The influence of battery shell alloy content on battery performance

Study the influence of alloy content on battery performance. Lithium-ion battery is a battery with poor lithium ion concentration. During charging and discharging, Li+ is de-intercalated between the positive and negative electrodes. In the Li+de-embedded process (x decreases from 1 to 0.4), the interlayer spacing increases from 0.465nm to 0.485nm, and the volume of the positive electrode increases. During the Li+ graphite embedding process, the graphite layer spacing d002 was increased from 0.3454nm to 0.3706nm (LiC6), and the volume of the cathode increased [10]. Lithium ions undergo electromigration under the use of an electric field. When the lithium ion migration number is constant, the lithium ion migration flow changes with the change of the internal geometry of the battery. The shell expands, the space between the positive electrode and the negative electrode increases, the lithium ion migration speed slows down, the migration is difficult, and the conductivity of the solution changes qualitatively [11]. 053450 3 The internal volume change of the battery is small in resistance to the lower shell wall, and the mobility of lithium ions is greater than 0534501-0534502, and the corresponding solution conductivity is larger, which can be reflected in the internal resistance of the battery. The internal resistance of the 053450a3 battery is slightly smaller than the other two specifications. The internal resistance is small, the irreversible specific capacity loss is small, the battery release capacity is large, and the cycle life is correspondingly high. This is why the specific discharge capacity and cycle life of the 053450A3 battery are slightly higher than those of the 053450A1 and 053450A2. It is worth mentioning that the discharging platforms of the three battery specifications are not too different. The stability and protective layer of the passivation film on the electrolyte and electrode surface of the lithium ion battery during the first discharge (solid electrolyte system face, hereinafter referred to as SEI film) [6], the formation of the passivation film, the electrode and battery performance and irreversible specific capacity loss play a role Important use. The electrolyte can be separated from the electrode, eliminating (or reducing) the solvent and anions in the electrolyte from entering the electrode, preventing the co-intercalation of solvent molecules, allowing Li+ to intercalate and deintercalate, and protect the electrode [7]. During the formation of SEI film, HF, short-chain r-h, CO2, CO and other gases are generated [8], and the electrolyte solvent decomposes to generate gas r-h, etc. [9]. After the SEI film is formed, the presence of water decomposes LiPF6 into HF gas [10]. The appearance of these gases will increase the internal pressure of the battery, thereby gradually increasing the tendency of the battery casing to expand outward. The resistance of the shell to the side drum is different, and the corresponding battery performance is also different. According to section 1.1, the expansion coefficient of 053450a3 relative to the original shell thickness is 1.018, which is lower than 053450a1 and 053450a2. The expansion coefficient is small, the expansion of the battery casing is small, and the thickness of the battery is also small. The thickness of the finished battery of 053450a3 is smaller than that of the other two specifications. The important factor controlling the expansion of the battery casing is the content of copper and magnesium alloy in the casing. The alloy content of the shell of 053450a3 is slightly higher than the other two specifications, especially Mg. In the design of the battery, the basic guarantee of the tightness of the core into the casing (also known as the assembly ratio of the battery) is 85%. The airtightness of the battery is generally controlled at 80%~90%[5]. Under the same external conditions, the internal water content of the three groups of experimental batteries is basically the same, that is, the internal pressure of the three groups of experimental batteries is basically the same. Experimental data shows that the 053450a3 battery case has higher pressure resistance and smaller side drums, while the 053450a1 and 053450a2 battery cases have lower pressure resistance and larger side drums. How to improve the safety of lithium-ion batteries and improve the thermal stability of electrode materials The safety problems of ion batteries are directly caused by unsafe electrolytes, but the fundamental reason is the low stability of the battery itself and the occurrence of thermal runaway. In addition to the thermal stability of the electrolyte, the thermal stability of the electrode material is one of the most important reasons for thermal runaway. Therefore, improving the thermal stability of the electrode material is an important part of improving the safety of the battery. Thermal stability and thermal stability statement: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete the previous article: Analysis of the classification and application of lithium-ion batteries