Method for preparing silicon monoxide negative electrode material with low energy consumption and high efficiency

Abstract

The application belongs to the field of electrochemistry and relates to preparation of silicon monoxide negative electrode material, in particular to a method for efficiently preparing silicon monoxide negative electrode material with low energy consumption. The preparation method comprises the following steps: mixing and stirring silicon monoxide raw material and lithium source under dry conditions, high-temperature sintering, water washing, drying, ball milling, and then water washing again until the pH is 6-8, and drying to obtain silicon monoxide negative electrode material. The preparation method provided by the application solves the problems of low initial coulombic efficiency and poor cycle performance of silicon monoxide negative electrode material in the prior art. The silicon monoxide negative electrode material is efficiently prepared with low energy consumption according to the technical scheme of the application, the material is not sensitive to water and oxygen, and after being applied to a lithium ion half battery, the material has the advantages of high initial coulombic efficiency and stable cycle performance, the initial coulombic efficiency is > 80% under a current density of 100 mA / g, and the capacity retention rate is 94.6% after 200 cycles under a current density of 500 mA / g.

Description

Technical Field

[0001] This invention belongs to the field of electrochemistry and relates to the preparation of silicon suboxide anode materials, specifically to a method for preparing silicon suboxide anode materials with low energy consumption and high efficiency. Background Technology

[0002] New energy vehicles are facing increasingly severe range anxiety. High-energy-density power battery technology will continue to develop rapidly in the future, providing significant opportunities for the development of power batteries, while also posing higher requirements.

[0003] As a crucial component of lithium-ion batteries, the specific capacity of anode materials has a decisive impact on the energy density of lithium-ion batteries. Currently recognized as the most commercially promising next-generation anode material, silicon suboxide (SiO2) boasts a theoretical specific capacity as high as 2400 mAh / g. Furthermore, the widespread distribution of SiO2 elements in the Earth's crust, its low production cost, and its good compatibility with existing lithium-ion battery anode production systems make SiO2 the most likely new anode material to replace existing graphite materials. However, SiO2 materials still face challenges, such as low initial coulombic efficiency, poor conductivity, complex interfacial reactions, and significant volume effects during lithiation / delithiation processes, which are key obstacles to its large-scale commercialization.

[0004] Chinese patent CN112164779A discloses a carbon-coated silicon-based anode material and its preparation method. The method involves uniformly mixing a lithium source and a silicon source, performing a pre-lithiation reaction under an inert atmosphere, then adding an organic carbon source, and continuing to calcine at high temperature. No cooling occurs during the pre-lithiation reaction and high-temperature calcination process, resulting in the carbon-coated silicon-based anode material. However, the silicon-based anode material prepared by this method exhibits low initial coulombic efficiency and poor cycle stability; furthermore, the preparation process is complex, time-consuming, and energy-intensive. Summary of the Invention

[0005] To address the technical problems of low initial coulombic efficiency and poor cycle performance of silicon suboxide anode materials in existing technologies, this invention proposes a low-energy-consumption and high-efficiency method for preparing silicon suboxide anode materials. The silicon suboxide anode material prepared by this invention is insensitive to water and oxygen, making it suitable for industrial application. Furthermore, when applied to lithium-ion half-cells, it exhibits advantages such as extremely high initial coulombic efficiency and stable cycle performance. Simultaneously, it achieves efficient preparation of silicon suboxide anode materials under low-energy-consumption reaction conditions in a short time.

[0006] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0007] A method for preparing silicon suboxide anode materials with low energy consumption and high efficiency includes the following steps:

[0008] (1) D50 silicon suboxide raw material with a thickness of 3 to 25 μm and lithium source were mixed in a degassing machine at a ratio of 20:1 to 50:1 to obtain precursor I;

[0009] (2) Place precursor II into a tube furnace, use a vacuum pump to evacuate the pressure of the tube furnace to -0.1MPa and then introduce argon gas. Repeat this process 3 times, and then carry out a high-temperature reaction at 800-850℃ with a heating rate of 2-10℃ / min and a holding time of 0-20min to obtain precursor II.

[0010] (3) Precursor II was washed with deionized water until pH=6-8 and dried to obtain precursor III;

[0011] (4) Precursor III was ball-milled at 200-300 r / min for 0.5 h in a ball mill jar to obtain precursor IV;

[0012] (5) The precursor IV was washed with deionized water until pH=6-8 and dried to obtain the Si-SiO-Li2Si2O5 composite material.

[0013] Furthermore, in step (1), the silicon suboxide raw material is prepared by controlling the particle size and morphology using a ball mill, crusher or pulverizer, and then by sieving and demagnetizing.

[0014] Furthermore, in step (1), the silica raw material is crushed by a jaw roller combination and then pulverized by airflow, and after screening and demagnetization, the D50 is between 3 and 25 μm.

[0015] Furthermore, in step (1), the silica raw material particles are spherical in shape.

[0016] Furthermore, the dried silicon suboxide raw material and lithium source in step (1) are in powder form, with a D50 between 3 and 25 μm.

[0017] Furthermore, in step (1), the degassing machine has a revolution speed of 800 rpm, a rotation speed of 160 rpm, and a mixing time of 100 s.

[0018] Furthermore, in step (2), the inert atmosphere is any one or a combination of at least two of nitrogen, argon, helium or neon.

[0019] Furthermore, the temperature was raised to 800–850°C after holding at that temperature for 0 minutes, and then the high-temperature reaction was stopped to obtain precursor II. During this process of raising the temperature to 800–850°C, the reaction had already formed the Si-SiO-Li2Si2O5 composite material.

[0020] Furthermore, when there is too much lithium source, a prolonged high-temperature reaction may generate more other irreversible lithium silicates, resulting in the failure to obtain reversible lithium silicate Li2Si2O5, while simultaneously catalyzing the generation of a large amount of SiO2. Even when the ratio of silicon suboxide to lithium source is between 20:1 and 50:1, a prolonged high-temperature reaction time will still generate other irreversible lithium silicates. When the high-temperature reaction time is controlled between 0 and 20 minutes, the ratio of silicon suboxide to lithium source is unsuitable, and reversible silicate Li2Si2O5 will also fail to be obtained. Therefore, only by simultaneously controlling the ratio of silicon suboxide to lithium source and the high-temperature reaction time can Si-SiO-Li2Si2O5 composite materials be prepared under suitable conditions.

[0021] Furthermore, by repeatedly washing with water and controlling the pH to 6-8, acidic or alkaline substances generated during the reaction can be washed away, as well as irreversible silicates that do not participate in the electrochemical reaction, thus avoiding the impact of acidic or alkaline substances and irreversible silicates on battery performance.

[0022] Furthermore, the application of the low-energy-consumption and high-efficiency silicon suboxide anode material in lithium-ion battery anode materials.

[0023] The present invention has the following beneficial effects:

[0024] 1. This invention prepares a Si-SiO-Li2Si2O5 composite material with a low lithium content, a short high-temperature calcination time, and repeated water washing steps. Firstly, the invention generates lithium oxide from silicon suboxide raw material and a selected lithium source through a high-temperature process, further catalyzing the formation of Si microcrystals at a low energy barrier, thus lowering the reaction temperature and shortening the reaction time. Secondly, the low lithium content and short reaction time ensure the formation of reversible silicate Li2Si2O5 and irreversible silicate during the reaction, while avoiding the generation of large amounts of SiO2. Simultaneously, repeated water washing to control the pH at 6-8 removes acidic or alkaline substances generated during the reaction and washes away irreversible silicates that do not participate in the electrochemical reaction, avoiding the impact of acidic or alkaline substances and irreversible silicates on battery performance, ultimately forming the Si-SiO-Li2Si2O5 composite material.

[0025] 2. In the Si-SiO-Li2Si2O5 composite material prepared in this invention, on the one hand, the Si microcrystalline stone obtained from the reaction is encapsulated in SiO and Li2Si2O5, which can effectively suppress the volume expansion of Si during charging and discharging; on the other hand, unlike other irreversible silicates that do not participate in electrochemical reactions, the reversible silicate Li2Si2O5 obtained in this invention can be reused during battery charging and discharging, and can desorb Li during charging. + Increased capacity, during discharge, can be achieved by Li +The SiO-Li₂Si₂O₅ reacts with silicon suboxide to form a reversible lithium silicate, Li₂Si₂O₅. Therefore, in the prepared Si-SiO-Li₂Si₂O₅ composite material, the microcrystalline Si and the reversible silicate Li₂Si₂O₅, exhibiting higher initial coulombic efficiency, can effectively improve the initial coulombic efficiency of the composite material. Furthermore, repeated water washing of the Si-SiO-Li₂Si₂O₅ composite material indicates that it is insensitive to water and oxygen, possesses good safety, and is suitable for industrial application.

[0026] 3. The low-energy-consumption, high-efficiency silicon suboxide anode material prepared by the method provided in this invention exhibits excellent initial coulombic efficiency and superior cycle stability when used as an anode material in lithium-ion half-cells. At a current density of 100 mA / g, the initial coulombic efficiency is >80%; at a current density of 500 mA / g, the capacity retention rate after 200 cycles is 94.6%. Therefore, the low-energy-consumption, high-efficiency silicon suboxide anode material prepared by this invention is suitable for power batteries and has broad market application prospects. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 The image is a scanning electron microscope image of the Si-SiO-Li2Si2O5 composite material prepared in Example 7 of this invention at a magnification of 10.0k.

[0029] Figure 2 The Si-SiO-Li2Si2O5 composite material prepared in Example 7 of this invention has a 5nm... -1 Proportional transmission electron microscope diffraction images.

[0030] Figure 3 This is a transmission electron microscope image of the Si-SiO-Li2Si2O5 composite material prepared in Example 7 of the present invention at a magnification of 105k.

[0031] Figure 4 The image shows the XRD pattern of the Si-SiO-Li2Si2O5 composite material prepared in Example 7 of this invention.

[0032] Figure 5 The first charge-discharge curve of the Si-SiO-Li2Si2O5 composite material prepared in Example 7 of this invention.

[0033] Figure 6The graph shows the cycling data of the Si-SiO-Li2Si2O5 composite material prepared in Example 7 of this invention at 100 mA / g (2 weeks) and 500 mA / g (198 weeks) for 200 weeks. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] In the following examples, the microstructure of the prepared samples was determined using a Hitachi Regulus 8100 scanning electron microscope. Battery performance was tested using a LANHE CT2001A battery testing system manufactured by Wuhan Landian Electronics Co., Ltd.

[0036] In step (2), after precursor II is cooled to room temperature in the tubular furnace, step (3) is performed to wash with water until pH = 6-8.

[0037] The silicon suboxide anode material prepared according to this invention, a conductive agent, and a binder were mixed into a slurry at a mass ratio of 93%:3%:4%, uniformly coated onto copper foil, and dried to obtain an electrode sheet. The conductive agent was Super P, and the binder consisted of 1.5% CMC and 2.5% SBR. A 1.0 mol / L LiPF6 electrolyte was used, with a solvent composition EC:DEC:DMC volume ratio of 1:1:1, and 10% FEC was added. A microporous polypropylene membrane was selected, and a lithium sheet was used as the counter electrode to assemble a CR2025 coin cell. The first cycle test used a current density of 100 mA / g and a voltage range of 0.005–2.0 V. Constant current cycling performance tests were conducted at 25°C with a current density of 500 mA / g and a voltage range of 0.005–2 V.

[0038] Example 1

[0039] This embodiment describes a method for preparing silicon suboxide anode materials with low energy consumption and high efficiency. The steps are as follows:

[0040] (1) D50 was mixed with 3μm silica raw material and lithium nitrate in a degassing machine at a ratio of 20:1 to obtain precursor I;

[0041] (2) Place precursor II into a tube furnace, use a vacuum pump to evacuate the pressure of the tube furnace to -0.1MPa and then introduce helium gas. Repeat this process 3 times, and then carry out a high-temperature reaction at 800℃ with a heating rate of 2℃ / min and hold for 5min to obtain precursor II.

[0042] (3) Precursor II was washed with deionized water until pH=6-8 and dried to obtain precursor III;

[0043] (4) Precursor III was ball-milled at 200 r / min for 0.5 h in a ball mill jar to obtain precursor IV;

[0044] (5) The precursor IV was washed with deionized water to pH 6-8 and dried to obtain the Si-SiO-Li2Si2O5 composite material;

[0045] The obtained Si-SiO-Li2Si2O5 composite material was prepared into a slurry, coated and assembled into a lithium-ion half-cell. When tested at a current density of 100 mA / g, the first charge specific capacity reached 1398 mAh / g and the first coulombic efficiency was 80.2%, which showed good first coulombic efficiency.

[0046] Example 2

[0047] This embodiment describes a method for preparing silicon suboxide anode materials with low energy consumption and high efficiency. The steps are as follows:

[0048] (1) D50 was mixed with 5μm silica raw material and lithium acetate in a degassing machine at a ratio of 30:1 to obtain precursor I;

[0049] (2) Place precursor II into a tube furnace, use a vacuum pump to evacuate the pressure of the tube furnace to -0.1MPa and then introduce argon gas. Repeat this process 3 times, and then carry out a high-temperature reaction at 810℃ with a heating rate of 3℃ / min and hold for 20min to obtain precursor II.

[0050] (3) Precursor II was washed with deionized water until pH=6-8 and dried to obtain precursor III;

[0051] (4) Precursor III was ball-milled at 300 r / min for 0.5 h in a ball mill jar to obtain precursor IV;

[0052] (5) The precursor IV was washed with deionized water until pH=6-8 and dried to obtain the Si-SiO-Li2Si2O5 composite material.

[0053] The obtained Si-SiO-Li2Si2O5 composite material was prepared into a slurry, coated and assembled into a lithium-ion half-cell. When tested at a current density of 100 mA / g, the first charge specific capacity reached 1290 mAh / g and the first coulombic efficiency was 81.5%, which showed good first coulombic efficiency.

[0054] Example 3

[0055] This embodiment describes a method for preparing silicon suboxide anode materials with low energy consumption and high efficiency. The steps are as follows:

[0056] (1) D50 was mixed with 25μm silica raw material and lithium hydroxide in a degassing machine at a ratio of 40:1 to obtain precursor I;

[0057] (2) Place precursor II into a tube furnace, use a vacuum pump to evacuate the pressure of the tube furnace to -0.1MPa and then introduce nitrogen gas. Repeat this process 3 times, and then carry out a high-temperature reaction at 820℃ with a heating rate of 5℃ / min and hold for 15min to obtain precursor II.

[0058] (3) Precursor II was washed with deionized water until pH=6-8 and dried to obtain precursor III;

[0059] (4) Precursor III was ball-milled at 250 r / min for 0.5 h in a ball mill jar to obtain precursor IV;

[0060] (5) The precursor IV was washed with deionized water until pH=6-8 and dried to obtain the Si-SiO-Li2Si2O5 composite material.

[0061] The obtained Si-SiO-Li2Si2O5 composite material was prepared into a slurry, coated and assembled into a lithium-ion half-cell. When tested at a current density of 100 mA / g, the first charge specific capacity reached 1403 mAh / g and the first coulombic efficiency was 80.6%, which showed good first coulombic efficiency.

[0062] Example 4

[0063] This embodiment describes a method for preparing silicon suboxide anode materials with low energy consumption and high efficiency. The steps are as follows:

[0064] (1) D50 was mixed with 10μm silica raw material and lithium nitrate in a degassing machine at a ratio of 50:1 to obtain precursor I;

[0065] (2) Place precursor II into a tube furnace, use a vacuum pump to evacuate the pressure of the tube furnace to -0.1MPa and then introduce nitrogen gas. Repeat this process 3 times, and then carry out a high-temperature reaction at 840℃ with a heating rate of 10℃ / min and hold for 20min to obtain precursor II.

[0066] (3) Precursor II was washed with deionized water until pH=6-8 and dried to obtain precursor III;

[0067] (4) Precursor III was ball-milled at 260 r / min for 0.5 h in a ball mill jar to obtain precursor IV;

[0068] (5) The precursor IV was washed with deionized water until pH=6-8 and dried to obtain the Si-SiO-Li2Si2O5 composite material.

[0069] The obtained Si-SiO-Li2Si2O5 composite material was prepared into a slurry, coated and assembled into a lithium-ion half-cell. When tested at a current density of 100 mA / g, the first charge specific capacity reached 1364 mAh / g and the first coulombic efficiency was 80.4%, which showed good first coulombic efficiency.

[0070] Example 5

[0071] This embodiment describes a method for preparing silicon suboxide anode materials with low energy consumption and high efficiency. The steps are as follows:

[0072] (1) D50 was mixed with 15μm silica raw material and lithium hydroxide in a degassing machine at a ratio of 50:1 to obtain precursor I;

[0073] (2) Place precursor II into a tube furnace, use a vacuum pump to evacuate the tube furnace pressure to -0.1MPa and then introduce argon gas. Repeat this process 3 times, and then carry out a high-temperature reaction at 835℃ with a heating rate of 3℃ / min and hold for 12min to obtain precursor II.

[0074] (3) Precursor II was washed with deionized water until pH=6-8 and dried to obtain precursor III;

[0075] (4) Precursor III was ball-milled at 200 r / min for 0.5 h in a ball mill jar to obtain precursor IV;

[0076] (5) The precursor IV was washed with deionized water until pH=6-8 and dried to obtain the Si-SiO-Li2Si2O5 composite material.

[0077] The obtained Si-SiO-Li2Si2O5 composite material was prepared into a slurry, coated and assembled into a lithium-ion half-cell. When tested at a current density of 100mA / g, the first charge specific capacity reached 1420mAh / g and the first coulombic efficiency was 80.9%, which showed good first coulombic efficiency.

[0078] Example 6

[0079] This embodiment describes a method for preparing silicon suboxide anode materials with low energy consumption and high efficiency. The steps are as follows:

[0080] (1) D50 was mixed with 3μm silica raw material and lithium nitrate in a degassing machine at a ratio of 30:1 to obtain precursor I;

[0081] (2) Place precursor II into a tube furnace, use a vacuum pump to evacuate the pressure of the tube furnace to -0.1MPa and then introduce argon gas. Repeat this process 3 times, and then carry out a high-temperature reaction at 815℃ with a heating rate of 8℃ / min and a holding time of 0min to obtain precursor II.

[0082] (3) Precursor II was washed with deionized water until pH=6-8 and dried to obtain precursor III;

[0083] (4) Precursor III was ball-milled at 300 r / min for 0.5 h in a ball mill jar to obtain precursor IV;

[0084] (5) The precursor IV was washed with deionized water until pH=6-8 and dried to obtain the Si-SiO-Li2Si2O5 composite material.

[0085] The obtained Si-SiO-Li2Si2O5 composite material was prepared into a slurry, coated and assembled into a lithium-ion half-cell. The first charge specific capacity reached 1325 mAh / g and the first coulombic efficiency was 82.1%, which is good.

[0086] Example 7

[0087] This embodiment describes a method for preparing silicon suboxide anode materials with low energy consumption and high efficiency, and its application. The steps are as follows:

[0088] (1) D50 was mixed with 3μm silica raw material and lithium hydroxide in a degassing machine at a ratio of 40:1 to obtain precursor I;

[0089] (2) Place precursor II into a tube furnace, use a vacuum pump to evacuate the pressure of the tube furnace to -0.1MPa and then introduce nitrogen gas. Repeat this process 3 times, and then carry out a high-temperature reaction at 800℃ with a heating rate of 5℃ / min and hold for 10min to obtain precursor II.

[0090] (3) Precursor II was washed with deionized water until pH=6-8 and dried to obtain precursor III;

[0091] (4) Precursor III was ball-milled at 250 r / min for 0.5 h in a ball mill jar to obtain precursor IV;

[0092] (5) The precursor IV was washed with deionized water until pH=6-8 and dried to obtain the Si-SiO-Li2Si2O5 composite material.

[0093] Figure 1 The image is a scanning electron microscope (SEM) image of the Si-SiO-Li2Si2O5 composite material prepared in this embodiment at a magnification of 10.0 k.

[0094] Figure 2 The Si-SiO-Li2Si2O5 composite material prepared in this embodiment has a wavelength of 5 nm. -1 The transmission electron microscope diffraction image is of a certain scale. The diffraction rings corresponding to Si microcrystals and reversible silicate Li2Si2O5 can be clearly seen in the diffraction image.

[0095] Figure 3 The image shows a transmission electron microscope (TEM) image of the Si-SiO-Li2Si2O5 composite material prepared in this embodiment at 105k magnification. The TEM image clearly shows the lattice fringes of Si microcrystals and the reversible silicate Li2Si2O5.

[0096] Figure 4 The XRD image of the Si-SiO-Li2Si2O5 composite material prepared in this embodiment shows the presence of three distinct Si peaks, and a certain amount of lithium silicate is also visible in the image.

[0097] (6) The obtained Si-SiO-Li2Si2O5 composite material was prepared into a slurry, coated and assembled into a lithium-ion half-cell.

[0098] Figure 5 The first charge-discharge curve of the Si-SiO-Li2Si2O5 composite material prepared in Example 7 of this invention is shown below. Figure 5 As shown, when tested at a current density of 100mA / g, the initial charge specific capacity reached 1419mAh / g, and the initial coulombic efficiency was 82.5%.

[0099] Figure 6 The following are the cycling data graphs for the Si-SiO-Li2Si2O5 composite material prepared in this embodiment at 100 mA / g (2 weeks) and 500 mA / g (198 weeks), as shown in the figure. Figure 6 As shown, the capacity retention rate is 94.6% after 200 cycles at a current density of 500 mA / g.

[0100] Comparative Example 1

[0101] This comparative example illustrates the preparation method of the silicon suboxide anode material obtained in Example 7 through steps (1) and (2), as follows:

[0102] (1) D50 was mixed with 3μm silica raw material and lithium hydroxide in a degassing machine at a ratio of 40:1 to obtain precursor I;

[0103] (2) Precursor II was placed in a tube furnace. The pressure of the tube furnace was evacuated to -0.1 MPa using a vacuum pump and nitrogen was introduced. This process was repeated 3 times. Then, a high-temperature reaction was carried out at 800℃ with a heating rate of 5℃ / min and a holding time of 10min to obtain the composite material.

[0104] The obtained composite material was prepared into a slurry, coated, and assembled into a lithium-ion half-cell. Tested at a current density of 100 mA / g, the initial charge specific capacity reached 1034 mAh / g, and the initial coulombic efficiency was 74.5%. After 200 cycles at a current density of 500 mA / g, the capacity retention was 52.3%. Compared to Example 7, this comparative example lacked a water washing step, resulting in the presence of unremoved lithium source and irreversible lithium silicate in the material, thus affecting the electrochemical performance of the composite material.

[0105] Comparative Example 2

[0106] This comparative example illustrates the preparation method of the silicon suboxide anode material obtained by extending the heat preservation time in step (2) of Example 7. The steps are as follows:

[0107] (1) D50 was mixed with 3μm silica raw material and lithium hydroxide in a degassing machine at a ratio of 40:1 to obtain precursor I;

[0108] (2) Place precursor II into a tube furnace, use a vacuum pump to evacuate the pressure of the tube furnace to -0.1MPa and then introduce nitrogen gas. Repeat this process 3 times, and then carry out a high-temperature reaction at 800℃ with a heating rate of 5℃ / min and hold for 3h to obtain precursor II.

[0109] (3) Precursor II was washed with deionized water until pH=6-8 and dried to obtain precursor III;

[0110] (4) Precursor III was ball-milled at 250 r / min for 0.5 h in a ball mill jar to obtain precursor IV;

[0111] (5) The precursor IV was washed with deionized water until pH=6-8 and then dried to obtain the composite material.

[0112] The obtained composite material was prepared into a slurry, coated, and assembled into a lithium-ion half-cell. Tested at a current density of 100 mA / g, the initial charge specific capacity reached 1253 mAh / g, with an initial coulombic efficiency of 76.5%. After 200 cycles at a current density of 500 mA / g, the capacity retention was 75.6%. Compared to Example 7, this comparative example extended the high-temperature holding time, increased the reaction time, and generated a large amount of SiO2 and other irreversible lithium silicates, resulting in poorer electrochemical performance.

[0113] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing silicon suboxide anode materials with low energy consumption and high efficiency, characterized in that, The steps are as follows: (1) Mixing raw materials with lithium source: After mixing and stirring silicon suboxide and lithium source under dry conditions, precursor I is obtained; the mass ratio of lithium source to silicon suboxide is 1:(20~50). (2) High-temperature sintering: The precursor I obtained in step (1) is sintered at high temperature in an inert atmosphere to obtain precursor II; the high-temperature sintering temperature is 800~850℃, the heating rate is 2~10℃ / min, and the high-temperature sintering time is 0~20min. (3) Water washing: The precursor II obtained in step (2) is washed with deionized water, ball-milled and dried to obtain precursor III. Precursor III is washed with water and dried again to obtain Si-SiO-Li2Si2O5 composite material. The pH after washing with deionized water is 6-8. The ball milling speed is 200-300 r / min and the ball milling time is 0.5 h. The pH after washing again is 6-8.

2. The method for preparing silicon suboxide anode material with low energy consumption and high efficiency according to claim 1, characterized in that: In step (1), the lithium source is any one or a combination of at least two of lithium nitrate, lithium hydroxide, or lithium acetate.

3. The method for preparing silicon suboxide anode material with low energy consumption and high efficiency according to claim 1, characterized in that: In step (2), the inert atmosphere is any one or a combination of at least two of nitrogen, argon, helium or neon, and the pressure under the inert atmosphere is -0.1 MPa.

4. The low-energy-consumption and high-efficiency silicon suboxide anode material prepared by the method of claim 1.

5. The application of the low-energy-consumption and high-efficiency silicon suboxide anode material as described in claim 4 in lithium-ion batteries.

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