CN-121983606-A - Electron supplementing agent, preparation method, alkali metal battery and application

CN121983606ACN 121983606 ACN121983606 ACN 121983606ACN-121983606-A

Abstract

The invention belongs to the technical field of electrochemical energy storage batteries, and provides an electron supplementing agent, a preparation method, an alkali metal battery and application. The electron-supplementing agent is a solution of a stable complex formed by solvated electrons and electron-deficient organic molecules, the electron-deficient organic molecules are compounds which have a central polycyclic aromatic hydrocarbon structure and are substituted by strong electron-withdrawing groups at symmetrical positions of the polycyclic aromatic hydrocarbon, and the strong electron-withdrawing groups enable the central polycyclic aromatic hydrocarbon to form an electron-deficient central ring structure, so that one solvated electron can be captured and stabilized, and an e ‑ @electron-deficient organic molecule complex is formed. The preparation method of the electron supplementing agent is simple, is easy for large-scale production, and can obviously improve the performance of the primary battery. The application of the stabilized solvated electrons is not limited to primary batteries, and can be expanded to the fields of secondary batteries, photoelectric catalytic conversion, synthetic chemistry, pollutant degradation and the like, thereby having great application value.

Inventors

YAN ZHENHUA
HUANG WEIWEI
LI HAIXIA
FENG XIN
CHEN JUN
LI YIXIN
Ni Youxuan
ZHANG KAI
XIE WEIWEI
CHENG WEICHAO
Lv Linxin

Assignees

南开大学

Dates

Publication Date: 20260505
Application Date: 20260403

Claims (10)

1. The electron-supplementing agent is a solution of a stable complex formed by solvated electrons and electron-deficient organic molecules, wherein the electron-deficient organic molecules are compounds which have a central polycyclic aromatic hydrocarbon structure and are substituted by strong electron-withdrawing groups at symmetrical positions of the polycyclic aromatic hydrocarbon, and the strong electron-withdrawing groups enable the central polycyclic aromatic hydrocarbon to form an electron-deficient central ring structure, so that one solvated electron can be captured and stabilized, and an e - @electron-deficient organic molecule complex is formed.
2. The electron-supplementing agent according to claim 1, wherein the electron-deficient organic molecule is tetranitropyrene.
3. A method of preparing the electron-supplementing agent according to claim 1 or 2, comprising the steps of: s1, dispersing or dissolving the electron-deficient organic molecules in a solvent or electrolyte with moderate polarity to obtain a suspension; S2, adding alkali metal into the suspension in the step S1, and stirring and reacting until a solution with uniform and stable color is formed; and S3, standing the solution obtained in the step S2, and taking supernatant to obtain the electron supplementing agent.
4. The method according to claim 3, wherein in step S1, the solvent having a moderate polarity is one or more selected from the group consisting of ethylene glycol dimethyl ether, tetrahydrofuran, and 1, 2-dimethoxypropane.
5. A method of preparation according to claim 3, wherein the salt in the electrolyte is a lithium salt or a sodium salt; the lithium salt is selected from one or more of lithium perchlorate, lithium hexafluorophosphate, lithium difluorosulfimide and lithium tetrafluoroborate; The sodium salt is one or more selected from sodium perchlorate, sodium hexafluorophosphate, sodium trifluoromethane sulfonate and sodium tetrafluoroborate.
6. The method according to claim 3, wherein the solvent in the electrolyte is selected from the group consisting of an ether solvent and a mixed solvent of an ether solvent and a carbonate solvent; Wherein the ether solvent is selected from one or more than two of ethylene glycol dimethyl ether, tetrahydrofuran, 1, 2-dimethoxypropane and 1, 4-dioxane; The carbonate solvent is one or more selected from ethylene carbonate, propylene carbonate, dimethyl carbonate and diethyl carbonate.
7. The method according to claim 3, wherein in the step S2, the alkali metal is lithium, sodium or potassium, the molar ratio of the electron-deficient organic molecule to the alkali metal is (1:5000) - (1:10000), and the reaction is carried out at 20-30 ℃.
8. An alkali metal cell comprising a negative electrode, a positive electrode, a separator and an electrolyte, wherein the electrolyte comprises an effective amount of the electron-supplementing agent of claim 1 or 2 or the electron-supplementing agent prepared by the method of any one of claims 3-7.
9. The alkali metal cell according to claim 8, wherein the negative electrode is lithium, sodium or potassium, the active material of the positive electrode is an inorganic positive electrode material or an organic positive electrode material, the inorganic positive electrode material is one or more selected from manganese dioxide, carbon fluoride, ferrous sulfide and vanadium pentoxide, the organic positive electrode material is one or more selected from mono-nitropyrene, dinitropyrene, tri-nitropyrene, anthraquinone and 1, 5-dinitroanthraquinone, and the alkali metal cell is a secondary cell or a primary cell.
10. The use of an electron-supplementing agent according to claim 1 or 2 for alleviating battery voltage polarization, improving rate capability, and promoting deep reduction of a positive electrode material.

Description

Electron supplementing agent, preparation method, alkali metal battery and application Technical Field The invention belongs to the technical field of electrochemical energy storage batteries, and particularly relates to an electron supplementing agent, a preparation method, an alkali metal battery and application. Background The alkali metal battery, especially the lithium primary battery, is an important class of high-energy density power supply, has the outstanding advantages of high energy density, long storage life, low self-discharge rate and the like, and has irreplaceable functions in the fields of implantable medical equipment, aerospace systems, remote sensing equipment and the like which need long-term maintenance-free operation. The performance of such batteries depends on the positive electrode material thereof. Existing positive electrode materials include inorganic materials represented by carbon fluoride (CF x), manganese dioxide (MnO 2) which have been successfully commercialized, and recently reported organic compounds having a multiple electron reduction mechanism. However, the increasingly severe working environment and complex functional indexes place higher demands on the energy density and rate capability of lithium primary batteries. Currently, a fluorocarbon anode is generally limited by voltage hysteresis and poor rate capability caused by problems of slow reaction kinetics, low conductive byproducts blocking ion transmission and the like. The use of small organic molecular materials is limited by high solubility and limited degree of reduction and does not fully highlight their high energy density advantages. Solvated electrons are the smallest anions and the strongest reducing particles in nature and play a key role in radiochemical, photochemical and biochemical processes. The solvated electrons are used as the most basic and efficient reducing agent in the chemical field, and have extremely broad application prospects in organic synthesis, biomedical engineering, environmental wastewater treatment and the like. Solvated electrons are generally very susceptible to property transients and deactivation under radiolysis conditions, which presents a great challenge for the investigation of solvated electrons and their controllable use in electrochemical systems such as batteries. How to realize the long-term stable existence of solvated electrons in a practical battery system and exert the advantage of rapid electron transfer of the solvated electrons is a technical bottleneck which is not broken through in the field. In the prior art, for example, chinese patent CN119864417A discloses that polynitropyrene is used as a positive electrode active material of a primary battery. The technology focuses on improving the specific capacity and energy density of the organic material by introducing a nitro functional group, increasing a conjugated system and carbon load and adding a proton donor through molecular design. The technical idea is to take nitropyrene as an energy storage main body all the time, and the problem of the commonality dynamics of the battery system cannot be solved. It is not suggested that nitropyrene materials can be used to capture and stabilize highly active solvated electrons and change their function from energy storage to conduction. Disclosure of Invention Aiming at the technical problems of low electron conductivity, slow reaction kinetics, limited reduction degree of active substances and the like in the field of alkali metal batteries, in particular primary batteries in the prior art, the invention aims to provide a brand-new technical solution, namely an electron supplementing agent, a preparation method, an alkali metal battery and application. The invention discovers that a class of organic molecules with specific electron-deficient structures, in particular tetranitropyrene, the strong electron-pulling groups at symmetrical positions can effectively delocalize electrons in the center of pyrene nucleus to form a center ring structure with insufficient electrons, and an ideal carrier is provided for stabilizing solvated electrons, so that the solvated electrons can maintain a stable state in electrolyte, timely supplement and conduct electrons in the discharging process of a battery, and the strong reducing capability can also promote the effective utilization of organic anode materials, improve the energy density and reduce voltage polarization. The technical scheme of the invention is as follows: The first aspect of the present invention provides an electron-supplementing agent for an alkali metal cell, wherein the electron-supplementing agent is a solution of a stable complex formed by solvated electrons and electron-deficient organic molecules, the electron-deficient organic molecules are compounds which have a central polycyclic aromatic hydrocarbon structure and are substituted by strong electron-withdrawing groups at symmetrical positions of the poly