A method of using a battery or capacitor containing a Sn-based negative electrode

Abstract

This invention discloses a method for using batteries or supercapacitors to improve cycle stability. The method involves using a small current for lithium insertion and a large current for lithium extraction during the lithium insertion / extraction process. This invention can rapidly induce an allotropic transformation from white tin to gray tin during lithium insertion / extraction cycles. Gray tin exhibits smaller volume changes during lithium insertion / extraction compared to white tin, making it less prone to aggregation and thus exhibiting higher cycle stability. Under the lithium insertion / extraction method provided by this invention, a battery containing Sn anode material has an initial charge capacity of 867.8 mAh / g at 30°C and retains 578.7 mAh / g after 200 cycles, with a capacity retention of 66.7%. The lithium insertion / extraction method provided by this invention enables batteries containing Sn anode material to achieve higher capacity, rate performance, and cycle stability.

Description

Technical Field

[0001] This invention belongs to the field of lithium-ion battery technology, specifically relating to a lithium insertion / extraction method for Sn-based materials and its application. Background Technology

[0002] Today, with the widespread use of electronic devices across various industries, there is a growing demand for their energy storage capabilities. Lithium-ion batteries, with their high energy density, long cycle life, and environmental friendliness, have become the ideal medium for energy storage. However, as their applications continue to expand, the shortcomings of traditional lithium-ion batteries are gradually becoming apparent. Problems such as low capacity, poor fast-charging capability, and poor low-temperature performance of commercially available graphite anode materials urgently need to be addressed. Therefore, there is a need to find novel anode materials with high capacity, high lithium-ion diffusion capability, and good low-temperature performance.

[0003] Sn, as a high-capacity anode material, boasts a theoretical capacity of up to 994 mAh / g, far exceeding that of traditional graphite anodes, while also exhibiting good capacity retention at low temperatures. Lithium ions in Sn exhibit extremely high transport rates, allowing for rapid insertion and extraction. However, due to the alloying reaction during lithium insertion and extraction in Sn anodes, a significant volume effect occurs, with an expansion rate reaching 300%, leading to agglomeration and severely impacting cycle stability. While microstructural control of Sn-based anode materials can effectively improve their cycle stability and low-temperature performance, the high cost prevents large-scale commercial production.

[0004] During lithium insertion / extraction cycling, an allotrope α-Sn is formed at the Sn anode. Compared to the pristine β-Sn, α-Sn exhibits a higher diffusion coefficient and impedance, along with better cycle stability. Furthermore, due to the lower lattice density of the α-Sn phase, its volume expansion during lithium alloying is smaller than that of β-Sn (160% vs 300%). During lithium insertion / extraction, the α-Sn and β-Sn phases appear and disappear simultaneously, forming Li. x The presence of Sn indicates that both phases exhibit similar lithium storage processes, thus α-Sn demonstrates better performance as an anode material than β-Sn. α-Sn cannot exist at room temperature and spontaneously transforms into β-Sn, requiring processing of β-Sn to obtain α-Sn. However, this allotropic transformation is difficult to occur under normal charge-discharge conditions, with most Sn remaining as β-Sn and exhibiting aggregation. Therefore, this invention proposes a method to obtain the allotrope of Sn, α-Sn, by controlling the lithium insertion / extraction parameters. The resulting α-Sn anode material exhibits high capacity, high rate capability, high stability, and excellent low-temperature performance. Summary of the Invention

[0005] The purpose of this invention is to overcome the aforementioned shortcomings of the prior art by using a low-current lithium insertion and high-current lithium extraction method to extract lithium from β-Sn materials, achieving complete lithium insertion into Li. 22 The Sn5 phase rapidly extracts lithium, transforming the delithiated Sn into α-Sn. The larger interatomic distance of α-Sn allows for the extraction of lithium from Li. + Diffusion provides more space, and because all atoms are in highly symmetrical positions between the vertices and the center of the tetrahedron, Li + It has more diffusion pathways. The lower lattice density also results in less volume expansion during full lithiation. Therefore, α-Sn theoretically contributes to improving the electrochemical performance of Sn-based anodes.

[0006] To achieve the above-mentioned objective, this invention provides a method for using a battery or supercapacitor with improved cycle stability. The method involves using the battery or supercapacitor containing Sn negative electrode material under conditions of discharging at a low current and charging at a high current. The low-current discharge current density is 0.05–0.2 A / g, and the high-current charging current density is 1.0–10.0 A / g.

[0007] A method for using a battery or supercapacitor to improve cycle stability, employing the following technical solution:

[0008] (1) Preparation of Sn negative electrode: Sn and graphite are used as raw materials for Sn negative electrode material, wherein graphite is uniformly mixed in Sn by stirring.

[0009] The Sn anode material contains 80% to 100% Sn by mass.

[0010] The mass percentage content of graphite in the Sn anode material is 0-20%.

[0011] The method for preparing the Sn negative electrode is as follows:

[0012] 1) Dissolve CMC in deionized water to form a uniform dispersant solution.

[0013] 2) After uniformly mixing Sn powder, graphite powder and conductive carbon black, a dispersant solution is added to form a slurry.

[0014] 3) The mixed slurry is uniformly coated onto the rough surface of a battery-grade Cu foil, and the coated copper foil is dried in a vacuum drying oven at 80°C for 8-12 hours to obtain the Sn negative electrode sheet. Preferably, in the above preparation method, the Sn powder has a purity of 99.99% and a particle size of 100 nm. Preferably, in the above preparation method, the graphite powder has a purity of 99.99%.

[0015] Particle size 5μm.

[0016] In the above preparation method, preferably, the stirring rate is 360 r / min and the time is 10 minutes.

[0017] In the above preparation method, preferably, the thickness of the slurry coating is 5-10 μm.

[0018] In the above preparation method, preferably, the copper foil is battery-grade copper foil, which needs to be cleaned before use to reduce the impact of surface stains and oxides on the material.

[0019] (2) Preparation of batteries containing Sn anode materials

[0020] The dried Sn negative electrode sheet was used as the working electrode for performance testing, and the battery was assembled in a glove box under high-purity Ar environment. A coin cell was assembled using a pure lithium sheet as the counter electrode and a 1M LiPF6-EC:DEC:PC (1:1:1 by vol) electrolyte with 10wt% FEC added.

[0021] (3) Battery usage method

[0022] The assembled button cell battery was charged / discharged under the following conditions: discharge current density of 0.1-0.2 A / g, charging current density of 1.0-10 A / g, and charge / discharge voltage range of 0.01V to 2.0V. The charge / discharge cycle process was as follows: During the first cycle, the battery was first discharged at a constant current to 0.01V, and then charged at a constant current to 2.0V; from the second cycle onwards, the battery was discharged from 2.0V to 0.01V and charged from 0.01V to 2.0V.

[0023] Compared with existing materials and technologies, the advantages of this invention are:

[0024] (1) This invention creatively employs a lithium insertion / extraction method of low-current discharge and high-current charging during battery use, which significantly improves the cycle stability of the battery. This is because the allotropic conversion rate of Sn is greatly increased during the battery use method provided by this invention, thus greatly improving battery performance. The battery prepared under this method has an initial charge specific capacity of 867.8 mAh / g and still retains a capacity of 578.7 mAh / g after 200 cycles, with a capacity retention rate of 66.7%.

[0025] (2) The lithium insertion and extraction method used in the battery of the present invention is simple and can also induce gray tin transformation in pure β-Sn material. The prepared α-Sn structure has high stability and small volume expansion compared with β-Sn, and the stability is greatly improved.

[0026] (3) The α-Sn prepared by this invention has excellent electrochemical performance under normal temperature conditions. Compared with the existing commercial graphite anode, it has extremely high capacity while maintaining extremely high cycle stability.

[0027] (4) The α-Sn prepared by this invention can normally de-intercalate and de-intercalate lithium under low temperature conditions, with small capacity decay, overcoming the disadvantages of low de-intercalation and de-intercalation efficiency and significant capacity reduction of lithium-ion batteries under low temperature conditions. Attached Figure Description

[0028] Figure 1 The X-ray diffraction patterns of Example 2 of the present invention and Comparative Examples 1, 2, and 3 after 50 cycles are shown.

[0029] Figure 2 The graphs show the cycle-specific capacity performance of Embodiments 1, 2, 3, 4, and 5 of the present invention at 30°C.

[0030] Figure 3 This is a graph showing the cycle-specific capacity performance of Example 2 of the present invention and Comparative Examples 1, 2, and 3 at 30°C.

[0031] Figure 4 This is a first charge-discharge curve diagram of Embodiment 1 of the present invention;

[0032] Figure 5 This is the first charge-discharge curve of Embodiment 2 of the present invention;

[0033] Figure 6 This is the first charge-discharge curve of Embodiment 3 of the present invention;

[0034] Figure 7 This is the first charge-discharge curve of Embodiment 4 of the present invention;

[0035] Figure 8 This is the first charge-discharge curve of Embodiment 5 of the present invention;

[0036] Figure 9 These are cycle-specific capacity performance curves of Examples 7, 8, and 10 of the present invention at 30°C.

[0037] Figure 10 This is the first charge-discharge curve of Embodiment 7 of the present invention;

[0038] Figure 11 This is the first charge-discharge curve of Embodiment 8 of the present invention;

[0039] Figure 12 This is the first charge-discharge curve of Embodiment 10 of the present invention;

[0040] Figure 13These are cycle-specific capacity performance curves of Examples 11, 13, and 15 of the present invention at 30°C.

[0041] Figure 14 This is the first charge-discharge curve of Embodiment 11 of the present invention;

[0042] Figure 15 This is the first charge-discharge curve of Embodiment 13 of the present invention;

[0043] Figure 16 This is the first charge-discharge curve of Embodiment 15 of the present invention; Detailed Implementation

[0044] To make the technical problem to be solved, the technical solution, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but the implementation of the present invention is not limited thereto.

[0045] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0046] I. Preparation and Application Examples

[0047] 1. Example 1

[0048] (1) Preparation of batteries containing Sn anode materials

[0049] Sn powder, conductive agent Super-P, and binder CMC were uniformly mixed at a mass ratio of 8:1:1, and then stirred for 30 minutes using a stirrer with deionized water as the solvent to prepare a slurry. The prepared slurry was uniformly coated onto battery-grade copper foil to form an electrode sheet. The electrode sheet was surface-dried using an infrared lamp and then placed in a vacuum drying oven at 80°C for 12 hours. The dried electrode sheet was used as the working electrode for performance testing. Battery assembly was performed in a glove box (Super1220, Shanghai MICARONA Electromechanical Technology Co., Ltd.) with a high-purity Ar environment and an oxygen content of less than 0.01 ppm. Using pure lithium foil as the counter electrode, a coin cell was assembled using 1M LiPF6-EC:DEC:PC (1:1:1 by vol) electrolyte with 10 wt% FEC added.

[0050] (2) Battery charging / discharging use

[0051] The assembled button cell battery was used under the following conditions: discharge current density of 0.2 A / g, charging current density of 1.0 A / g, and charge / discharge voltage range of 0.01 V to 2.0 V. The charge / discharge cycle test process was as follows: During the first cycle, the battery was first discharged at a constant current to 0.01 V, and then charged at a constant current to 2.0 V; starting from the second cycle, the battery was discharged from 2.0 V to 0.01 V and charged from 0.01 V to 2.0 V.

[0052] Under the above battery usage conditions (the battery charge / discharge test system used was the LAND CT2001A battery test system, manufactured by Wuhan Lanhe Electronics Co., Ltd.), if... Figure 2 , 4 As shown, the battery prepared in this embodiment has an initial charge specific capacity of 867.6 mAh / g and still has a capacity of 519.3 mAh / g after 100 cycles, with a capacity retention rate of 59.9%.

[0053] 2. Example 2

[0054] (1) Preparation of batteries containing Sn anode materials

[0055] The preparation steps of the battery containing Sn negative electrode material in this embodiment are the same as those described in step (1) of Example 1.

[0056] (2) Battery charging / discharging use

[0057] The assembled button cells were used under the following conditions for charging / discharging: discharge current density of 0.2 A / g, charging current density of 2.0 A / g, and charge / discharge voltage range of 0.01 V to 2.0 V. The charge / discharge cycle test process was as follows: During the first cycle, the battery was first discharged at a constant current to 0.01 V, and then charged at a constant current to 2.0 V; starting from the second cycle, the battery was discharged from 2.0 V to 0.01 V and charged from 0.01 V to 2.0 V.

[0058] Phase analysis was performed on the Sn anode material prepared in this embodiment after 50 cycles, such as... Figure 1 As shown, a distinct α-Sn peak can be observed, indicating that this charge-discharge method can effectively improve the gray tin conversion efficiency.

[0059] Under the above battery usage conditions (the battery charge / discharge test system used was the LAND CT2001A battery test system, manufactured by Wuhan Lanhe Electronics Co., Ltd.), if... Figure 2 , 5 As shown, the battery prepared in this embodiment has an initial charge specific capacity of 852.3 mAh / g and still has a capacity of 425.9 mAh / g after 150 cycles, with a capacity retention rate of 50.0%.

[0060] 3. Example 3

[0061] (1) Preparation of batteries containing Sn anode materials

[0062] The preparation steps of the battery containing Sn negative electrode material in this embodiment are the same as those described in step (1) of Example 1.

[0063] (2) Battery charging / discharging use

[0064] The assembled button cells were charged and discharged under the following conditions: discharge current density of 0.2 A / g, charging current density of 4.0 A / g, and charge / discharge voltage range of 0.01 V to 2.0 V. The charge / discharge cycle test process was as follows: During the first cycle, the battery was first discharged at a constant current to 0.01 V, and then charged at a constant current to 2.0 V; starting from the second cycle, the battery was discharged from 2.0 V to 0.01 V and charged from 0.01 V to 2.0 V.

[0065] Under the above battery usage conditions (the battery charge / discharge test system used was the LAND CT2001A battery test system, manufactured by Wuhan Lanhe Electronics Co., Ltd.), if... Figure 2 , 6 As shown, the battery prepared in this embodiment has an initial charge specific capacity of 858.0 mAh / g and still has a capacity of 463.5 mAh / g after 200 cycles, with a capacity retention rate of 54.1%.

[0066] 4. Example 4

[0067] (1) Preparation of batteries containing Sn anode materials

[0068] The preparation steps of the battery containing Sn negative electrode material in this embodiment are the same as those described in step (1) of Example 1.

[0069] (2) Battery charging / discharging use

[0070] The assembled button cells were charged and discharged under the following conditions: discharge current density of 0.1 A / g, charging current density of 8.0 A / g, and charge / discharge voltage range of 0.01 V to 2.0 V. The charge / discharge cycle test process was as follows: During the first cycle, the battery was first discharged at a constant current to 0.01 V, and then charged at a constant current to 2.0 V; starting from the second cycle, the battery was discharged from 2.0 V to 0.01 V and charged from 0.01 V to 2.0 V.

[0071] Under the above battery usage conditions (the battery charge / discharge test system used was the LAND CT2001A battery test system, manufactured by Wuhan Lanhe Electronics Co., Ltd.), if... Figure 2 , 7 As shown, the battery prepared in this embodiment has an initial charge specific capacity of 824.7 mAh / g and still has a capacity of 467.2 mAh / g after 200 cycles, with a capacity retention rate of 56.7%.

[0072] 5. Example 5

[0073] (1) Preparation of batteries containing Sn anode materials

[0074] The preparation steps of the battery containing Sn negative electrode material in this embodiment are the same as those described in step (1) of Example 1.

[0075] (2) Battery charging / discharging use

[0076] The assembled button cells were charged and discharged under the following conditions: discharge current density of 0.2 A / g, charging current density of 10.0 A / g, and charge / discharge voltage range of 0.01 V to 2.0 V. The charge / discharge cycle test process was as follows: During the first cycle, the battery was first discharged at a constant current to 0.01 V, and then charged at a constant current to 2.0 V; from the second cycle onwards, the battery was discharged from 2.0 V to 0.01 V and charged from 0.01 V to 2.0 V.

[0077] Under the above battery usage conditions (the battery charge / discharge test system used was the LAND CT2001A battery test system, manufactured by Wuhan Lanhe Electronics Co., Ltd.), if... Figure 2 , 8 As shown, the battery prepared in this embodiment has an initial charge specific capacity of 819.6 mAh / g and still has a capacity of 459.9 mAh / g after 200 cycles, with a capacity retention rate of 56.1%.

[0078] 6. Example 6

[0079] (1) Preparation of batteries containing Sn anode materials

[0080] The preparation steps of the battery containing Sn anode material in this embodiment are basically the same as those described in step (1) of Example 1. The difference is that commercial graphite is added to the initial Sn powder, and the ratio of Sn to graphite is 90%:10%.

[0081] (2) Battery charging / discharging use

[0082] The assembled button cells were charged and discharged under the following conditions: discharge current density of 0.1 A / g, charging current density of 1.0 A / g, and charge / discharge voltage range of 0.01 V to 2.0 V. The charge / discharge cycle test process was as follows: During the first cycle, the battery was first discharged at a constant current to 0.01 V, and then charged at a constant current to 2.0 V; starting from the second cycle, the battery was discharged from 2.0 V to 0.01 V and charged from 0.01 V to 2.0 V.

[0083] Under the above battery usage conditions (the battery charge / discharge test system used was a LAND CT2001A battery test system, Wuhan Lanhe Electronics Co., Ltd.), the battery prepared in this embodiment had an initial charge specific capacity of 864.7 mAh / g and a capacity of 449.7 mAh / g after 200 cycles, with a capacity retention rate of 52.0%.

[0084] 7. Example 7

[0085] (1) Preparation of batteries containing Sn anode materials

[0086] The preparation steps of the battery containing Sn anode material in this embodiment are the same as those described in step (1) of embodiment 6.

[0087] (2) Battery charging / discharging use

[0088] The assembled button cells were charged and discharged under the following conditions: discharge current density of 0.1 A / g, charging current density of 2.0 A / g, and charge / discharge voltage range of 0.01 V to 2.0 V. The charge / discharge cycle test process was as follows: During the first cycle, the battery was first discharged at a constant current to 0.01 V, and then charged at a constant current to 2.0 V; starting from the second cycle, the battery was discharged from 2.0 V to 0.01 V and charged from 0.01 V to 2.0 V.

[0089] Under the above battery usage conditions (the battery charge / discharge test system used was the LAND CT2001A battery test system, manufactured by Wuhan Lanhe Electronics Co., Ltd.), if... Figure 9 , 10 As shown, the battery prepared in this embodiment has an initial charge specific capacity of 876.1 mAh / g and still has a capacity of 456.9 mAh / g after 200 cycles, with a capacity retention rate of 52.2%.

[0090] 8. Example 8

[0091] (1) Preparation of batteries containing Sn anode materials

[0092] The preparation steps of the battery containing Sn anode material in this embodiment are the same as those described in step (1) of embodiment 6.

[0093] (2) Battery charging / discharging use

[0094] The assembled button cells were charged and discharged under the following conditions: discharge current density of 0.1 A / g, charging current density of 4.0 A / g, and charge / discharge voltage range of 0.01 V to 2.0 V. The charge / discharge cycle test process was as follows: During the first cycle, the battery was first discharged at a constant current to 0.01 V, and then charged at a constant current to 2.0 V; starting from the second cycle, the battery was discharged from 2.0 V to 0.01 V and charged from 0.01 V to 2.0 V.

[0095] Under the above battery usage conditions (the battery charge / discharge test system used was the LAND CT2001A battery test system, manufactured by Wuhan Lanhe Electronics Co., Ltd.), if... Figure 9 , 11 As shown, the battery prepared in this embodiment has an initial charge specific capacity of 867.8 mAh / g and still has a capacity of 578.7 mAh / g after 200 cycles, with a capacity retention rate of 66.7%.

[0096] 9. Example 9

[0097] (1) Preparation of batteries containing Sn anode materials

[0098] The preparation steps of the battery containing Sn anode material in this embodiment are the same as those described in step (1) of embodiment 6.

[0099] (2) Battery charging / discharging use

[0100] The assembled button cells were charged and discharged under the following conditions: discharge current density of 0.1 A / g, charging current density of 8.0 A / g, and charge / discharge voltage range of 0.01 V to 2.0 V. The charge / discharge cycle test process was as follows: During the first cycle, the battery was first discharged at a constant current to 0.01 V, and then charged at a constant current to 2.0 V; starting from the second cycle, the battery was discharged from 2.0 V to 0.01 V and charged from 0.01 V to 2.0 V.

[0101] Under the above battery usage conditions (the battery charge / discharge test system used was a LAND CT2001A battery test system, Wuhan Lanhe Electronics Co., Ltd.), the battery prepared in this embodiment had an initial charge specific capacity of 857.2 mAh / g and a capacity of 566.1 mAh / g after 200 cycles, with a capacity retention rate of 66.0%.

[0102] 10. Example 10

[0103] (1) Preparation of batteries containing Sn anode materials

[0104] The preparation steps of the battery containing Sn anode material in this embodiment are the same as those described in step (1) of embodiment 6.

[0105] (2) Battery charging / discharging use

[0106] The assembled button cells were used under the following conditions for charging / discharging: discharge current density of 0.1 A / g, charging current density of 10.0 A / g, and charge / discharge voltage range of 0.01 V to 2.0 V. The charge / discharge cycle test process was as follows: During the first cycle, the battery was first discharged at a constant current to 0.01 V, and then charged at a constant current to 2.0 V; starting from the second cycle, the battery was discharged from 2.0 V to 0.01 V and charged from 0.01 V to 2.0 V.

[0107] Under the above battery usage conditions (the battery charge / discharge test system used was the LAND CT2001A battery test system, manufactured by Wuhan Lanhe Electronics Co., Ltd.), if... Figure 9 , 12 As shown, the battery prepared in this embodiment has an initial charge specific capacity of 873.4 mAh / g and still has a capacity of 533.6 mAh / g after 200 cycles, with a capacity retention rate of 61.1%.

[0108] 11. Example 11

[0109] (1) Preparation of batteries containing Sn anode materials

[0110] The preparation steps of the battery containing Sn anode material in this embodiment are basically the same as those described in step (1) of Example 1. The difference is that commercial graphite is added to the initial Sn powder, and the ratio of Sn to graphite is 80%:20%.

[0111] (2) Battery charging / discharging use

[0112] The assembled button cells were charged and discharged under the following conditions: discharge current density of 0.2 A / g, charging current density of 1.0 A / g, and charge / discharge voltage range of 0.01 V to 2.0 V. The charge / discharge cycle test process was as follows: During the first cycle, the battery was first discharged at a constant current to 0.01 V, and then charged at a constant current to 2.0 V; starting from the second cycle, the battery was discharged from 2.0 V to 0.01 V and charged from 0.01 V to 2.0 V.

[0113] Under the above battery usage conditions (the battery charge / discharge test system used was the LAND CT2001A battery test system, manufactured by Wuhan Lanhe Electronics Co., Ltd.), if... Figure 13 ,14 As shown, the battery prepared in this embodiment has an initial charge specific capacity of 684.2 mAh / g and retains a capacity of 431.9 mAh / g after 100 cycles, with a capacity retention rate of 63.1%.

[0114] 12. Example 12

[0115] (1) Preparation of batteries containing Sn anode materials

[0116] The preparation steps of the battery containing Sn negative electrode material in this embodiment are the same as those described in step (1) of Example 11.

[0117] (2) Battery charging / discharging use

[0118] The assembled button cells were charged and discharged under the following conditions: discharge current density of 0.2 A / g, charging current density of 2.0 A / g, and charge / discharge voltage range of 0.01 V to 2.0 V. The charge / discharge cycle test process was as follows: During the first cycle, the battery was first discharged at a constant current to 0.01 V, and then charged at a constant current to 2.0 V; from the second cycle onwards, the battery was discharged from 2.0 V to 0.01 V and charged from 0.01 V to 2.0 V.

[0119] Under the above battery usage conditions (the battery charge / discharge test system used was a LAND CT2001A battery test system, Wuhan Lanhe Electronics Co., Ltd.), the battery prepared in this embodiment had an initial charge specific capacity of 688.1 mAh / g and a capacity of 475.1 mAh / g after 100 cycles, with a capacity retention rate of 69.1%.

[0120] 13. Example 13

[0121] (1) Preparation of batteries containing Sn anode materials

[0122] The preparation steps of the battery containing Sn negative electrode material in this embodiment are the same as those described in step (1) of Example 11.

[0123] (2) Battery charging / discharging use

[0124] The assembled button cells were charged and discharged under the following conditions: discharge current density of 0.2 A / g, charging current density of 4.0 A / g, and charge / discharge voltage range of 0.01 V to 2.0 V. The charge / discharge cycle test process was as follows: During the first cycle, the battery was first discharged at a constant current to 0.01 V, and then charged at a constant current to 2.0 V; starting from the second cycle, the battery was discharged from 2.0 V to 0.01 V and charged from 0.01 V to 2.0 V.

[0125] Under the above battery usage conditions (the battery charge / discharge test system used was the LAND CT2001A battery test system, manufactured by Wuhan Lanhe Electronics Co., Ltd.), if... Figure 13 , 15 As shown, the battery prepared in this embodiment has an initial charge specific capacity of 691.4 mAh / g and still has a capacity of 417.1 mAh / g after 200 cycles, with a capacity retention rate of 60.0%.

[0126] 14. Example 14

[0127] (1) Preparation of batteries containing Sn anode materials

[0128] The preparation steps of the battery containing Sn negative electrode material in this embodiment are the same as those described in step (1) of Example 11.

[0129] (2) Battery charging / discharging use

[0130] The assembled button cells were charged and discharged under the following conditions: discharge current density of 0.2 A / g, charging current density of 8.0 A / g, and charge / discharge voltage range of 0.01 V to 2.0 V. The charge / discharge cycle test process was as follows: During the first cycle, the battery was first discharged at a constant current to 0.01 V, and then charged at a constant current to 2.0 V; starting from the second cycle, the battery was discharged from 2.0 V to 0.01 V and charged from 0.01 V to 2.0 V.

[0131] Under the above battery usage conditions (the battery charge / discharge test system used was a LAND CT2001A battery test system, Wuhan Lanhe Electronics Co., Ltd.), the battery prepared in this embodiment had an initial charge specific capacity of 679.7 mAh / g and a capacity of 422.6 mAh / g after 200 cycles, with a capacity retention rate of 62.2%.

[0132] 15. Example 15

[0133] (1) Preparation of batteries containing Sn anode materials

[0134] The preparation steps of the battery containing Sn negative electrode material in this embodiment are the same as those described in step (1) of Example 11.

[0135] (2) Battery charging / discharging use

[0136] The assembled button cells were charged and discharged under the following conditions: discharge current density of 0.2 A / g, charging current density of 10.0 A / g, and charge / discharge voltage range of 0.01 V to 2.0 V. The charge / discharge cycle test process was as follows: During the first cycle, the battery was first discharged at a constant current to 0.01 V, and then charged at a constant current to 2.0 V; starting from the second cycle, the battery was discharged from 2.0 V to 0.01 V and charged from 0.01 V to 2.0 V.

[0137] Under the above battery usage conditions (the battery charge / discharge test system used was the LAND CT2001A battery test system, manufactured by Wuhan Lanhe Electronics Co., Ltd.), if... Figure 13 , 16 As shown, the battery prepared in this embodiment has an initial charge specific capacity of 671.3 mAh / g and still has a capacity of 447.6 mAh / g after 200 cycles, with a capacity retention rate of 66.7%.

[0138] II. Comparative Examples

[0139] 1. Comparative Example 1

[0140] (1) Preparation of batteries containing Sn anode materials

[0141] The preparation steps of the battery containing Sn negative electrode material in this embodiment are the same as those described in step (1) of Example 1.

[0142] (2) Battery charging / discharging use

[0143] The assembled button cells were charged and discharged under the following conditions: discharge current density of 0.2 A / g, charging current density of 0.2 A / g, and charge / discharge voltage range of 0.01 V to 2.0 V. The charge / discharge cycle test process was as follows: During the first cycle, the battery was first discharged at a constant current to 0.01 V, and then charged at a constant current to 2.0 V; starting from the second cycle, the battery was discharged from 2.0 V to 0.01 V and charged from 0.01 V to 2.0 V.

[0144] The battery was tested under the conditions described above (the battery charge / discharge test system used was the LAND CT2001A battery test system, manufactured by Wuhan Lanhe Electronics Co., Ltd.). For example... Figure 1 , 2 As shown in Figure 3, under room temperature conditions, the battery capacity decays to less than 150 mAh / g after 40 cycles, which is much lower than that of the Sn anode material in Example 2.

[0145] 2. Comparative Example 2

[0146] (1) Preparation of batteries containing Sn anode materials

[0147] The preparation steps of the battery containing Sn negative electrode material in this embodiment are the same as those described in step (1) of Example 1.

[0148] (2) Battery charging / discharging use

[0149] The assembled button cells were charged and discharged under the following conditions: discharge current density of 2.0 A / g, charging current density of 0.2 A / g, and charge / discharge voltage range of 0.01 V to 2.0 V. The charge / discharge cycle test process was as follows: During the first cycle, the battery was first discharged at a constant current to 0.01 V, and then charged at a constant current to 2.0 V; from the second cycle onwards, the battery was discharged from 2.0 V to 0.01 V and charged from 0.01 V to 2.0 V.

[0150] The battery was tested under the conditions described above (the battery charge / discharge test system used was the LAND CT2001A battery test system, manufactured by Wuhan Lanhe Electronics Co., Ltd.). For example... Figure 1 , 3 As shown, at room temperature, the battery capacity decays to less than 100 mAh / g after 40 cycles, which is much lower than that of the battery in Example 2.

[0151] 3. Comparative Example 2

[0152] (1) Preparation of batteries containing Sn anode materials

[0153] The preparation steps of the battery containing Sn negative electrode material in this embodiment are the same as those described in step (1) of Example 1.

[0154] (2) Battery charging / discharging use

[0155] The assembled button cells were charged and discharged under the following conditions: discharge current density of 2.0 A / g, charging current density of 2.0 A / g, and charge / discharge voltage range of 0.01 V to 2.0 V. The charge / discharge cycle test process was as follows: During the first cycle, the battery was first discharged at a constant current to 0.01 V, and then charged at a constant current to 2.0 V; starting from the second cycle, the battery was discharged from 2.0 V to 0.01 V and charged from 0.01 V to 2.0 V.

[0156] The battery was tested under the conditions described above (the battery charge / discharge test system used was the LAND CT2001A battery test system, manufactured by Wuhan Lanhe Electronics Co., Ltd.). For example... Figure 1 , 3 As shown, at room temperature, the battery capacity decays to less than 200 mAh / g after 40 cycles, which is much lower than that of the battery in Example 2.

[0157] A comparison between Example 2 and the comparative example shows that the α-Sn after gray tin transformation is superior to the original β-Sn.

[0158] It exhibits better cycle stability and low-temperature performance. α-Sn anode materials demonstrate excellent performance in terms of high first-efficiency, high coulombic efficiency, high rate capability, and high cycle stability.

[0159] As described above, the present invention can be well implemented. The above embodiments are only some embodiments of the present invention and are not intended to limit the scope of implementation of the present invention; that is, all equivalent changes and modifications made in accordance with the content of the present invention are covered by the scope of protection claimed in the claims of the present invention.

Claims

1. A method of using a battery or supercapacitor with improved cycling stability, characterized in that, It comprises the following steps: (1) Preparation of Sn negative electrode sheet: Sn and graphite are used as Sn negative electrode material, wherein the graphite is uniformly mixed in Sn by stirring slurry; The Sn negative electrode sheet is prepared by the following method: CMC is dissolved in deionized water to form a uniform dispersant solution; Sn powder, graphite powder and conductive carbon black are uniformly mixed and then added to the dispersant solution to form a slurry; The mixed slurry is uniformly coated on the rough surface of the battery-grade copper foil, and the coated copper foil is dried in a vacuum drying oven at 80℃ for 8-12h to obtain the Sn negative electrode sheet; (2) Preparation of Sn-containing negative electrode material battery The dried Sn negative electrode sheet is used as the working electrode, pure lithium sheet is used as the counter electrode, electrolyte is added, and the battery is assembled; (3) Method for using the battery The battery assembled above is used for charging / discharging under the following conditions: the discharge current density is 0.05~0.2A / g, the charge current density is 1.0~10.0A / g, and the charge / discharge voltage range is 0.01 V~2.0 V; The charge / discharge cycle process is as follows: in the first cycle, the battery is first discharged at a constant current to 0.01 V, and then charged at a constant current to 2.0 V; from the second cycle, the battery is discharged from 2.0 V to 0.01 V, and charged from 0.01 V to 2.0 V.

2. The use of a battery or supercapacitor with improved cycling stability according to claim 1, characterized in that, The purity of the Sn powder is 99.99%, and the particle size is 100 nm; the purity of the graphite powder is 99.99%, and the particle size is 5 μm; the stirring rate of the slurry is 360 r / min, the time is 10 minutes, the thickness of the slurry coating is 5~10 μm, and the copper foil is a battery-grade copper foil which needs to be cleaned before use to reduce the impact of surface stains and oxides on the material.

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