A chromite-based lithium primary battery

Abstract

The application discloses a chromite-based lithium primary battery and belongs to the technical field of lithium batteries. A positive electrode material of the chromite-based lithium primary battery is chromite. The primary battery adopts natural chromite minerals as the positive electrode material, can greatly reduce the cost of lithium source batteries, and has high energy density.

Description

Technical Field

[0001] This invention relates to a lithium battery, and more particularly to a chromite-based lithium primary battery, belonging to the field of lithium batteries. Background Technology

[0002] With rapid economic and technological development, portable, long-lasting, and miniaturized devices are increasingly sought after. Especially in cutting-edge fields such as aerospace and military, the strategic significance of miniaturized devices is growing, placing higher demands on current energy storage systems in terms of energy density and power. Lithium primary batteries, also known as lithium-ion batteries, are batteries assembled using lithium metal as the negative electrode and active materials as the positive electrode. Compared to traditional primary batteries, these batteries exhibit superior specific energy and specific capacity. Currently, based on differences in the positive electrode material, they can be divided into lithium-sulfur dioxide batteries, lithium-iron disulfide batteries, lithium-carbon fluoride batteries, etc., but existing lithium primary batteries are still hampered by high costs.

[0003] In the prior art, there are reports of chromium oxide Cr8O 11 The theoretical specific capacity is as high as 642 mAh g -1 With an operating voltage of 3.0V, the ferric oxide (Fe2O3) material can exhibit a performance greater than 1000 mAh g⁻¹ within a certain voltage range. -1 The capacity. Chromite, as a natural mineral with the chemical formula (Fe, Mg)Cr2O4, is widely available and inexpensive, but so far there have been no reports of its direct application in lithium primary batteries. Summary of the Invention

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

[0005] To achieve the above-mentioned technical objectives, the present invention provides a chromite-based lithium primary battery, wherein the positive electrode material is chromite.

[0006] This invention uses chromite as a natural mineral as the cathode material. The chromium and iron elements contained in it are both multivalent metal elements, exhibiting a high energy storage capacity.

[0007] As a preferred embodiment, the chromite has the chemical formula (Fe, Mg)Cr₂O₄, with a Mg / Fe molar ratio of 0.6 to 1.0. The Mg / Fe ratio of chromite directly affects its lattice stability and electrical conductivity. For example, chromite with high magnesium content often exhibits higher chemical inertness and stability, but lower electrical conductivity; while higher iron content may improve electrical conductivity and typically provides more active sites in redox reactions, thus contributing to increased reaction efficiency. Further preferred chromite has a Mg / Fe molar ratio of 0.7 to 0.9; most preferably, it is 0.8.

[0008] As a preferred embodiment, the chromite has a purity of not less than 80%. As a more preferred embodiment, the chromite has a purity of not less than 90%. If the purity of the chromite is too low, impurities will trigger a series of side reactions during battery discharge, significantly increasing the battery's hazard. Therefore, higher purity chromite is more advantageous for its application as a cathode material.

[0009] As a preferred embodiment, the particle size D50 of the chromite is 1~10μm. If the particle size of the chromite is too small, it will cause a rapid decrease in the compaction density and tap density of the cathode material, thus affecting the overall energy density of the cathode material. Conversely, if the particle size of the chromite is too large, it will lead to incomplete electrolyte penetration, 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 1~5μm.

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

[0011] The chromite used in this invention is a conventional commercially available product. It is simply crushed and sieved to obtain chromite powder with a certain particle size range, which is then used as a positive electrode material for lithium primary batteries.

[0012] The chromite powder of the present invention is used for battery assembly through conventional methods such as coating, slicing, and assembly to obtain high-performance lithium primary batteries.

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

[0014] This invention uses chromite as the positive electrode material for lithium primary batteries, which has high energy density and improves the performance of lithium primary batteries.

[0015] This invention uses chromite as the positive electrode material for lithium primary batteries, effectively reducing costs.

[0016] This invention uses chromite as the positive electrode material for lithium primary batteries, and the method for obtaining lithium primary batteries is simple to operate, has a short cycle, and high economic benefits. Attached Figure Description

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

[0018] Figure 2 The image shows the elemental mapping spectrum of chromite in Example 3. As can be seen from the image, Fe, Mg, Cr and O are evenly distributed on the surface of the material, and the magnesium-to-iron ratio is 0.8.

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

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

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

[0022] The chromite used in this invention is purchased from the market and has a purity of 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] Chromite (80% purity) purchased from the market was crushed and screened to obtain chromite material with a particle size D50 of 5 μm. After coating and slicing, it was paired with lithium metal to form a lithium primary battery. Electrochemical performance testing was then conducted.

[0026] Coating: The prepared chromite slurry is uniformly coated onto the conductive substrate. After coating, the coated sample is placed in a vacuum oven and dried at 100°C to ensure complete solvent evaporation and obtain a uniform electrode film.

[0027] Slicing: After drying, the electrode film is sliced ​​into circular electrode sheets with a diameter of 12 mm using a precision slicer (such as a punch cutter). Care should be taken to ensure the edges are smooth during slicing to avoid affecting subsequent assembly and electrochemical performance.

[0028] Battery assembly: Inside the glove box, the cut electrode sheets are paired with lithium metal sheets and assembled into coin cells (such as the CR2032 type). Inside the glove box, the electrode sheets, lithium metal sheets, separator (such as Celgard separator), and electrolyte (such as carbonate electrolyte) are placed in sequence in the battery case, and sealed into a complete battery using appropriate clamps and pressure.

[0029] Example 2

[0030] Chromite (90% purity) purchased from the market was crushed and sieved to obtain chromite material with a particle size D50 of 5 μm. This material was then coated, sliced, and paired with lithium metal to form a lithium primary battery. Electrochemical performance tests were conducted. For the specific process of preparing the lithium primary battery, please refer to Example 1.

[0031] Example 3

[0032] Chromite (95% purity) purchased from the market was crushed and sieved to obtain chromite material with a particle size D50 of 5 μm. This material was then coated, sliced, and paired with lithium metal to form a lithium primary battery. Electrochemical performance tests were conducted. For the specific process of preparing the lithium primary battery, please refer to Example 1.

[0033] Example 4

[0034] Chromite (95% purity) purchased from the market was crushed and sieved to obtain chromite material with a particle size D50 of 10 μm. This material was then coated, sliced, and paired with lithium metal to form a lithium primary battery. Electrochemical performance tests were conducted. For the specific process of preparing the lithium primary battery, please refer to Example 1.

[0035] Example 5

[0036] Chromite (95% purity) purchased from the market was crushed and sieved to obtain chromite material with a particle size D50 of 1 μm. This material was then coated, sliced, and paired with lithium metal to form a lithium primary battery. Electrochemical performance tests were conducted. For the specific process of preparing the lithium primary battery, please refer to Example 1.

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

[0038] The obtained lithium primary battery was subjected to a temperature of 0.1 A g. -1 Under a current density of 3.5 to 0.01V, constant current discharge is performed.

[0039]

Claims

1. A chromite-based lithium primary battery, characterized in that: The cathode material is chromite; the chemical formula of the chromite is (Fe, Mg)Cr2O4, and the molar ratio of Mg / Fe is 0.6~1.

0.

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

3. A chromite-based lithium primary battery according to claim 2, characterized in that: The purity of the chromite is not less than 90%.

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

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

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