Analyses the influencing factors of lithium battery internal resistance

Source: 2020 - 03 - 24 12:58 hits: time why lithium battery internal resistance? Lithium battery internal resistance, static resistance and working resistance is often different. In different environment, the internal resistance also changes with the change in temperature. What are the factors influencing lithium battery internal resistance? 1. Lithium battery operation why the lithium battery internal resistance? As is shown above, is a physical model of lithium ion battery charging and discharging process. Blue arrows indicate the charging, the red arrows indicate discharge. Blue and green grid structure is data, black is negative data. The current mainstream of lithium ion battery, generally by the positive data type named, lithium iron phosphate, lithium manganese phosphate is the positive data types; The cathode graphite materials; The positive collecting fluid aluminum foil, negative collecting fluid copper foil. Let us to discharge as an example to describe the physical process of lithium battery discharge. After connection of external load, on the outside of the cell body form the current path. Due to the potential difference between the positive and negative, the primary electron flow near the cathode and external conductor is moved to the anode. Around the cathode of lithium ion concentration increased. From the cathode through an external circuit into the positive, and close to the anode of lithium ion, embedding the positive data. Near the anode of lithium ion concentration decreased. The difference between the positive and negative concentration of lithium ion. This completes the first step in the battery discharge process. With lithium ions from the negative ion concentration in the ascension, space appears near the cathode. Negative data in the lithium ions break away from the cathode and into the electrolyte. A large number of lithium ions from the electrolyte through the diaphragm, self to the positive movement. With lithium ion and electron with lithium ion bonding form, through an external circuit to the anode. According to the needs of load began to discharge battery. Instead of charging is discharge process. Using the same digging, moving, buried three stages. However, promote the process of the development of the power from the charger, and the movement direction of the ion from the positive to negative. I don't speak in detail here. 2, lithium battery internal resistance to understand the operation process of lithium-ion batteries, and understand the process of block elements, which constitute a lithium battery internal resistance. The battery internal resistance by the ohmic resistance and the polarization resistance. In the case of temperature stability, ohmic resistance is stable, and the polarization resistance will change as the factors influencing the level of polarization. Ohmic resistance is mainly composed of data electrode, electrolyte, the membrane resistance and contact resistance and so on various parts, such as collecting fluid connection with a ear. It is related to the size of the battery, structure and connection way. Polarization resistance is generated when the load current and battery is stop charged ions in the sum total of all kinds of trends to the destination. Polarization resistance can be divided into the electrochemical polarization and concentration polarization. When the electrolyte in the electrochemical reaction rate cannot achieve electronic movement speed, electrochemical polarization can be built up. When lithium-ion embedded in the positive and negative data, and more than lithium ion speed slow speed into the electrode, will form the concentration polarization. 3. The influence factors of lithium battery internal resistance is derived from the above process can be the influence factors of battery internal resistance. 3. 1 additional element temperature and environmental temperature is one of the important factors affecting a variety of resistance, especially lithium battery, because temperature influence the activity of the electrochemical data, directly determines the electrochemical reaction and the speed of the ion movement.