The development of the power battery and the technical development direction

Source: 2020 - 03 - 24 13:56 hits: the development of The Times of power battery and the technical development direction decomposition according to customer's requirements, design gradually decomposition, each process will eventually translate into file input and output, the following product design process are described in details. In the design of the most basic, negative than positive 1 - wide 2 mm, the diaphragm is 2 - wider than negative 4mm。 In order to ensure that uneven do not short circuit batteries, laminated equivalent to parallel a few small electrode, winding is equivalent to a big pole because of the high light aluminum-plastic film quality and utilization of internal space, soft - Coated battery is suitable for the development of the battery has a large energy density, and the metal shell of the internal space constraints, and the average energy density is slightly lower than soft - Coated batteries. Because aluminum metal shell of the battery protection, so security is higher, and flexible packaging battery can only rely on the function of the data itself to pass safety test, now it seems more difficult. In terms of technology difficulty, because the batteries are soft package is a large number of small, so the die cutting equipment demand is higher, prone to self-discharge and part of the micro short circuit, due to the internal space limitation, less free liquid electrolyte, circulation function may be slightly worse. Winding battery is relatively better, a surplus, easy to complete automation production, in terms of cost, because of the high winding battery shell welding requirements, so the cost is slightly high, and flexible battery does not involve the use of laser welding, the focus is on packing, the equipment investment is low. Battery is calculated according to the internal space of the battery is negative, the diaphragm layer, according to the professional conduct, the parameters of the test data of related experiment is based on past experience to test compaction density, information function, the function of auxiliary materials ( Including SBR, validation of CMC, PVDF, conductive agent, etc. ) On the basis of the development of platform type, eventually technology development also needs to match the information, finally it is concluded that the control plan and process flow diagram. Nowadays, in order to shorten the time, manufacturers combined experimental validation and process development, but it is often risky, data system itself is, after all, with the development of skills. Each data of each function has the corresponding test specification, some of the positive and negative function and the function of the battery is directly related to the indicators. However, there is no suitable model to simulate the positive electrochemical action, on the basis of the existing empirical data can only be repaired. Co ratio increase, however, will lead to a drop in battery parameters a and c, c/a of the increase will lead to a drop in capacity. But too high manganese content can reduce the capacity of a data graph, easy to generate spinel phase, hierarchical structure data. However, if the Ni content is too high, will create mixed with Li + discharge effect, leads to the deterioration of the circulation function and multiplier function, if high nickel data pH is too high, will affect the actual use. Increases with the increase of nickel content, data capacity, but the data of the thermal stability was gradually reduced. Mn can have the effect of stable structure, and Ni can't. With the increase of temperature, the positive Ni in delithium state by tetrahedron position shifted to Li layer, lead to structural collapse and thermal stability problems. Data structure from the bedded salt to spinel structure, and constantly to shape of rock salt, every change is a good oxygen release, accelerated the heat loss of data. For most of the data itself does not produce the precursor, precursor has specialized factories, factory original data from precursor manufacturers purchase data according to the need of sintering, control condition is different, the data function is different also. NCA have serious during the process of charging and discharging gas, leading to cell bulging deformation, cycle and lower place life, bring potential safety hazard to the battery. Therefore, the positive data generally used in the manufacture of the NCA 18650 cylindrical batteries.