What are the effects of positive electrode materials on lithium batteries
The anode material for lithium batteries is one of the first conditions for determining the life of lithium batteries. Currently, the anode materials for commercial lithium batteries are LiCoO2, spinel-like LiMn2O4, malachite-like LFP, etc.
In recent ten years, although the battery anode materials of lithium batteries are all lithium connected hydroxides, the melting of transition elements has been a difficult problem, especially the LiMn2O4 spinel positive stage. In the long period or the whole process of high temperature storage, the volume usually shows a significant attenuation coefficient. Among them, the fusion of manganese ions is one of the key reasons, especially when the acid attack of LiMn2O4 caused by adverse reactions, manganese ions can be dissolved in the electrolyte of lithium battery.
The oxidation of electrolyte solution into hydroxide ion and hydrochloric acid when the working voltage is too high accelerates the disproportionation reaction of manganese, and the solubility expands with the transformation of the phase difference of height and height in the whole process of the circulation system. When manganese ions dissolve in the lithium battery electrolyte, several relative conditions occur, including structural instability, active material outflow, resistor enlargement, etc. Lithium iron phosphate has spinel structure, so it is necessary to remove the embedded lithium ion battery. However, Mn in raw materials can be dissolved in lithium battery electrolyte at high temperature, resulting in irreversible damage to the working ability of lithium battery electrolyte. In addition, when the high temperature charge and discharge, the raw material easy to produce JAHn-teller utility, so that the crystal structure of the specific raw material is damaged, so that the battery power attenuation coefficient is accelerated.
LFP is a malachite-like structure with very good reliability and safety coefficient. The external diffusion characteristic impedance is slightly increased, and the ohmic characteristic impedance and electrochemical corrosion characteristic impedance both increase. Among them, the photoelectric catalytic characteristic impedance has a relatively large growth range. The key to capacitor depletion is the adverse reaction of the electric stage and lithium battery electrolyte, in which the specific lithium depletion is the key cause of capacitor depletion, and the SEI will cause capacitor depletion due to the negative stage volume transformation in the whole cycle system.
Cobalt acid lithium is the slice layer structure, it can ensure the Li + embedded and put off the level and its structure change during the whole process, under the standard of polymer batteries battery will continue to harm the service life of lithium-ion battery, charging and discharging rate of ascension causes Li + and the blending of Co molecules, causing part of LiCoO2 crystal structure into a cubic crystal structure, from the six parties battery cathode material structure attenuation coefficient caused by the growth of volume. With the application of lithium batteries, the total number of lithium ion batteries in the electrolyte of lithium battery decreases slowly. In addition, due to the reduction of convective heat transfer capacity of lithium ion battery, the battery power attenuation coefficient is also caused. The outflow of active lithium-ion batteries is mainly due to the constant consumption of the electrolyte of lithium batteries and active substances with positive and negative properties in the whole cycle system.
With the increase of the cycle frequency, the positive stage characteristic impedance increased significantly while the negative stage characteristic impedance did not change significantly, while the negative stage volume decreased significantly while the positive stage characteristic impedance did not change significantly. Due to the increase of the characteristic impedance of the positive stage and the damage of the negative stage volume, the battery power of the circulatory system is reduced during the whole process.
Due to its large volume specific energy, high quality specific energy, high working standard voltage, low efficiency of life, and no memory, lithium battery has been widely used in consumer electronic equipment. With the expansion of its main USES, lithium battery has clearly put forward higher provisions on its characteristics. Under high temperature, the volume attenuation coefficient of lithium battery is faster, the low multiple characteristic is poor, the high life speed of lithium battery and other problems seriously hinder its application.
Through the introduction of the impact of anode materials on the life of lithium batteries, in fact, there are many reasons that affect the life of lithium batteries, such as product quality problems, improper use, which we need to pay attention to.