What is the nature of the average voltage of lithium batteries?

What is the nature of the average voltage of a lithium battery? How to improve it? 1. Using the methods of morphology and photoelectron spectroscopy, the Fermi level and the electronic work function of the inferred ion and the change of the accurate value during the operation of the battery are obtained. . 2. By calculating the difference between the ionization potential of several thin film cathode data with different crystal structures and the lithium metal material, the relationship between the ionization potential and the uniform battery voltage is obtained. 3. Through specific experiments and comparisons, the author found that the uniform battery voltage value of almost all positive electrode data is close to the ionization potential difference of the data, but the defects of the positive electrode data will cause relatively large errors. What is the nature of the uniform voltage in lithium? How? (Research background) Generally speaking, the higher the specific volume of the electrode, the higher the voltage of the uniform battery may be, which is undoubtedly beneficial to the improvement of battery energy density. At the same time, the uniform battery voltage is determined by the enthalpy of the lithium ion exchange reaction, including the intercalation and stripping of lithium ions on the active electrode data. Regarding ordinary positive data, the electrode reaction seems to be a redox reaction at first glance, but this view does not take into account the guessed interaction between electrons and ions. Due to these mutual uses, the electronic state of the reactive transition metal ion depends on the degree of insertion. What is the nature of uniform voltage in lithium? How? In this article, Professor Wolfram Jaegermann of Darmstadt University of Technology, Germany, due to lack of knowledge of traditional battery uniform voltage analysis methods, proposed a new method to analyze battery uniform electrode potential . As shown in the figure, it is a schematic diagram of the Fermi level and the electronic structure density (DOS) of the electrode. It can be seen that under normal circumstances, the Fermi level of the positive electrode data is located in the tm-3d lead-out band and moves with the change of the charge state, and its displacement is related to the corresponding displacement of the electron chemical potential. However, the information obtained only from this graph is incomplete, because it does not take into account the difference in the chemical potential of lithium ions between metallic lithium and other negative electrodes. In order to more accurately reflect the electrode voltage of the lithium battery, it can be indicated by the change of Gibbs free energy ΔG that maybe the difference between the positive and negative lithium chemical potentials (μμCLi, ALi) indicates: What is the nature of the uniform voltage in lithium? ? In the above formula, z represents the charge transfer between the electrodes (here 1), and F represents the Faraday constant. The form can be divided into two parts: the chemical potential of lithium, the electronic chemical potential ΔΔμμe and the ionic chemical potential Li+, which further describe the positive and negative Gibbs free energy changes, and their exchange with electrons and ions. It is generally believed that electrons play a dominant role. For example, in the olivine hypothesis, replacing the transition metal ions with a higher ionization potential can obtain a higher uniform voltage. This conclusion is supported by many reports (j. Electrochem). Soc. , 144, 1188 (1997); Periodicals. Chemistry. B, 108, 16093 (2004).). In order to understand the basic process of electron and ion exchange in the electrode and its influence on battery performance, Ceder et al. developed the first first-principles calculation (Phys). Rev. B, 56(3), 1354 (1997).). But so far, no experiments have been able to describe the effect of electron-ion interaction on battery voltage. The electrochemical potential of an electron can be determined by the difference between the Fermi level of the solid and the work function of the electron. Therefore, in this article, the author looks like science, photoelectron spectroscopy is used to obtain information and guess the Fermi level ion electron work function and accurate value to change the operation of the battery, the calculation of the ionization potential and several crystal structure differences The positive data with the lithium metal film found the relationship between the uniform ionization potential and the battery voltage. 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 article: Solid-state batteries will become a substitute for ternary batteries