Lithium titanate battery principle and composition structure analysis

Lithium titanate batteries are composed of positive and negative plates (the active material of the positive electrode is ternary lithium, and the negative electrode is lithium titanate), a separator, an electrolyte, a tab, and a stainless steel (aluminum alloy) casing. The positive and negative plates are the electrochemical reaction area, the diaphragm and the electrolyte supply the transmission channel of Li+, and the tabs play the role of guiding current. When the battery is charged, Li+ migrates from the ternary lithium material to the surface of the crystal, is removed from the positive plate material, enters the electrolyte under the use of electric field force, passes through the diaphragm, and then migrates to the negative electrode lithium titanate crystal through the electrolyte. The surface is then embedded in the negative lithium titanate spinel structure material. At the same time, electrons flow through the aluminum foil of the positive electrode, flow through the tab, battery pole, load, negative pole, and negative tab to the aluminum foil electrode of the negative pole, and then flow to the lithium titanate negative pole through the conductor to balance the charge. When the battery is discharged, Li+ is deintercalated from the lithium titanate spinel structure material, enters the electrolyte, passes through the diaphragm, and then migrates to the surface of the ternary lithium crystal through the electrolyte, and then re-embeds in the ternary lithium material. At the same time, electrons flow to the aluminum foil electrode of the negative electrode through the conductor, and flow to the aluminum foil electrode of the battery positive electrode through the tab, battery negative pole, load, positive pole, and positive tab, and then flow to the ternary lithium positive pole through the conductor. To balance the charge. It can be seen that the basic principle of a lithium titanate battery is that during the process of charging and discharging, the corresponding lithium ions are intercalated back and forth between the positive and negative electrodes to complete the charging and discharging of the battery and the power supply to the load. The charging and discharging diagram of the lithium titanate battery is shown in the figure. When the battery is charged, the positive electrode loses electrons, and lithium ions are extracted and inserted into the negative electrode; while the negative electrode is inserted into lithium ions, electrons become lithium-rich state at the same time. The process of discharging is just the opposite. In the Li+ intercalation or deintercalation reaction process, lithium titanate (Li4TI5O12) is an ideal intercalation electrode material. Li+ intercalation and deintercalation have almost no effect on the material structure, so it is called a zero-strain material, thus ensuring Its good cycle performance. There are two different molecular structures of lithium titanate: Li7TI5O12 and Li4TI5O12. Both the crystal structure of Li7TI5O12 and the crystal structure of Li4Ti5O12 are spinel structures, and the change of the lattice constant is very small, and the volume change is also very small. It can guard against the back and forth expansion and contraction of the electrode material during the charge and discharge cycle to cause structural damage, thereby improving the cycle performance and service life of the electrode, reducing the capacity attenuation caused by the increase in the number of cycles, and making lithium titanate have excellent cycles performance. The structure of the lithium titanate battery constitutes the positive electrode: lithium iron phosphate, lithium manganate or ternary material, lithium nickel manganate. Negative electrode: lithium titanate material. Separator: Lithium battery separator with carbon as the negative electrode. Electrolyte: Lithium battery electrolyte with carbon as the negative electrode. Battery case: Lithium battery case with carbon as negative electrode. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: Analysis of the advantages and disadvantages of ternary lithium battery packs