Novel rock salt phase high-entropy oxide negative electrode material and preparation method and application thereof

Abstract

The invention discloses a novel rock salt phase high-entropy oxide negative electrode material and a preparation method and application thereof, and belongs to the field of energy storage materials. The molecular formula of the rock salt phase high-entropy oxide negative electrode material is (M0. 2Co0. 2Ni0. 2Cu0. 2Zn0. 2) O, wherein M is Li or Na; the preparation method comprises the following steps: weighing five kinds of metal oxide powder according to the equal molar ratio of five kinds of metal, putting the powder into a ball milling tank for wet milling to obtain precursor slurry, heating and drying the precursor slurry, calcining the precursor slurry, cooling the precursor slurry along with a furnace to obtain (M0. 2Co0. 2Ni0. 2Cu0. 2Zn0. 2) O high-entropy oxide powder, mixing the (M0. 2Co0. 2Ni0. 2Cu0. 2Zn0. 2) O high-entropy oxide powder with a conductive agent and a binder, grinding the mixture to form slurry, uniformly coating a copper foil with the slurry, and drying the slurry to obtain the high-entropy oxide. And vacuum heating and drying. The rock salt phase high-entropy oxide is stable in structure, low-valence Li < + > and Na < + > can cause charge compensation of an electrode material, more oxygen vacancies are formed, and then the electrochemical performance is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of energy storage materials, and particularly relates to a novel rock salt phase high-entropy oxide negative electrode material and a preparation method and application thereof. BACKGROUND

[0002] With the development of energy storage devices, the energy density and power density requirements of lithium ion batteries for electrode materials are becoming higher and higher, and the commercial graphite negative electrode has been difficult to meet the high performance requirements of lithium ion batteries. Therefore, developing high-capacity negative electrode materials is the key to improving the energy density of lithium ion batteries. Transition metal oxides have the advantages of high specific capacity and have been widely concerned as negative electrode materials for lithium ion batteries; however, due to their low electrical conductivity, poor ion diffusion ability, and large volume expansion during charge / discharge, which leads to poor electrochemical performance, which has become the main obstacle to their application as negative electrode materials.

[0003] Recently, high-entropy oxides, as a novel multi-metal oxide, have excellent thermodynamic / kinetic stability and entropy stabilization effect due to adjustable element composition, and have higher electronic conductivity and multiple electrochemically active components compared with transition metal oxides. Therefore, high-entropy oxides have become one of the popular candidate materials to replace traditional graphite anode materials.

[0004] Although high-entropy oxide negative electrode materials exhibit great potential in performance, existing researches on rock salt phase high-entropy oxides (Mg 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )O, Chinese patent CN107994228A discloses a lithium ion battery five-element high-entropy oxide nano film and its preparation and application. However, this method has the disadvantages of complex preparation process, high energy consumption, etc. For the research on the application of high-entropy oxides in lithium ion battery negative electrode materials, Chinese patent CN110190259A discloses a preparation method of nano high-entropy oxides and a lithium ion battery negative electrode material. At a current density of 100 mA / g, the discharge specific capacity is maintained between 329.7 mAh / g and 413.6 mAh / g after 100 cycles. The material prepared by the above existing technology has the problems of complex preparation process and low specific capacity. Improving the electrochemical performance of high-entropy oxide negative electrodes is still a research focus. Therefore, developing high-entropy oxide negative electrode materials with high specific capacity and excellent cycle performance has become a technical problem to be solved. SUMMARY

[0005] In view of the problems existing in the prior art, the present application aims to provide a novel rock salt phase high-entropy oxide negative electrode material and a preparation method and application thereof, wherein low-valence lithium ions or sodium ions are introduced by a high-temperature solid phase method to replace magnesium ions in the existing rock salt phase high-entropy oxide (Mg 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )O, forming a rock salt phase high-entropy oxide with a completely new composition, which can be synthesized at a high throughput and used as a battery negative electrode material, has a high specific capacity and excellent cycle performance.

[0006] The purpose of the present application is achieved by the following technical solutions.

[0007] In a first aspect, the present application provides a novel rock salt phase high-entropy oxide negative electrode material, which has a molecular formula of (M 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )O, wherein M is Li or Na.

[0008] In a second aspect, the present application provides a preparation method of a novel rock salt phase high-entropy oxide negative electrode material, comprising the following steps:

[0009] (1) five kinds of metal oxide powders are respectively taken according to the equimolar ratio of the five metals in (M 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )O;

[0010] (2) the five kinds of metal oxide powders are placed in a ball mill jar, ball milling beads and a liquid medium are added, and the ball mill parameters are set for wet milling;

[0011] (3) the precursor slurry after ball milling is heated and dried to obtain a precursor powder;

[0012] (4) the precursor powder is placed in a crucible and transferred into a heat treatment furnace for heating, holding and calcination, and then cooled in the furnace to obtain a (M 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )O high-entropy oxide powder;

[0013] (5) the (M 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2High-entropy oxide powder is mixed with conductive agent and binder, and dispersant is added. The mixture is then ground to form a slurry. The slurry is then uniformly coated onto copper foil and dried under vacuum to obtain a novel rock salt phase high-entropy oxide anode material.

[0014] Furthermore, in step (1), the oxide of M is Na2CO3 or Li2O, with Na2CO3 having a purity ≥99.5wt% and Li2O having a purity ≥97wt%.

[0015] The oxides of Co, Ni, Cu, and Zn are Co3O4, NiO, CuO, and ZnO, respectively, with a purity of ≥99wt.%.

[0016] Furthermore, in step (2), the ball mill is a planetary ball mill, and the grinding jar is made of polytetrafluoroethylene;

[0017] The grinding balls are made of zirconium dioxide and come in two sizes: large and small.

[0018] The ball-to-material ratio is 10:1;

[0019] The liquid medium is ethanol;

[0020] Set the ball mill speed to 300rpm-500rpm and the ball milling time to 3h-6h.

[0021] Furthermore, the diameter of the large bead is 1cm, and the diameter of the small bead is 0.6cm, with a ratio of 1:1 between the large and small beads.

[0022] Furthermore, the temperature for heating and drying in step (3) is 60℃-100℃, and the drying time is 6h-12h.

[0023] Furthermore, the heating rate in step (4) is 2℃ / min-5℃ / min;

[0024] The calcination temperature is 900℃-1000℃, and the holding time is 12h-24h.

[0025] Furthermore, in step (5), the conductive agent is carbon black, the binder is polyvinylidene fluoride, and the dispersant is N-methylpyrrolidone.

[0026] Furthermore, (M) 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 The mass ratio of O powder, conductive agent, and binder is (6-8):(1-3):1;

[0027] The vacuum heating drying temperature is 80℃-120℃, and the time is 8h-12h.

[0028] Thirdly, the present invention provides an application of the above-mentioned novel rock salt phase high-entropy oxide anode material in lithium-ion batteries.

[0029] Advantages and effects of the present invention:

[0030] 1. This invention is the first to propose (Li 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )O and (Na 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 O-type rock salt phase high-entropy oxides, structurally stable, low-valence Li + Na + It can cause charge compensation in electrode materials, forming more oxygen vacancies, thereby improving electrochemical performance.

[0031] 2. The preparation process of the rock salt phase high entropy oxide anode material of the present invention is simple, and it can achieve the purpose of high-throughput synthesis. It has excellent specific capacity, good cycle life and cycle stability.

[0032] 3. The lithium-ion battery constructed according to the present invention has excellent electrochemical performance, exhibiting high reversible specific capacity and cycle stability, as well as maintaining excellent rate performance under large current density changes, thus ensuring high energy density and long cycle life of the battery. Attached Figure Description

[0033] Figure 1 The high-entropy oxide (Li) with a rock salt structure prepared in Example 1 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 X-ray diffraction pattern of O;

[0034] Figure 2 The graph shows the battery cycle performance test results of the coin-type lithium-ion secondary battery assembled in Example 1 at a current density of 0.1 A / g.

[0035] Figure 3 The graph shows the battery cycle performance test results of the coin-type lithium-ion secondary battery assembled in Example 1 at a current density of 0.5 A / g.

[0036] Figure 4 The graph shows the battery cycle performance test of the button lithium-ion secondary battery assembled in Example 1 at different current densities.

[0037] Figure 5The high-entropy oxide (Na) with a rock salt structure prepared in Example 2 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 X-ray diffraction pattern of O;

[0038] Figure 6 The graph shows the battery cycle performance test results of the coin-type lithium-ion secondary battery assembled in Example 2 at a current density of 0.1 A / g.

[0039] Figure 7 The graph shows the battery cycle performance test results of the coin-type lithium-ion secondary battery assembled in Example 2 at a current density of 0.5 A / g.

[0040] Figure 8 The graph shows the battery cycle performance test results of the button lithium-ion secondary battery assembled in Example 2 at different current densities. Detailed Implementation

[0041] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples.

[0042] A novel rock-salt phase high-entropy oxide anode material, wherein the molecular formula of the rock-salt phase high-entropy oxide anode material is (M 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )O, where M is Li or Na.

[0043] A method for preparing a novel rock-salt phase high-entropy oxide anode material includes the following steps:

[0044] (1) According to (M) 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 Five metals in O were in equimolar ratio. Five metal oxide powders were weighed out respectively. Among them, the oxide of M was Na2CO3 or Li2O, with Na2CO3 purity ≥99.5wt% and Li2O purity ≥97wt%. The oxides of Co, Ni, Cu and Zn were Co3O4, NiO, CuO and ZnO respectively, with a purity ≥99wt%.

[0045] (2) Place the five metal source oxide powders in a polytetrafluoroethylene ball milling jar, add two types of zirconium dioxide grinding beads (large (particle size: 1cm) and small (particle size: 0.6cm) and an appropriate amount of ethanol, control the ball-to-material ratio at 10:1, set the planetary ball mill speed to 300rpm-500rpm, and the ball milling time to 3h-6h for wet milling.

[0046] (3) After ball milling, the precursor slurry is dried at 60℃-100℃ for 6h-12h to obtain precursor powder.

[0047] (4) Place the precursor powder in a crucible, transfer it to a heat treatment furnace, heat it to 900-1000℃ at a heating rate of 2℃ / min-5℃ / min, hold it at that temperature for 12h-24h for calcination, and cool it with the furnace after calcination to obtain (M 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 O high-entropy oxide powder.

[0048] (5) M 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 High-entropy oxide powder was mixed with conductive agent carbon black and binder polyvinylidene fluoride in a mass ratio of (6-8):(1-3):1, dissolved in dispersant N-methylpyrrolidone, and ground to form a slurry. The slurry was then uniformly coated onto copper foil and vacuum dried at 80℃-120℃ for 8h-12h to obtain a novel rock salt phase high-entropy oxide anode material.

[0049] The application of the above-mentioned novel rock-salt phase high-entropy oxide anode material in lithium-ion batteries was investigated, and the electrochemical performance of the prepared electrode material was tested using a CR2032 coin cell.

[0050] Example 1

[0051] A novel rock-salt phase high-entropy oxide anode material, with the molecular formula (Li 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )O.

[0052] A novel high-entropy oxide of rock salt phase (Li 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 The preparation method of the O anode material includes the following steps:

[0053] (1) According to (Li 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2Five metals in equimolar ratio were used to weigh out 10 mmol of powders of Li2O (97 wt%), Co3O4 (99 wt.%), NiO (99 wt.%), CuO (99 wt.%) and ZnO (99 wt.%).

[0054] (2) Place the five metal oxide powders from step (1) into a 100 mL polytetrafluoroethylene ball milling jar, add two types of zirconium dioxide grinding beads (large (particle size: 1 cm) and small (particle size: 0.6 cm) and 30 mL of ethanol, control the ball-to-material ratio to 10:1, set the planetary ball mill speed to 300 rpm, and mill for 3 hours.

[0055] (3) After the precursor slurry is ball-milled, it is dried in an oven at 70°C for 12 hours to obtain precursor powder.

[0056] (4) The precursor powder was placed in an alumina crucible and transferred to a muffle furnace. The temperature was increased to 1000℃ at a rate of 5℃ / min and held for 12 hours for calcination. After calcination, the powder was cooled in the furnace to obtain (Li 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )O high-entropy oxide powder. Regarding this (Li 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 XRD tests were performed on high-entropy oxides, such as... Figure 1 As shown, a comparison with the standard card (JCPDS:47-1049) of NiO with a rock salt phase as a reference sample confirms the successful preparation of a high-entropy oxide (Li₂O₃) with a rock salt structure. 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )O.

[0057] (5) (Li) 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 High-entropy oxide powder was mixed with conductive agent carbon black and binder polyvinylidene fluoride in a mass ratio of 7:2:1, dissolved in dispersant N-methylpyrrolidone, and ground to form a slurry. The slurry was then uniformly coated onto copper foil and vacuum dried at 120°C for 8 hours to obtain a novel rock salt phase high-entropy oxide anode material.

[0058] The application of a novel rock-salt phase high-entropy oxide anode material in lithium-ion batteries was investigated. The electrochemical performance of the prepared electrode material was tested using a CR2032 coin cell.

[0059] Half-cell assembly was performed in an argon-atmosphere glove box (the glove box environment required a moisture partial pressure ≤0.1ppm and an oxygen partial pressure ≤0.1ppm). The novel rock-salt phase high-entropy oxide anode material prepared in Example 1 was cut into circular electrode sheets with a diameter of 1 cm using a slicer. A lithium metal sheet was used as the counter electrode, and a 1M lithium hexafluorophosphate solution (EC / EMC / DEC, volume ratio 1:1:1) was used as the electrolyte. Celgard 2400 lithium-ion secondary batteries were assembled. Subsequently, charge-discharge tests were conducted at room temperature using a constant current charge-discharge mode, with a voltage range of 0.01V-3.0V and current densities of 0.1A / g and 0.5A / g. The cycle performance of the battery was tested, and the rate performance was tested under varying current densities.

[0060] like Figure 2 As shown, when the current density is 0.1 A / g, (Li 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 The initial charge capacity of the O electrode was 719.7 mAh / g, and after 100 cycles, the charge capacity was 715.3 mAh / g, with a capacity retention rate of 99.39%. Figure 3 As shown, at a current density of 0.5 A / g, the charge specific capacity after 300 cycles is 549.7 mAh / g, with a capacity retention rate of 109%, indicating that (Li 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 The O anode material has excellent electrochemical cycling performance.

[0061] like Figure 4 As shown, the circuit was cyclically run for 10 cycles at a current density of 0.1 A / g, and then the current density was increased to 0.2 A / g, 0.5 A / g, 1 A / g, and 2 A / g, respectively, and cyclically run for 10 cycles each. (Li 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 The O electrode sequentially released specific capacities of 595.9 mAh / g, 528.3 mAh / g, 445.1 mAh / g, 375.2 mAh / g, and 299.8 mAh / g. After restoring the current density to 0.1 A / g and cycling for another 10 cycles, the reversible charging specific capacity recovered to 562 mAh / g, indicating that (Li...0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 O-type anode materials have high reversibility.

[0062] Example 2

[0063] A novel rock-salt phase high-entropy oxide anode material, with the molecular formula (Na) 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )O.

[0064] A novel high-entropy oxide of rock salt phase (Na) 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 The preparation method of the O anode material includes the following steps:

[0065] (1) According to (Na) 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 Five metals in equimolar ratio were used to weigh out 10 mmol of Na2CO3 (99.5 wt%), Co3O4 (99 wt.%), NiO (99 wt.%), CuO (99 wt.%) and ZnO (99 wt.%) powders respectively.

[0066] (2) Place the five metal oxide powders from step (1) into a 100 mL polytetrafluoroethylene ball milling jar, add two types of zirconium dioxide grinding beads (large (particle size: 1 cm) and small (particle size: 0.6 cm) and 30 mL of ethanol, control the ball-to-material ratio to 10:1, set the planetary ball mill speed to 300 rpm, and mill for 3 hours.

[0067] (3) After the ball milling, the precursor slurry was placed in an oven and dried at 70°C for 12 hours to obtain precursor powder.

[0068] (4) The precursor powder was placed in an alumina crucible and transferred to a muffle furnace. The temperature was increased to 1000°C at a rate of 5°C / min and held for 12 hours for calcination. After calcination, the powder was cooled in the furnace to obtain (Na) 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )O high-entropy oxide powder. Regarding this (Na 0.2 Co 0.2 Ni 0.2Cu 0.2 Zn 0.2 XRD tests were performed on high-entropy oxides, such as... Figure 5 As shown, a comparison with the standard card of NiO with a rock salt phase (JCPDS:47-1049) confirms the successful preparation of a high-entropy oxide (Na₂O) with a rock salt structure. 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )O.

[0069] (5) Will (Na 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 High-entropy oxide powder was mixed with conductive agent carbon black and binder polyvinylidene fluoride in a mass ratio of 7:2:1, dissolved in dispersant N-methylpyrrolidone, and ground to form a slurry. The slurry was then uniformly coated onto copper foil and vacuum dried at 120°C for 8 hours to obtain a novel rock salt phase high-entropy oxide anode material.

[0070] The application of a novel rock-salt phase high-entropy oxide anode material in lithium-ion batteries was investigated. The electrochemical performance of the prepared electrode material was tested using a CR2032 coin cell.

[0071] Half-cell assembly was performed in an argon-atmosphere glove box (the glove box environment required a moisture partial pressure ≤0.1ppm and an oxygen partial pressure ≤0.1ppm). The novel rock-salt phase high-entropy oxide anode material prepared in Example 1 was cut into circular electrode sheets with a diameter of 1 cm using a slicer. A lithium metal sheet was used as the counter electrode, and a 1M lithium hexafluorophosphate solution (EC / EMC / DEC, volume ratio 1:1:1) was used as the electrolyte. Celgard 2400 lithium-ion secondary batteries were assembled. Subsequently, charge-discharge tests were conducted at room temperature using a constant current charge-discharge mode, with a voltage range of 0.01V-3.0V and current densities of 0.1A / g and 0.5A / g. The cycle performance of the battery was tested, and the rate performance was tested under varying current densities.

[0072] like Figure 6 As shown, when the current density is 0.1 A / g, (Na 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 The initial charge capacity of the O electrode was 602.1 mAh / g, and after 100 cycles, the charge capacity was 547 mAh / g, with a capacity retention rate of 90.85%. Figure 7As shown, at a current density of 0.5 A / g, the charge specific capacity after 300 cycles is 415.5 mAh / g, with a capacity retention rate of 106%, indicating that (Na) 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 The O anode material has excellent electrochemical cycling performance.

[0073] like Figure 8 As shown, the circuit was cyclically run for 10 cycles at a current density of 0.1 A / g, and then the current density was increased to 0.2 A / g, 0.5 A / g, 1 A / g, and 2 A / g, respectively, and cyclically run for 10 cycles each. (Na) 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 The O electrode sequentially released specific capacities of 548.2 mAh / g, 484.8 mAh / g, 398.2 mAh / g, 327.3 mAh / g, and 254.6 mAh / g. After restoring the current density to 0.1 A / g and cycling for another 10 cycles, the reversible charging specific capacity recovered to 533 mAh / g, indicating that (Na...) 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 O-type anode materials have high reversibility.

[0074] Example 3

[0075] A novel rock-salt phase high-entropy oxide anode material, with the molecular formula (Li 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )O.

[0076] A novel high-entropy oxide of rock salt phase (Li 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 The preparation method of the O anode material includes the following steps:

[0077] (1) According to (Li 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2Five metals in equimolar ratio were used to weigh out 10 mmol of powders of Li2O (97 wt%), Co3O4 (99 wt.%), NiO (99 wt.%), CuO (99 wt.%) and ZnO (99 wt.%).

[0078] (2) Place the five metal oxide powders from step (1) into a 100 mL polytetrafluoroethylene ball milling jar, add two types of zirconium dioxide grinding beads (large (particle size: 1 cm) and small (particle size: 0.6 cm) and 30 mL of ethanol, control the ball-to-material ratio to 10:1, set the planetary ball mill speed to 300 rpm, and mill for 6 hours.

[0079] (3) After ball milling, the precursor slurry is placed in an oven and dried at 60°C for 10 hours to obtain precursor powder.

[0080] (4) The precursor powder was placed in an alumina crucible and transferred to a muffle furnace. The temperature was increased to 1000℃ at a rate of 2℃ / min and held for 24 hours for calcination. After calcination, the powder was cooled in the furnace to obtain (Li 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 O high-entropy oxide powder.

[0081] (5) (Li) 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 High-entropy oxide powder was mixed with conductive agent carbon black and binder polyvinylidene fluoride in a mass ratio of 6:3:1, dissolved in dispersant N-methylpyrrolidone, and ground to form a slurry. The slurry was then uniformly coated onto copper foil and vacuum dried at 80°C for 12 hours to obtain a novel rock salt phase high-entropy oxide anode material.

[0082] Example 4

[0083] A novel rock-salt phase high-entropy oxide anode material, with the molecular formula (Li 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )O.

[0084] A novel high-entropy oxide of rock salt phase (Li 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 The preparation method of the O anode material includes the following steps:

[0085] (1) According to (Li 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 Five metals in equimolar ratio were used to weigh out 10 mmol of powders of Li2O (97 wt%), Co3O4 (99 wt.%), NiO (99 wt.%), CuO (99 wt.%) and ZnO (99 wt.%).

[0086] (2) Place the five metal oxide powders from step (1) into a 100 mL polytetrafluoroethylene ball milling jar, add two types of zirconium dioxide grinding beads (large (particle size: 1 cm) and small (particle size: 0.6 cm) and 30 mL of ethanol, control the ball-to-material ratio to 10:1, set the planetary ball mill speed to 400 rpm, and mill for 5 hours.

[0087] (3) After ball milling, the precursor slurry is placed in an oven and dried at 80°C for 8 hours to obtain precursor powder.

[0088] (4) The precursor powder was placed in an alumina crucible and transferred to a muffle furnace. The temperature was increased to 1000℃ at a rate of 3℃ / min and held for 16h for calcination. After calcination, the powder was cooled in the furnace to obtain (Li 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 O high-entropy oxide powder.

[0089] (5) (Li) 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 High-entropy oxide powder was mixed with conductive agent carbon black and binder polyvinylidene fluoride in a mass ratio of 8:1:1, dissolved in dispersant N-methylpyrrolidone, and ground to form a slurry. The slurry was then uniformly coated onto copper foil and vacuum dried at 100°C for 10 hours to obtain a novel rock salt phase high-entropy oxide anode material.

[0090] Example 5

[0091] A novel rock-salt phase high-entropy oxide anode material, with the molecular formula (Li 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )O.

[0092] A novel high-entropy oxide of rock salt phase (Li 0.2 Co 0.2 Ni 0.2Cu 0.2 Zn 0.2 The preparation method of the O anode material includes the following steps:

[0093] (1) According to (Li 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 Five metals in equimolar ratio were used to weigh out 10 mmol of powders of Li2O (97 wt%), Co3O4 (99 wt.%), NiO (99 wt.%), CuO (99 wt.%) and ZnO (99 wt.%).

[0094] (2) Place the five metal oxide powders from step (1) into a 100 mL polytetrafluoroethylene ball milling jar, add two types of zirconium dioxide grinding beads (large (particle size: 1 cm) and small (particle size: 0.6 cm) and 30 mL of ethanol, control the ball-to-material ratio to 10:1, set the planetary ball mill speed to 500 rpm, and mill for 4 hours.

[0095] (3) After ball milling, the precursor slurry was placed in an oven and dried at 100°C for 6 hours to obtain precursor powder.

[0096] (4) The precursor powder was placed in an alumina crucible and transferred to a muffle furnace. The temperature was increased to 1000℃ at a rate of 5℃ / min and held for 20h for calcination. After calcination, the powder was cooled in the furnace to obtain (Li 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 O high-entropy oxide powder.

[0097] (5) (Li) 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 High-entropy oxide powder was mixed with conductive agent carbon black and binder polyvinylidene fluoride in a mass ratio of 6:3:1, dissolved in dispersant N-methylpyrrolidone, and ground to form a slurry. The slurry was then uniformly coated onto copper foil and vacuum dried at 120°C for 8 hours to obtain a novel rock salt phase high-entropy oxide anode material.

[0098] Example 6

[0099] A novel rock-salt phase high-entropy oxide anode material, with the molecular formula (Na) 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )O.

[0100] A novel high-entropy oxide of rock salt phase (Na) 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 The preparation method of the O anode material includes the following steps:

[0101] (1) According to (Na) 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 Five metals in equimolar ratio were used to weigh out 10 mmol of Na2CO3 (99.5 wt%), Co3O4 (99 wt.%), NiO (99 wt.%), CuO (99 wt.%) and ZnO (99 wt.%) powders respectively.

[0102] (2) Place the five metal oxide powders from step (1) into a 100 mL polytetrafluoroethylene ball milling jar, add two types of zirconium dioxide grinding beads (large (particle size: 1 cm) and small (particle size: 0.6 cm) and 30 mL of ethanol, control the ball-to-material ratio to 10:1, set the planetary ball mill speed to 400 rpm, and mill for 6 hours.

[0103] (3) After the precursor slurry is ball-milled, it is dried in an oven at 60°C for 12 hours to obtain precursor powder.

[0104] (4) The precursor powder was placed in an alumina crucible and transferred to a muffle furnace. The temperature was increased to 1000℃ at a rate of 2℃ / min and held for 18h for calcination. After calcination, the powder was cooled in the furnace to obtain (Na) 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 O high-entropy oxide powder.

[0105] (5) Will (Na 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 High-entropy oxide powder was mixed with conductive agent carbon black and binder polyvinylidene fluoride in a mass ratio of 6:3:1, dissolved in dispersant N-methylpyrrolidone, and ground to form a slurry. The slurry was then uniformly coated onto copper foil and vacuum dried at 80°C for 12 hours to obtain a novel rock salt phase high-entropy oxide anode material.

[0106] Example 7

[0107] A novel rock-salt phase high-entropy oxide anode material, with the molecular formula (Na) 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )O.

[0108] A novel high-entropy oxide of rock salt phase (Na) 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 The preparation method of the O anode material includes the following steps:

[0109] (1) According to (Na) 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 Five metals in equimolar ratio were used to weigh out 10 mmol of Na2CO3 (99.5 wt%), Co3O4 (99 wt.%), NiO (99 wt.%), CuO (99 wt.%) and ZnO (99 wt.%) powders respectively.

[0110] (2) Place the five metal oxide powders from step (1) into a 100 mL polytetrafluoroethylene ball milling jar, add two types of zirconium dioxide grinding beads (large (particle size: 1 cm) and small (particle size: 0.6 cm) and 30 mL of ethanol, control the ball-to-material ratio to 10:1, set the planetary ball mill speed to 300 rpm, and mill for 4 hours.

[0111] (3) After ball milling, the precursor slurry is placed in an oven and dried at 80°C for 10 hours to obtain precursor powder.

[0112] (4) The precursor powder was placed in an alumina crucible and transferred to a muffle furnace. The temperature was increased to 900°C at a rate of 5°C / min and held for 12 hours for calcination. After calcination, the powder was cooled in the furnace to obtain (Na) 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 O high-entropy oxide powder.

[0113] (5) Will (Na 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2High-entropy oxide powder was mixed with conductive agent carbon black and binder polyvinylidene fluoride in a mass ratio of 8:1:1, dissolved in dispersant N-methylpyrrolidone, and ground to form a slurry. The slurry was then uniformly coated onto copper foil and vacuum dried at 100°C for 10 hours to obtain a novel rock salt phase high-entropy oxide anode material.

[0114] Example 8

[0115] A novel rock-salt phase high-entropy oxide anode material, with the molecular formula (Na) 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )O.

[0116] A novel high-entropy oxide of rock salt phase (Na) 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 The preparation method of the O anode material includes the following steps:

[0117] (1) According to (Na) 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 Five metals in equimolar ratio were used to weigh out 10 mmol of Na2CO3 (99.5 wt%), Co3O4 (99 wt.%), NiO (99 wt.%), CuO (99 wt.%) and ZnO (99 wt.%) powders respectively.

[0118] (2) Place the five metal oxide powders from step (1) into a 100 mL polytetrafluoroethylene ball milling jar, add two types of zirconium dioxide grinding beads (large (particle size: 1 cm) and small (particle size: 0.6 cm) and 30 mL of ethanol, control the ball-to-material ratio to 10:1, set the planetary ball mill speed to 500 rpm, and mill for 3 hours.

[0119] (3) After the precursor slurry is ball-milled, it is dried in an oven at 100°C for 6 hours to obtain precursor powder.

[0120] (4) The precursor powder was placed in an alumina crucible and transferred to a muffle furnace. The temperature was increased to 1000℃ at a rate of 3℃ / min and held for 24 hours for calcination. After calcination, the powder was cooled in the furnace to obtain (Na). 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 O high-entropy oxide powder.

[0121] (5) Will (Na 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 High-entropy oxide powder was mixed with conductive agent carbon black and binder polyvinylidene fluoride in a mass ratio of 7:2:1, dissolved in dispersant N-methylpyrrolidone, and ground to form a slurry. The slurry was then uniformly coated onto copper foil and vacuum dried at 120°C for 8 hours to obtain a novel rock salt phase high-entropy oxide anode material.

Claims

1. A novel rock-salt phase high-entropy oxide anode material, characterized in that, The molecular formula of the rock salt phase high-entropy oxide anode material is (M 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 )O, where M is Li or Na.

2. A method for preparing the novel rock-salt phase high-entropy oxide anode material according to claim 1, characterized in that, Includes the following steps: (1) According to (M) 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 Five metals in equimolar ratio were used to weigh out powders of the five metal oxides. (2) Place the five metal oxide powders in a ball mill jar, add the ball milling beads and liquid medium, set the ball milling parameters, and perform wet milling; (3) The precursor slurry after ball milling is heated and dried to obtain precursor powder; (4) Place the precursor powder in a crucible, transfer it to a heat treatment furnace for heating and holding at a certain temperature for calcination, and cool it with the furnace after calcination to obtain (M 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 O high-entropy oxide powder; (5) M 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 High-entropy oxide powder is mixed with conductive agent and binder, and dispersant is added. The mixture is then ground to form a slurry. The slurry is then uniformly coated onto copper foil and dried under vacuum to obtain a novel rock salt phase high-entropy oxide anode material.

3. The preparation method of the novel rock salt phase high-entropy oxide anode material as described in claim 2, characterized in that, In step (1), the oxide of M is either Na2CO3 or Li2O, with Na2CO3 having a purity ≥ 99.5 wt% and Li2O having a purity ≥ 97 wt%. The oxides of Co, Ni, Cu, and Zn are Co3O4, NiO, CuO, and ZnO, respectively, with a purity of ≥99wt.%.

4. The preparation method of the novel rock-salt phase high-entropy oxide anode material as described in claim 2, characterized in that, In step (2), the ball mill is a planetary ball mill, and the grinding jar is made of polytetrafluoroethylene; The grinding balls are made of zirconium dioxide and come in two sizes: large and small. The ball-to-material ratio is 10:1; The liquid medium is ethanol; Set the ball mill speed to 300rpm-500rpm and the ball milling time to 3h-6h.

5. The preparation method of the novel rock salt phase high-entropy oxide anode material as described in claim 4, characterized in that, The large bead has a diameter of 1cm, and the small bead has a diameter of 0.6cm, with a ratio of 1:

1.

6. The preparation method of the novel rock-salt phase high-entropy oxide anode material as described in claim 2, characterized in that, The temperature for heating and drying in step (3) is 60℃-100℃, and the drying time is 6h-12h.

7. The preparation method of the novel rock salt phase high-entropy oxide anode material as described in claim 2, characterized in that, Step (4) The heating rate is 2℃ / min-5℃ / min; The calcination temperature is 900℃-1000℃, and the holding time is 12h-24h.

8. The preparation method of the novel rock salt phase high-entropy oxide anode material as described in claim 2, characterized in that, In step (5), the conductive agent is carbon black, the binder is polyvinylidene fluoride, and the dispersant is N-methylpyrrolidone.

9. The preparation method of the novel rock salt phase high-entropy oxide anode material as described in claim 8, characterized in that, (M 0.2 Co 0.2 Ni 0.2 Cu 0.2 Zn 0.2 The mass ratio of O powder, conductive agent, and binder is (6-8):(1-3):1; The vacuum heating drying temperature is 80℃-120℃, and the time is 8h-12h.

10. The application of the novel rock-salt phase high-entropy oxide anode material as described in claim 1 in lithium-ion batteries.

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