CN-122025683-A - Magnesium metal primary battery based on magnesium-sodium ion synergistic effect and preparation method thereof

CN122025683ACN 122025683 ACN122025683 ACN 122025683ACN-122025683-A

Abstract

The invention relates to the technical field of battery preparation, and discloses a magnesium metal primary battery based on magnesium-sodium ion synergistic effect and a preparation method thereof, wherein the magnesium metal primary battery comprises a composite electrolyte and a sodium-magnesium ion mixed ion battery positive plate, the positive plate comprises an active substance, a binder and a current collector, the active substance comprises carbon fluoride, a conductive agent and a binder, the binder comprises PVDF, and the negative electrode reaction of the invention provides high theoretical capacity by magnesium metal; the anode reaction is carried out by electrochemical reaction of monovalent sodium ions, magnesium ions and anode materials, so that the problem of slow reaction kinetics of single magnesium ions is avoided, and therefore, the anode materials with high working voltage and high capacity can be utilized, magnesium ions and sodium ions form an ion transmission loop through electrolyte.

Inventors

WANG DONG
HUANG GUANGSHENG
JIA HONGXING
XU CHAOHE
QU BAIHUA
WANG JINGFENG
PAN FUSHENG

Assignees

重庆新型储能材料与装备研究院

Dates

Publication Date: 20260512
Application Date: 20251231

Claims (8)

1. The magnesium metal primary battery based on the synergistic effect of magnesium and sodium ions comprises a composite electrolyte, a sodium-magnesium ion mole ratio and a positive plate, and is characterized in that the positive plate comprises an active substance, a binder and a current collector, the active substance comprises carbon fluoride, manganese dioxide and a conductive agent, and the binder comprises PVDF.
2. The preparation method of the magnesium metal primary battery based on the synergistic effect of magnesium and sodium ions is based on the magnesium metal organic primary battery system as claimed in claim 1, and is characterized by comprising the following steps: The preparation of composite electrolyte includes dissolving sodium salt and magnesium salt, including Mg [ B (hfip) 4 ] 2 , in organic solvent in inert atmosphere glove box and stirring to dissolve completely to form homogeneous transparent solution; Controlling the mole ratio of Na to Mg ( + ]/[Mg 2+ ) between 1:1 and 10:1, adding Mg 2+ to ensure reversibility of dissolution/deposition of the negative magnesium and maintain the overall ion conductivity, and selecting an ether solvent; Step three, preparing positive plate slurry, namely mixing sodium ion intercalation compound positive electrode materials including carbon fluoride, conductive agents including acetylene black and binders including PVDF into N-methylpyrrolidone NMP according to a certain mass ratio, grinding and stirring to prepare uniform slurry, coating the slurry on a current collector, and drying and punching to prepare the positive plate; and step four, battery assembly, namely taking a metal magnesium sheet or magnesium alloy as a negative electrode, taking the positive electrode sheet prepared in the step two as a positive electrode, adopting a glass fiber diaphragm, injecting the composite electrolyte prepared in the step one, and packaging to obtain the button battery or the soft-package battery.
3. The method for preparing the magnesium metal primary battery based on the synergistic effect of magnesium and sodium ions according to claim 3, wherein the method comprises the following steps: in the first step, the sodium salt includes Na [ B (hfip) 4 ].
4. The method for preparing the magnesium metal primary battery based on the synergistic effect of magnesium and sodium ions according to claim 3, wherein the method comprises the following steps: the organic solvent in step one comprises a DME/THF solvent.
5. The method of claim 3, wherein the solvent in the second step comprises DME, THF, diglyme.
6. The method for producing a magnesium metal primary battery based on the synergistic effect of magnesium and sodium ions as claimed in claim 3, wherein the total salt concentration of the ether solvent in the second step is 0.2 mol/L to 3.0 mol/L.
7. The method for preparing a magnesium metal primary battery based on the synergistic effect of magnesium and sodium ions, as set forth in claim 3, wherein the step three is characterized in that when the slurry is coated on the current collector including the current collector and dried, most of the solvent of the current collector is gently evaporated at the low temperature range of 80-90 ℃, so that the phenomenon that the internal solvent cannot escape due to too fast surface skinning is prevented, and when the slurry is coated on the current collector including the current collector and dried, the residual solvent of the current collector is thoroughly removed at the medium/high temperature range of 100-130 ℃.
8. The method for preparing a magnesium metal primary battery based on the synergistic effect of magnesium and sodium ions as set forth in claim 3, wherein in the third step, when the slurry is coated on a current collector including aluminum foil and dried, most of the solvent in the positive electrode is gently evaporated at 80-90 ℃ in a low temperature section.

Description

Magnesium metal primary battery based on magnesium-sodium ion synergistic effect and preparation method thereof Technical Field The invention relates to the technical field of battery preparation, in particular to a magnesium metal primary battery based on magnesium-sodium ion synergistic effect and a preparation method thereof. Background The magnesium-based primary battery has the advantages of high theoretical capacity, abundant reserve, low cost, good safety and the like because the magnesium-based primary battery takes magnesium as a negative electrode, and is attractive in specific application scenes, however, the traditional magnesium-based primary battery has the technical bottlenecks of low voltage platform and limited capacity of positive electrode materials, in traditional magnesium electrolyte, a plurality of high-capacity positive electrode materials can generate serious electrochemical reaction inertia, namely magnesium ions have very high diffusion energy barrier in the positive electrode materials due to high charge density, slow migration, the actual reversible capacity of the positive electrode materials is far lower than the theoretical capacity of the positive electrode materials, the utilization rate of active substances is low, the voltage platform is low, the discharge voltage platform of the traditional magnesium battery is usually low, the energy density of the battery is directly limited, and the battery does not perform well in the application requiring high working voltage or high energy density. The above serious limitation to further improvement of the performance of the magnesium battery makes the energy density of the magnesium battery difficult to compete with the traditional lithium primary battery or other emerging battery systems, and limits the application potential of the magnesium battery in the fields of high-end portable electronic equipment and the like, and the magnesium battery is particularly expressed in the following aspects: The method comprises the steps of (1) providing high theoretical capacity by magnesium metal in a negative electrode reaction, and enabling a positive electrode reaction to carry out rapid electrochemical reaction by sodium ions and magnesium ions to cause slow magnesium reaction dynamics, (2) enabling the magnesium ions and the sodium ions to form an ion transmission loop by an electrolyte by utilizing a positive electrode material with high working voltage and high capacity, and (3) enabling the high capacity of the magnesium negative electrode and a high voltage platform of the sodium ions and a battery positive electrode material to be difficult to realize rapid embedding dynamics, and enabling higher working voltage and higher discharge capacity to be not realized, so that the energy density of the battery is reduced. Disclosure of Invention The invention aims to provide a magnesium metal primary battery based on the synergistic effect of magnesium and sodium ions and a preparation method thereof, so as to solve the problems in the prior art The method comprises the steps of (1) providing high theoretical capacity by magnesium metal in a negative electrode reaction, and enabling sodium ions and magnesium ions to perform quick electrochemical reaction in a positive electrode reaction to cause slow magnesium reaction dynamics, (2) enabling the magnesium ions and the sodium ions to form an ion transmission loop through electrolyte by utilizing a positive electrode material with high working voltage and high capacity, and (3) enabling the high capacity of the magnesium negative electrode and a high voltage platform of the sodium ions and a battery positive electrode material to be difficult to realize quick embedding dynamics, and enabling higher working voltage and higher discharge capacity to be not realized, so that the energy density of a battery is reduced; Aiming at the problems of insufficient energy density caused by low voltage platform and insufficient capacity exertion of positive electrode materials of the existing magnesium-based primary battery, the invention provides a novel magnesium-sodium mixed ion primary battery and a preparation method thereof. The invention has the core concept of constructing a magnesium-sodium mixed ion primary battery, wherein the battery adopts magnesium metal as a negative electrode, a composite electrolyte capable of reversibly conducting magnesium ions and sodium ions simultaneously, and a compound capable of reacting with sodium ions and magnesium ions simultaneously as a positive electrode material. In order to achieve the aim, the invention provides the technical scheme that the magnesium metal primary battery based on the synergistic effect of magnesium and sodium ions comprises a composite electrolyte, sodium and magnesium ion molar ratio and a positive plate, wherein the positive plate comprises an active substance, a conductive agent, a binder and a current collector, the active substan