Method for preparing high-rate dual-ion battery electrode by using waste graphite

Abstract

The invention discloses a method for preparing a high-rate dual-ion battery electrode by weakening Van der Waals' force between graphite layers by using waste graphite as a raw material, which is characterized in that the waste graphite is treated by a simple mechanical physical method, and the Van der Waals' force between the graphite layers is weakened; therefore, the graphite material which is improved in performance and can be used for a high-rate dual-ion battery electrode is obtained. The method provided by the invention has the following advantages: Van der Waals force between graphite layers is weakened, the intercalation potential barrier of anions is reduced, and the rate characteristic of the dual-ion battery is optimized; the volume expansion of graphite in the anion intercalation process is reduced, so that the cycling stability of the dual-ion battery is improved; and the recycling cost of the waste graphite is reduced.

Description

Technical Field

[0001] The present invention belongs to the field of battery materials, and specifically relates to a method for preparing a graphite material with improved performance that can be used for high-rate dual-ion battery electrodes, by treating waste graphite through simple mechanical and physical methods to weaken the van der Waals forces between graphite layers. Background Art

[0002] Dual-ion battery technology usually uses graphite as the positive electrode, which has an anion-cation synergistic redox energy storage mechanism. In addition, the anion intercalation / extraction reaction usually occurs at a higher potential (4.5V.vs Li+ / Li). Therefore, in theory, dual-ion battery technology has the advantages of good power characteristics, good energy density, and low cost. However, traditional graphite positive electrodes usually show poor cycle stability due to their small interlayer spacing. The graphite negative electrode material of discarded lithium-ion batteries shows an increase in the interlayer spacing of graphite due to the destruction of the interlayer van der Waals force to a certain extent during service, which makes it more suitable as a dual-ion battery positive electrode in theory. However, the graphite interlayer of discarded graphite still has a strong van der Waals force, which affects the intercalation kinetics of anions and the cycle stability of the battery.

[0003] At present, the treatment of waste graphite in the prior art is generally divided into two ways, one of which is to repair the graphene layer defects of the discarded graphite by high-temperature annealing, such as the method in the document (Advanced cathode for dual-ion batteries: Waste-to-wealth reuse of spent graphite from lithium-ion batteries, Jia-Lin Yang et al., eScience2(2022)95-101); the second is to use chemically inert materials (for example, Chinese invention patent publications CN114188521A and CN114430029A) to coat the surface of conventional graphite with other materials to form a core-shell structure to improve the interfacial stability of the graphite positive electrode in the dual-ion battery, thereby improving its electrochemical performance as the positive electrode material of the dual-ion battery.

[0004] However, the above existing technologies suffer from the following insurmountable technical drawbacks: 1) High-temperature calcination of retired graphite is energy-intensive and costly. 2) While surface coating methods improve the electrochemical performance of graphite cathodes by optimizing the interface structure and ion transport kinetics at the interface, they do not address the transport of anions within the bulk graphite phase, resulting in poor electrochemical performance under fast-charging conditions.

[0005] Therefore, there is still a need to find more effective and inexpensive ways to reuse waste graphite materials. Summary of the Invention

[0006] In response to the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a method for preparing high-rate dual-ion battery electrodes using waste graphite. This method treats waste graphite from lithium-ion batteries through simple mechanical and physical methods to weaken the van der Waals forces between graphite layers, thereby obtaining a graphite material with improved performance that can be used for high-rate dual-ion battery electrodes.

[0007] According to one aspect of the present invention, an object of the present invention is to provide a method for preparing a high-rate dual-ion battery electrode using waste graphite, the method comprising the following steps:

[0008] Step 1. Add waste graphite positive electrode material to deionized water, stir and disperse evenly, and then ultrasonically treat for 0.5-2h. Vacuum filter and dry the pretreated graphite positive electrode material. The interlayer spacing of the waste graphite positive electrode material is 0.336nm±0.001nm.

[0009] Step 2. Place the pretreated graphite material and zirconia balls in a ball mill at a mass ratio of 1:30 to 1:10 and mill for 1-12 hours to obtain graphite with weakened van der Waals force.

[0010] Step 3. Graphite that weakens van der Waals forces is mixed with a conductive agent and a binder in a dispersant at a mass ratio of 8:1:1, then evenly coated on the current collector, baked at 80°C for 12 hours, and cut into the desired shape to form a high-rate dual-ion battery positive electrode.

[0011] Preferably, the purpose of ultrasonic treatment in step 1 is to remove possible impurities (such as metallic lithium or graphite-level LiC x The treatment time is preferably 0.5-2h. If the time is less than 0.5h, it may have an adverse effect on the subsequent ball milling process; when the treatment time exceeds 2h, some graphite particles may be damaged or even the graphite layer may be peeled off. At the same time, based on economic considerations, the treatment time is selected not to exceed 2h.

[0012] Preferably, the mass ratio of the pretreated graphite material to the zirconia balls in step 2 is further preferably 1:25 to 1:15, more preferably 1:20. When the mass ratio of the graphite material to the zirconia balls is less than 1:10, the zirconia balls cannot fully contact the graphite material during ball milling, and a relatively uniform particle size cannot be obtained. However, when the mass ratio of the graphite material to the zirconia balls is greater than 1:30, the graphite material is subjected to excessive shear force during ball milling, resulting in excessive defects in the graphite material and affecting ion storage performance.

[0013] Preferably, the ball milling time in step 2 is preferably 2-8 hours, more preferably 3-6 hours. When the ball milling time is less than 2 hours, the graphite material is not fully ball milled, and the obtained graphite material particles are uneven in size. When the ball milling time is greater than 6 hours, the obtained graphite material is too small, resulting in an increase in specific surface area and defects, which has a negative impact on the electrochemical performance of the battery.

[0014] Preferably, the diameter of the zirconia balls used in step 2 is 3 mm. If the diameter of the zirconia balls is too small, the resulting graphite particles are too small, surface defects increase, and the stability of the graphite material under high voltage conditions decreases. If the diameter of the zirconia balls is too large, the contact area between the grinding balls and the graphite is reduced, making it impossible to fully ball mill.

[0015] Preferably, the particle size of the graphite with weakened van der Waals force obtained in step 2 is 5-10 μm, and the interlayer spacing of the graphite with weakened van der Waals force is 0.339-0.348 nm.

[0016] According to another aspect of the present invention, another object of the present invention is to provide a high-rate dual-ion battery, wherein the high-rate dual-ion battery uses the electrode prepared by the present invention as a positive electrode.

[0017] Beneficial effects

[0018] Compared with existing dual-ion positive electrode graphite materials, the present invention has the following advantages:

[0019] 1. Weaken the van der Waals force between graphite layers, reduce the intercalation barrier of anions, and optimize the rate characteristics of dual-ion batteries.

[0020] 2. Reduce the volume expansion of graphite during anion intercalation, thereby improving the cycle stability of dual-ion batteries.

[0021] 3. Reduce the cost of recycling waste graphite. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 XRD spectra of graphite materials obtained using different embodiments / comparative examples.

[0024] Figure 2 HRTEM images of the graphite materials obtained in Example 1 and Comparative Example 1.

[0025] Figure 3 SEM images of graphite materials obtained using different examples / comparative examples.

[0026] Figure 4 Raman spectra of graphite materials obtained using different embodiments / comparative examples.

[0027] Figure 5 Rate performance of dual-ion batteries using the graphite materials of different embodiments / comparative embodiments as the positive electrode.

[0028] Figure 6 Cycling test of dual-ion batteries using the graphite materials of different embodiments / comparative embodiments as the positive electrode.

[0029] Figure 7 Rate performance of dual-ion batteries using the graphite materials of different Examples 4 as positive electrodes.

[0030] Figure 8 Cycling test of a dual-ion battery using the graphite material of different Example 4 as the positive electrode.

[0031] Figure 9 Rate performance of dual-ion batteries using the graphite materials of different embodiments 5 as the positive electrode.

[0032] Figure 10 Cycling test of a dual-ion battery using the graphite material of different Example 5 as the positive electrode.

[0033] Figure 11 Rate performance of dual-ion batteries using the graphite materials of different Examples 6 as positive electrodes.

[0034] Figure 12 Cycling test of a dual-ion battery using the graphite material of different Example 6 as the positive electrode.

[0035] Figure 13 Rate performance of dual-ion batteries using the graphite materials of different comparative examples 3 as positive electrodes.

[0036] Figure 14 Cycling test of a dual-ion battery using the graphite material of different Example 3 as the positive electrode.

[0037] Figure 15 Cycling test of a dual-ion battery using the graphite material of different Example 4 as the positive electrode.

[0038] Figure 16 Rate performance of dual-ion batteries using the graphite materials of different comparative examples 5 as positive electrodes.

[0039] Figure 17Cycling test of a dual-ion battery using the graphite material of different comparative examples 5 as the positive electrode.

[0040] Figure 18 Rate performance of dual-ion batteries using the graphite materials of different comparative examples 6 as positive electrodes.

[0041] Figure 19 Cycling test of a dual-ion battery using the graphite material of different comparative examples 6 as the positive electrode. DETAILED DESCRIPTION

[0042] The present invention will be described in detail below. Before describing, it should be understood that the terms used in this specification and the appended claims should not be interpreted as limited to the general meaning and dictionary meaning, but should be interpreted according to the meaning and concept corresponding to the technical aspects of the present invention on the basis of the principle that allows the inventor to appropriately define the terms for the best interpretation. Therefore, the descriptions presented here are merely preferred examples for illustrative purposes and are not intended to limit the scope of the present invention. It should be understood that other equivalents or improvements can be obtained therefrom without departing from the spirit and scope of the present invention.

[0043] As used herein, the terms "comprises," "includes," "has," "contains" or any other similar terms are open conjunctions that are intended to cover non-exclusive inclusions. For example, a composition or article containing multiple elements is not limited to the elements listed herein, but may also include other elements that are not explicitly listed but are generally inherent to the composition or article. In addition, unless expressly stated to the contrary, the term "or" refers to an inclusive "or" rather than an exclusive "or." For example, any of the following situations satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist), A is false (or does not exist) and B is true (or exists), and both A and B are true (or exist). In addition, as used herein, the terms "comprises," "includes," "has," and "contains" should be interpreted as specifically disclosed and simultaneously cover closed or semi-closed conjunctions such as "consisting of" and "consisting essentially of."

[0044] Throughout this document, all features or conditions defined as numerical ranges or percentage ranges are for simplicity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered to encompass and specifically disclose all possible subranges and individual values ​​within those ranges, particularly integer values. For example, a description of a range "1 to 8" should be considered to specifically disclose all possible subranges such as 1 to 7, 2 to 8, 2 to 6, 3 to 6, 4 to 8, 3 to 8, and so forth, particularly those defined by all integer values, and should be considered to specifically disclose individual values ​​within those ranges such as 1, 2, 3, 4, 5, 6, 7, and 8. Unless otherwise indicated, the foregoing interpretation applies to all of the present disclosure, regardless of whether the ranges are comprehensive or not.

[0045] If a quantity or other value or parameter is expressed as a range, a preferred range, or a series of upper and lower limits, it should be understood that all ranges consisting of any upper limit or preferred value of the range and any lower limit or preferred value of the range have been specifically disclosed herein, regardless of whether these ranges are disclosed separately. In addition, when a numerical range is mentioned herein, unless otherwise specified, the range should include its endpoints and all integers and fractions within the range.

[0046] In this document, numerical values ​​should be understood to have the accuracy of the number of significant digits of the numerical value, provided that the purpose of the invention can be achieved. For example, the number 40.0 should be understood to cover the range from 39.50 to 40.49.

[0047] In addition, unless otherwise stated, the reagents and solvents disclosed below were purchased from Dongguan Canrd New Energy Technology Co., Ltd. (Canrd New Energy Technology); waste graphite materials were disassembled from retired lithium-ion batteries. The phase structure of the materials was measured using an X-ray diffractometer (XRD) of the Rigaku SmartLab SE model; Raman spectra were obtained on a Raman spectrometer of the Renishaw model; images of the micromorphology of the graphite materials were obtained on an Apreo 2C Hivac field emission scanning electron microscope (SEM), and the interlayer spacing of these graphite materials was observed on a Talos F200X G2 field emission transmission electron microscope. The cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) of the dual-ion battery were recorded on an electrochemical workstation (CHI760E), and constant current charge and discharge and long cycle tests at different current densities were performed on a blue battery test system (LAND CT2001A).

[0048] When graphite is used as a battery electrode, its interlayer spacing significantly impacts the performance of high-rate batteries. For example, in lithium-ion batteries, the interlayer spacing of the graphite anode directly influences the transport pathways for lithium ions within the electrode material. Furthermore, a suitable interlayer spacing helps maintain the structural stability of the graphite electrode during charge and discharge. A larger interlayer spacing provides a more spacious transport pathway for lithium ions, enabling faster insertion and removal of lithium ions from the graphite electrode, thereby improving the battery's charge and discharge rate performance and enabling high-rate cycling and fast charging. Increasing the interlayer spacing from 0.335nm to 0.37nm increases the diffusion coefficient of lithium ions between graphite layers by an order of magnitude, significantly accelerating lithium ion transport. However, excessively large interlayer spacing can weaken the interaction between graphite layers, making the layered structure prone to collapse or exfoliation during repeated insertion and removal of lithium ions, thereby reducing the battery's cycle life and charge and discharge performance. Conversely, a smaller interlayer spacing makes lithium ion insertion and removal difficult, also compromising the battery's high-rate performance.

[0049] When graphite material is used as the positive electrode material of a dual-ion battery, the interlayer spacing of the graphite also needs to be controlled within a certain range to achieve high-rate battery cycling and fast charging, while ensuring rapid anion transport and maintaining the stability of the graphite structure.

[0050] The following examples are merely examples of embodiments of the present invention and do not constitute any limitation thereto. Those skilled in the art will appreciate that modifications without departing from the spirit and scope of the present invention fall within the scope of protection of the present invention. Unless otherwise specified, the reagents and instruments used in the following examples are commercially available products.

[0051] Example 1

[0052] 1g of waste graphite and other cathode materials were placed in 300mL of deionized water, magnetically stirred and dispersed evenly, and then ultrasonically treated for 1h. After vacuum filtration and drying, the pretreated graphite cathode material had an interlayer spacing of about 0.336nm. The pretreated graphite material and zirconia balls were placed in a ball mill at a mass ratio of 1:20 and ball milled for 6h to obtain graphite with weakened van der Waals force, such as Figure 1 As shown in FIG, with the increase of ball milling time, the (002) peak position of these graphite materials shifts to a low angle; among them, the interlayer spacings of Comparative Example 1 (waste graphite material), Comparative Example 2, Example 3, Example 1, and Example 2 are 0.336, 0.339, 0.342, 0.346, and 0.348 nm, respectively, which is consistent with the Figure 2 The HRTEM image results are consistent with those in . Figure 3 The SEM images in Figure 3 show that the thickness of the graphite material decreases significantly with increasing ball milling time. Figure 4Raman spectroscopy in Figure 2 shows that the intensity of the graphite's D peak (representing disordered carbon atoms) increases with ball milling time, indicating an increase in defects. These results demonstrate that the shear forces applied to the graphite during ball milling weaken the van der Waals forces between the graphite layers, leading to an increase in the interlayer spacing. Notably, increasing ball milling time also results in a decrease in graphite size and an increase in defect concentration.

[0053] Electrode preparation: Graphite material, conductive agent Super P, and binder polyvinylidene fluoride were uniformly mixed in a dispersant N-methylpyrrolidone at a mass ratio of 8:1:1. The mixture was then coated on aluminum foil, baked at 80°C for 12 hours, and cut into discs with a diameter of 10 mm for later use.

[0054] Preparation of dual-ion batteries: R2032 button cells were assembled using the graphite electrode prepared in this example, lithium metal, and 4M LiPF6 / EMC as the positive electrode, negative electrode, and electrolyte, respectively. All cells were allowed to rest for 6 hours before electrochemical testing. Galvanostatic charge-discharge (GCD) was used to test rate performance (e.g., 2, 4, 6, 8, 10, and 20 C) and long-cycle stability.

[0055] like Figure 5-6 As shown, compared with other embodiments / comparative embodiments, the graphite material obtained in this embodiment exhibits the best comprehensive performance, such as the discharge capacity at 2, 4, 6, 8, 10, and 20C rates of 84, 83, 81, 79, 77, and 65 mAh / g, respectively, indicating that weakening the van der Waals force significantly improves the rate performance of the graphite positive electrode; at the same time, the graphite positive electrode exhibits excellent cycle stability, and the capacity retention rate is as high as 86.7% after 1000 charge and discharge cycles at 5C.

[0056] Example 2

[0057] Compared with Example 1, the ball milling time in this example was changed to 3 hours, and other conditions remained unchanged. The interlayer spacing of the obtained graphite material was 0.342nm. Figure 5-6 As shown, the positive electrode material obtained in this embodiment exhibits good rate performance, with discharge capacities of 86, 82, 74, 55, 49, and 33 mAh / g at rates of 2, 4, 6, 8, 10, and 20 C, respectively; and in the charge and discharge test at 5 C, the first 300 cycles show good stability.

[0058] Example 3

[0059] Compared with Example 1, the ball milling time in this example was changed to 12 h, and other conditions remained unchanged. The interlayer spacing of the obtained graphite material was 0.348 nm. Figure 5-6As shown, the rate performance of the graphite positive electrode material obtained in this embodiment is poor, and the discharge capacity at 2, 4, 6, 8, 10, and 20C rates is 74, 61, 48, 44, 39, and 15 mAh / g, respectively, indicating that too many defects will affect the intercalation kinetics of anions; it is worth noting that it shows excellent stability in the cycle test at 5C, and the capacity retention rate after 1000 charge and discharge cycles is as high as 86.2%.

[0060] Example 4

[0061] Compared with Example 1, the mass ratio of graphite material to zirconia ball in this embodiment is 1:10, and other conditions remain unchanged. The interlayer spacing of the obtained graphite material is 0.344nm. Figure 7-8 As shown in the figure, the graphite positive electrode material obtained in this embodiment exhibits poor rate performance, with discharge capacities of 83, 67, 50, 44, 38, and 10 mAh / g at rates of 2, 4, 6, 8, 10, and 20 C, respectively; the cycle stability at 5 C is excellent, with a capacity retention rate of up to 88.1% after 1000 charge and discharge cycles.

[0062] Example 5

[0063] Compared with Example 1, the graphite material in this example is changed to natural graphite (NG), and other conditions remain unchanged. The interlayer spacing of the obtained graphite material is 0.341nm. Figure 9-10 As shown, the graphite cathode material obtained in this example exhibits significantly better rate performance than the unmodified NG cathode. Meanwhile, the NG cathode material exhibits poor cycling stability at 10C, experiencing a cliff-like capacity decay in the first 20 cycles and similarly rapid decay in the subsequent 200 charge and discharge cycles. In stark contrast, the graphite material obtained in this example exhibits excellent cycling stability over 1400 charge and discharge cycles.

[0064] Example 6

[0065] Compared with Example 1, the graphite material in this example is changed to mesocarbon microbeads (MCMB), and other conditions remain unchanged. Figure 11-12 As shown, the graphite cathode material obtained in this example exhibits significantly better rate performance than unmodified MCMB. Meanwhile, MCMB exhibits poor cycling stability at 10C, experiencing a cliff-like capacity decay after 80 cycles. In stark contrast, the graphite material obtained in this example exhibits excellent cycling stability during charge and discharge testing, with a capacity retention rate of up to 92% after 1400 cycles.

[0066] Comparative Example 1

[0067] Compared with Example 1, this comparative example is waste graphite material without any treatment, and other conditions remain unchanged, and its interlayer spacing is about 0.336nm. Figure 5-6 As shown, the graphite cathode material in this comparative example exhibits poor rate performance. For example, when tested at a high rate of 20C, its capacity is almost zero. In addition, the cycling stability at 5C is poor, with rapid capacity decay in the early stages of the cycle and large capacity fluctuations during subsequent charge and discharge. This poor electrochemical performance is due to the small interlayer spacing and strong interlayer van der Waals forces of the graphite, which further enhance the anion intercalation resistance under high current conditions.

[0068] Comparative Example 2

[0069] Compared with Example 1, the ball milling time in this comparative example is 1 hour, and other conditions remain unchanged, and the interlayer spacing is about 0.339 nm. Figure 5-6 As shown, the graphite cathode material in this comparative example exhibits poor electrochemical performance. Compared with the comparative example, its rate performance is not improved and its cycle stability is even worse.

[0070] Comparative Example 3

[0071] Compared with Example 1, the mass ratio of the graphite material to the zirconia ball is 1:40, and other conditions remain unchanged. The interlayer spacing is about 0.348nm. Figure 13-14 As shown in Figure 2, the graphite cathode material in this comparative example exhibits good rate performance. However, the excessively high mass ratio of graphite material to zirconia balls increases defects in the graphite material, hindering the diffusion of anions and leading to a decreased capacity. Furthermore, the increase in defects also leads to poor cycling stability.

[0072] Comparative Example 4

[0073] Compared with Example 1, the ultrasonic treatment time in this comparative example was changed to 3 hours, and other conditions remained unchanged. Similar to Comparative Example 3, too long ultrasonic treatment time resulted in an increase in defects in the graphite material, thereby hindering the diffusion of anions. In addition, Figure 15 As shown in Figure 3, excessive defects have a negative impact on the cycling performance, such as the capacity retention rate is only 59% after 1000 cycles at a 5C rate.

[0074] Comparative Example 5

[0075] Compared with Example 1, the ultrasonic time of this comparative example was changed to 15 minutes, and other conditions remained unchanged. Figure 16-17As shown, the graphite positive electrode material obtained in this comparative example exhibits poor rate performance, with discharge capacities of 75, 61, 49, 45, 40, and 15 mAh / g at rates of 2, 4, 6, 8, 10, and 20 C, respectively; the cycle stability at 5 C is good, with a capacity retention rate of up to 76.6% after 1000 charge and discharge cycles.

[0076] Comparative Example 6

[0077] Compared with Example 1, this comparative example uses commercial flake graphite (KS-6) without any treatment, and other conditions remain unchanged. The KS-6 particles used in this comparative example are smaller in size and have a higher defect content, which affects the anion intercalation kinetics. Figure 18-19 As shown in the figure, the storage capacity of the KS-6 positive electrode is poor at a larger current; at the same time, the cycle stability is good at 5C, but due to more surface defects, the battery experiences rapid capacity decay in the early stage.

[0078] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A method for preparing high-rate dual-ion battery electrodes using waste graphite, the method comprising the following steps: Step 1. Add waste graphite negative electrode materials from lithium-ion batteries into deionized water, stir and disperse them evenly, and then ultrasonically treat them for 0.5-2 hours. Vacuum filter and dry the pretreated graphite negative electrode materials. The interlayer spacing of the waste graphite materials is 0.336nm±0.001nm. Step 2. Place the pretreated graphite material and zirconia balls in a ball mill at a mass ratio of 1:30 to 1:10 and ball mill for 1-12 hours to obtain graphite with weakened van der Waals forces; Step 3. Graphite that weakens van der Waals forces is mixed with a conductive agent and a binder in a dispersant at a mass ratio of 8:1:1, then evenly coated on the current collector, baked at 80°C for 12 hours, and cut into the desired shape to form a dual-ion battery positive electrode.

2. The method according to claim 1, characterized in that The mass ratio of the pretreated graphite material to the zirconia balls in step 2 is further preferably 1:25 to 1:15, more preferably 1:

20.

3. The method according to claim 1, characterized in that The ball milling time in step 2 is preferably 2-8 h, more preferably 3-6 h.

4. The method according to claim 1, wherein The diameter of the zirconia ball used in step 2 is 3 mm.

5. The method according to claim 1, characterized in that The graphite with weakened van der Waals force obtained in step 2 has a particle size of 5-10 μm, and the interlayer spacing of the graphite with weakened van der Waals force is 0.339-0.348 nm.

6. A high-rate dual-ion battery, comprising a high-rate dual-ion battery electrode prepared by the method according to any one of claims 1 to 5 as a positive electrode.

Images