Comparison and analysis on conventional lithium-ion batteries conductive agent materials

Source: 2020 - 03 - Review: 23 14:53 hits: traditional lithium-ion batteries conductive agent has been widely used comparative analysis of commercial lithium-ion batteries, lithium-ion batteries in charging and discharging process of the appearance of the anode materials is the battery discharge, the lithium ions in the positive active material hole, if the current increasing polarization, it is difficult to discharge, so the poor electronic conductivity and electrical conductivity of active material between the province alone is not enough, in order to guarantee the electrode has the prominent function of charge and discharge, when making panel will usually add a certain amount of conductive agent, the micro electric current between the active material and the fluid collection. Summary of conductive material for lithium ion batteries conductive agent, the first use of conductive agent is super p, ks - 6, conductive graphite, carbon nanotubes, graphene, carbon fiber VGCF, etc. These conductive agent each have advantages and disadvantages. Specifically: 1, SP at present, the domestic lithium ion battery conductive agent is mainly conventional conductive agent SP. Carbon black has good ionic conductivity and electrical conductivity, because the product of carbon black, with large specific surface area, so it is advantageous to the electrolyte adsorption and ionic conductivity. In addition, the carbon particles aggregate to form branched chain structure, with the active data can form the conductive structure and help improve the electronic conductivity of the data. 2. Graphite conductive agent is basically artificial graphite. Compared with the artificial graphite cathode materials, artificial graphite as conductive agent, particle size smaller, promotes the compaction of polar particles, improve the ionic and electronic conductivity. 3. Ask conductive agent high-end digital battery use of more than 50%, and the use of power battery share comparatively low. But in recent years, as the power battery for energy density, multiplier function, cycle life, such as the gradual improvement of the functional requirements, the use of CNT conductive agent share increase gradually. Kochi black Cochin black only need low incremental can achieve very high conductivity, so Cochin, black is the best in the conductive carbon black, is in the leading position in the market for a long time. Compared with other used for battery of conductive carbon black, qin carbon black has a unique shape of branched chain. This shape of the conductive body, there are a lot of the advantages of the conductive contact form more conductive path and branch chain, so that we can achieve very high electrical conductivity and little increment ( Other carbon black are mostly globose or flake, so it requires a very high power needed for the incremental implementation) 。 Cogene black is on the leading edge of the super conductive carbon black, the current lithium electricity top ten are in use or experiments. Ec - 300 j is mainly used for nickel metal hydride batteries and nickel-cadmium batteries. ECP and ECP - 600 jd is mainly used for large capacity, high current density of lithium electricity, ECP - among them Especially 600 jd. The industry generally believe that: its superior conductivity and high purity as well as the unique branched chain structure, in the era of lithium iron will provide data show. Batteries used in cochin, black product has two kinds: Carbon ECP, Carbon ECP600JD and CP300JD. The content of conductive agent A) The role of conductive agent on the electrode is to provide the movement of electronic channel if the content is too low, can achieve good function of discharge capacity and cycle. Too high will reduce the relative content of active material and the lower the battery capacity. B) The existence of the conductive agent will influence the distribution of the battery electrolyte system, due to the space of the lithium ion battery limit, electrolyte injection quantity is limited, usually in the barren solution, and the electrolyte battery system internal cohesion is the cathode plasma, the spread of the lithium ion diffusion has a vital influence in the liquid phase. When an electrode conductive agent content is exorbitant, concentration of electrolyte on the electrode in the process of making lithium ion transport in other electrode slow and polarization is high, and it's easy to fail after repeated circulation, which affects the whole function of the battery. C) As conductive agent content reaches an inflection point, too much will only reduce the density of the electrode and the capacity and too little will lead to the electrode active material utilization rate is low, under high rate discharge function decline.