 360%. At the same time, the material particles are powdered, active materials are easy to weaken the adhesion with the collector and form unstable SEI, which affects the circulation performance. In addition, the SEI phase generated by irreversible charge and discharge of silicon in the first week will seriously reduce the first Coulomb efficiency of the battery, and will also affect the conductivity of the whole electrode system.

Project Introduction: carbon nanotubes, also known as Pakistan tube, were discovered by Japanese scientists in 1991. They are of nanometer radial size and micrometer axial size, one-dimensional quantum material whose two ends are basically sealed. Compared with other nanomaterials, they have more unique structures and strange properties, and are called "The King of nanomaterials". Carbon nanotubes have unique physical and chemical properties, which make them have better conductivity, thermal conductivity, super tensile and adsorption effects. At present, it has good application as an additive in the fields of electronics, composite materials, energy and so on. However, single-walled carbon nanotubes can achieve the effect of adding additives with the minimum additive amount. Especially in the field of lithium ion battery, it plays a key role in the development of battery energy. Compared with the addition of multi-walled carbon nanotubes, the addition of single-walled carbon nanotubes can be reduced to 1/10 or even lower than the original one, therefore, the development of single-walled carbon nanotubes is imperative.

Through the development of this project, the processing technology of batch preparation of single-walled carbon nanotubes is obtained.

The project is currently in progress.

Project Introduction: because of the high surface activity of carbon nanotubes, high adsorption force among particles, strong electrostatic force and van der Waals force between surface molecules and atoms, as a result, carbon nanotubes will have strong winding and agglomeration phenomena, and it is difficult to evenly disperse them in lithium battery electrode materials, therefore, it is necessary to uniformly disperse the carbon nanotube powder into a single carbon nanotube in the liquid phase medium, that is, to make conductive paste for use. Combined with the advantages of carbon nanofibers, the magnification and cycle performance of lithium ion batteries will be further improved when both of them are used together.

Through the development of this project, different specifications and models of conductive paste are developed for different application scenarios.

The project is currently in progress.