Chromite-based lithium primary battery

Abstract

The invention discloses a chromite-based lithium primary battery, and belongs to the technical field of lithium batteries. The anode material of the chromite-based lithium primary battery is chromite. The primary battery adopts the natural chromite mineral as the positive electrode material, so that the cost of the lithium source battery can be greatly reduced, and the primary battery has high energy density.

Description

Technical Field

[0001] The invention relates to a lithium battery, in particular to a chromite-based lithium primary battery, belonging to the field of lithium batteries. Background Art

[0002] With the rapid development of economy and technology, portable, long-lasting, and miniaturized devices are increasingly becoming popular. Especially in cutting-edge fields such as aerospace and military industry, the strategic significance of miniaturized devices and equipment is becoming increasingly important, which puts higher requirements on the current energy storage system in terms of energy density, power, etc. Lithium primary batteries are also called lithium primary batteries, which are batteries assembled with lithium metal as the negative electrode and active materials as the positive electrode. Compared with traditional primary batteries, this type of battery exhibits excellent specific energy and specific capacity. At present, according to the differences in positive electrode materials, it can be divided into lithium-sulfur dioxide batteries, lithium-iron disulfide batteries, lithium-carbon fluoride batteries, etc., but the existing lithium primary batteries are still plagued by problems such as high cost.

[0003] In the prior art, chromium oxide Cr8O 11 Theoretical specific capacity is up to 642 mAh g -1 , the working voltage is 3.0V, and the Fe2O3 material can show a capacity of more than 1000 mAh g within a certain voltage range. -1 Chromite is a natural mineral with the chemical formula (Fe, Mg)Cr2O4. It is widely available and has low cost. However, there has been no report on its direct application in lithium primary batteries. Summary of the invention

[0004] In view of the high cost and other problems of lithium primary batteries in the prior art, the purpose of the present invention is to provide a chromite-based lithium primary battery, which uses natural minerals as positive electrode materials, can greatly reduce the cost of lithium source batteries, and has high energy density.

[0005] In order to achieve the above technical objectives, the present invention provides a chromite-based lithium primary battery, whose positive electrode material is chromite.

[0006] The present invention uses chromite as a natural mineral as the positive electrode material. The chromium and iron elements contained in chromite are both multivalent metal elements and exhibit a higher energy storage capacity.

[0007] As a preferred solution, the chemical formula of the chromite is (Fe, Mg)Cr2O4, and the molar ratio of Mg / Fe is 0.6-1.0. The magnesium-iron ratio of chromite directly affects the stability and electrical conductivity of its lattice. For example, chromite with a high magnesium content tends to have higher chemical inertness and stability, but lower electrical conductivity; while a higher iron content may improve electrical conductivity, and can generally provide more active sites in redox reactions, helping to improve reaction efficiency. A further preferred molar ratio of Mg / Fe in chromite is 0.7-0.9; most preferably 0.8.

[0008] As a preferred solution, the purity of the chromite is not less than 80%. As a more preferred solution, the purity of the chromite is not less than 90%. If the purity of the chromite is too low, impurities will cause a series of side reactions during the battery discharge process, causing the battery to be significantly more dangerous. Therefore, the higher the purity of the chromite, the more conducive it is to its application as a positive electrode material.

[0009] As a preferred solution, the particle size D50 of the chromite is 1-10 μm. If the particle size of the chromite is too small, the compaction density and tap density of the positive electrode material will decrease rapidly, affecting the energy density of the positive electrode material as a whole. If the particle size of the chromite is too large, the electrolyte will not penetrate completely, making it difficult for the particles to react completely, thereby affecting the specific capacity of the material. The particle size D50 of the chromite is further preferably 1-5 μm.

[0010] As a preferred solution, the negative electrode is lithium metal.

[0011] The chromite of the present invention is a conventional commercial product, which is simply crushed and sieved to obtain chromite powder with a certain particle size range, and is used as a positive electrode material for lithium primary batteries.

[0012] The chromite powder of the present invention is assembled into a battery through conventional coating, slicing, assembly and the like, thereby obtaining a lithium primary battery with excellent performance.

[0013] Compared with the prior art, the technical solution of the present invention brings the following beneficial technical effects:

[0014] The present invention uses chromite as the positive electrode material of the lithium primary battery, has high energy density, and improves the performance of the lithium primary battery.

[0015] The present invention uses chromite as the positive electrode material of the lithium primary battery, which effectively reduces the cost.

[0016] The present invention uses chromite as the positive electrode material of the lithium primary battery, and the method for obtaining the lithium primary battery has the advantages of simple operation, short cycle and high economic benefit. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1This is a scanning electron microscope image of the chromite in Example 3.

[0018] Figure 2 This is the element mapping spectrum of the chromite in Example 3; it can be seen from the figure that Fe, Mg, Cr and O are evenly distributed on the surface of the material, and the magnesium-iron ratio is 0.8.

[0019] Figure 3 The XRD spectrum of the chromite in Example 3; the chromite has a good crystal structure.

[0020] Figure 4 This is the XPS characterization of the chromite in Example 3; the XPS results of chromite can reveal the valence information of Cr and Fe elements on its surface; this multi-valence characteristic not only enhances the electron transfer ability, but also promotes the activity of oxygen reduction reaction. DETAILED DESCRIPTION

[0021] The following examples are used to illustrate the present invention, but are not intended to limit the scope of protection of the claims of the present invention.

[0022] The chromite used in the present invention comes from chromite purchased on the market, and the purity of the chromite is not less than 80%.

[0023] In the following specific examples, the chemical formula of chromite is (Fe, Mg)Cr2O4, and the molar ratio of Mg / Fe is 0.8.

[0024] Example 1

[0025] The chromite (purity of 80%) purchased from the market was crushed and sieved to obtain chromite material with a particle size D50 of 5μm, which was then coated and sliced ​​and paired with lithium metal to form a lithium primary battery. Electrochemical performance tests were carried out.

[0026] Coating: The prepared chromite material slurry is evenly coated on the conductive substrate. After coating, the coating sample is placed in a vacuum oven and dried at 100°C to ensure that the solvent is completely volatilized to obtain a uniform electrode film.

[0027] Slicing: The dried electrode film is cut into circular electrode sheets with a diameter of 12 mm using a precision slicer (such as a punch cutter). When slicing, pay attention to the flatness of the edges to avoid affecting subsequent assembly and electrochemical performance.

[0028] Battery assembly: In the glove box, the cut electrode sheets are paired with lithium metal sheets to form button cells (such as CR2032). In the glove box, the electrode sheets, lithium metal sheets, diaphragms (such as Celgard diaphragms) and electrolytes (such as carbonate electrolytes) are placed in the battery case in sequence and packaged into a complete battery using appropriate fixtures and pressure.

[0029] Example 2

[0030] The chromite purchased from the market (purity of 90%) was crushed and sieved to obtain a chromite material with a particle size D50 of 5 μm, which was coated and sliced, and paired with lithium metal to form a lithium primary battery. Electrochemical performance tests were carried out. The specific process of preparing the lithium primary battery is shown in Example 1.

[0031] Example 3

[0032] The chromite purchased from the market (purity of 95%) was crushed and sieved to obtain a chromite material with a particle size D50 of 5 μm, which was coated and sliced, and paired with lithium metal to form a lithium primary battery. Electrochemical performance tests were carried out. The specific process of preparing the lithium primary battery is shown in Example 1.

[0033] Example 4

[0034] The chromite purchased from the market (purity of 95%) was crushed and sieved to obtain a chromite material with a particle size D50 of 10 μm, which was coated and sliced, and paired with lithium metal to form a lithium primary battery. The electrochemical performance test was carried out. The specific process of preparing the lithium primary battery is shown in Example 1.

[0035] Example 5

[0036] The chromite purchased from the market (purity of 95%) was crushed and sieved to obtain a chromite material with a particle size D50 of 1 μm, which was coated and sliced, and paired with lithium metal to form a lithium primary battery. The electrochemical performance test was carried out. The specific process of preparing the lithium primary battery is shown in Example 1.

[0037] 1. Test results: See Table 1:

[0038] The obtained lithium primary battery was heated at 0.1 A g -1 At a current density of , constant current discharge is performed in the voltage range of 3.5~0.01V.

[0039]

Claims

1. A chromite-based lithium primary battery, characterized in that: The positive electrode material is chromite.

2. The chromite-based lithium primary battery according to claim 1, characterized in that: The chemical formula of the chromite is (Fe, Mg)Cr2O4, and the molar ratio of Mg / Fe is 0.6-1.

0.

3. A chromite-based lithium primary battery according to claim 1 or 2, characterized in that: The purity of the chromite ore is not less than 80%.

4. The chromite-based lithium primary battery according to claim 3, characterized in that: The purity of the chromite is not less than 90%.

5. A chromite-based lithium primary battery according to claim 1 or 2, characterized in that: The particle size D50 of the chromite is 1-10 μm.

6. The chromite-based lithium primary battery according to claim 1, characterized in that: The negative electrode is lithium metal.

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