Amino-modified lignin-based carbon / iodine integrated electrode material, and preparation method and application thereof

Abstract

The embodiment of the application relates to an amino-modified wood charcoal / iodine integrated electrode material and a preparation method and application thereof, the electrode material comprises an amino-modified wood charcoal substrate and iodine element, the amino-modified wood charcoal substrate loads the iodine element I2, and iodine of the iodine element exists in an amorphous form on the wood charcoal substrate, the wood charcoal substrate has a three-dimensional layered porous structure, the wood charcoal substrate is loaded on the surface and a microchannel, amino modified on the wood charcoal substrate is combined with carbon atoms in a chemical bond, and the electrode material can solve the problems of poor conductivity of an electrode material in a zinc-iodine battery positive electrode, low active iodine loading, and a multi-iodine ion shuttle effect.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of electrode materials, in particular to an amino-modified lignocellulosic carbon / iodine integrated electrode material and a preparation method and application thereof. BACKGROUND

[0002] Zinc-based aqueous batteries have high theoretical specific capacity (820 mAh·g -1 ), abundant zinc reserves, low electrode potential (relative to the standard hydrogen electrode-0.76 V), and good air stability, and have been considered as one of the most promising candidate batteries in the past few decades. Various aqueous zinc batteries, such as zinc-manganese oxide, zinc-vanadium oxide, zinc-prussian blue analog, zinc-air and zinc-halogen batteries, have been developed to improve energy and power density. Iodine (I2) has a low solubility in water (≈0.29 g L -1 ), making it suitable for aqueous batteries. Unlike traditional zinc batteries, which usually rely on the intercalation and deintercalation of Zn 2+ ions, aqueous zinc-iodine batteries store energy through the redox reaction of iodine at the positive electrode and the deposition / stripping of zinc at the negative electrode. Achieving the electrochemical redox of iodine in zinc-based aqueous batteries can provide considerable potential and a high theoretical capacity of 211 mAh·g -1 , thus attracting extensive attention. In addition, the multiple valence states of iodine (−1, 0, +1, +3, +5 and +7) make it theoretically have great potential for multi-electron conversion reactions. In recent years, static zinc-iodine batteries have made great progress in the development of high specific capacity and long-life positive electrode materials, mainly focusing on various carbon materials, single-atom materials, coordination materials, conductive polymers, etc., and attempts have also been made to suppress zinc negative electrode dendrite growth, inhibit byproduct generation and prevent polyiodide corrosion. In addition, new electrolytes and functionalized separators have made significant breakthroughs in zinc-iodine batteries. Although many progresses have been made, the development of zinc-iodine batteries is still in its infancy, and there are still key problems such as slow reaction kinetics, polyiodide ion shuttle effect, low energy density, and unstable zinc negative electrode, which greatly hinder the practical application of zinc-iodine batteries. SUMMARY

[0003] The present application is provided to solve the above-mentioned defects in the prior art. There is a need for an amino-modified lignocellulosic carbon / iodine integrated electrode material and a preparation method and application thereof to solve the problems of poor conductivity of the electrode material in the current zinc-iodine battery positive electrode, low active iodine loading, and polyiodide ion shuttle effect.

[0004] According to the embodiment of the present application, an amino-modified wood charcoal / iodine integrated electrode material is provided, which comprises an amino-modified wood charcoal substrate and iodine element, the amino-modified wood charcoal substrate is loaded with the iodine element I2, and the iodine in the iodine element exists in an amorphous form on the wood charcoal substrate, the wood charcoal substrate has a three-dimensional layered porous structure, the iodine element is loaded on the surface and microchannels of the wood charcoal substrate, and the modified amino group on the wood charcoal substrate is chemically bonded with carbon atoms.

[0005] In some embodiments, the diameter of the microchannels on the wood charcoal substrate is 5-50 μm.

[0006] According to the embodiment of the present application, a preparation method of the amino-modified wood charcoal / iodine integrated electrode material is also provided, which comprises: depositing an amino modifier on a wood charcoal substrate after carbonization by plasma in an atmosphere of ammonia to obtain an amino-modified wood charcoal substrate; and electrochemically depositing iodine element on the amino-modified wood charcoal substrate to obtain the amino-modified wood charcoal / iodine integrated electrode material.

[0007] In some embodiments, the power of the plasma deposition is 300-500 W, and the pressure is 10-30 Pa. Preferably, the power of the plasma deposition can be 350-450 W, and the pressure is 15-25 Pa. For example, the power of the plasma deposition is 400 W, 430 W, etc., and the pressure is 20 Pa, 25 Pa, etc.

[0008] In some embodiments, the time of the plasma deposition is 0.5-30 min. Preferably, the time of the plasma deposition is 1-15 min; further preferably, the time of the plasma deposition is 1-2 min; for example, 1 min, 1.2 min, 2 min, etc.

[0009] In some embodiments, the electrochemical deposition of the iodine element on the wood charcoal substrate comprises: mixing the wood charcoal substrate with an electrolyte solution of the iodine element, and obtaining the amino-modified wood charcoal / iodine integrated electrode material by electrochemical deposition.

[0010] In some embodiments, in the electrochemical deposition, the voltage is 1-4 V, and the power-on time is 10-50 min. Preferably, the voltage is 1-2 V, and the power-on time is 20-40 min. For example, the voltage is 1 V, 1.6 V, and 2 V, etc. The power-on time is 20 min, 30 min, 35 min, etc.

[0011] In some embodiments, the wood charcoal substrate after carbonization is obtained by the following method: wood is soaked in a hydrochloric acid solution to remove impurities; and the wood after removal of impurities is carbonized.

[0012] In some embodiments, after the wood is soaked in the hydrochloric acid solution, the soaked wood is washed and dried to remove impurities in the wood. The wood is then carbonized. The washing can be performed using water, ethanol, or a mixture of both.

[0013] In some embodiments, the process of carbonizing the wood can be performed in a tube furnace or other suitable closed device. The carbonization process includes: treating at 20-50℃ for 20-50min; heating at a first heating rate to 250-350℃, carbonizing at 250-350℃ for a first time period, heating at a second heating rate to 850-950℃, and carbonizing at 850-950℃ for a second time period, to obtain the carbonized wood charcoal.

[0014] In some embodiments, the first heating rate is 1-3℃ / min, and the corresponding first time period is 30min-2h.

[0015] In some embodiments, the second heating rate is 3-6℃ / min, and the corresponding second time period is 50min-3h.

[0016] According to the embodiments of the present application, the application further provides a use of the amino-modified wood charcoal / iodine integrated electrode material or the preparation method of the amino-modified wood charcoal / iodine integrated electrode material in a battery.

[0017] The amino-modified wood charcoal / iodine integrated electrode material and the preparation method and application thereof provided by the embodiments of the present application, the electrode material has a three-dimensional layered porous structure, and the iodine is loaded in the microchannels of the wood charcoal substrate. The amino group on the wood charcoal substrate is chemically bonded to the carbon atom. The electrode material has high conductivity and high capacity. As a zinc-iodine battery, the electrode material can increase the loading capacity of iodine, inhibit the shuttle effect of polyiodide, and improve the performance of the electrode. Therefore, the electrode material can solve the problems of poor conductivity of the electrode material, low active iodine loading capacity, and polyiodide shuttle effect in the positive electrode of the zinc-iodine battery. BRIEF DESCRIPTION OF DRAWINGS

[0018] In the drawings, which are not necessarily drawn to scale, like reference numerals can describe similar parts throughout the several views. Like reference numerals with an alphabetical suffix have different meanings or different instances of like parts. The drawings illustrate various embodiments by way of example, not by way of limitation. The same reference numerals in different drawings can represent the same or similar aspects of the application. Such embodiments of the inventive subject matter can be employed apart from one another as desired. Embodiments are illustrative of the application rather than limiting.

[0019] Figure 1 X-ray diffraction patterns of electrode materials of different embodiments are shown;

[0020] Figure 2(a) shows a first cross-sectional SEM image of carbonized wood (CW) according to Embodiment One of the present application;

[0021] Figure 2(b) shows a second cross-sectional SEM image of carbonized wood (CW) according to Embodiment One of the present application;

[0022] Figure 2(c) shows a first longitudinal cross-sectional SEM image of carbonized and ammoniated wood according to Embodiment One of the present application;

[0023] Figure 2(d) shows a second longitudinal cross-sectional SEM image of carbonized and ammoniated wood according to Embodiment One of the present application;

[0024] Figure 2(e) shows a first cross-sectional SEM image of N-CW-1 / I2 according to Embodiment One of the present application;

[0025] Figure 2(f) shows a second cross-sectional SEM image of N-CW-1 / I2 according to Embodiment One of the present application;

[0026] Figure 3(a) shows a first SEM energy dispersive spectroscopy image of an electrode material according to Embodiment One of the present application;

[0027] Figure 3(b) shows a second SEM energy dispersive spectroscopy image of an electrode material according to Embodiment One of the present application;

[0028] Figure 3(c) shows a third SEM energy dispersive spectroscopy image of an electrode material according to Embodiment One of the present application;

[0029] Figure 3(d) shows a fourth SEM energy dispersive spectroscopy image of an electrode material according to Embodiment One of the present application;

[0030] Figure 3(e) shows a fifth SEM energy dispersive spectroscopy image of an electrode material according to Embodiment One of the present application;

[0031] Figure 4 Infrared spectra of materials prepared according to different embodiments of the present application at different steps are shown;

[0032] Figure 5 Galvanostatic charge-discharge measurement results of electrode materials according to different embodiments of the present application are shown;

[0033] Figure 6 Test results of rate capability of electrode materials according to different embodiments of the present application are shown;

[0034] Figure 7(a) shows a first cyclic voltammogram of an electrode material according to different embodiments of the present application;

[0035] Figure 7(b) shows a second cyclic voltammogram of an electrode material according to different embodiments of the present application;

[0036] Figure 8 Figure 8 shows an electrochemical impedance spectrogram of an electrode material according to different embodiments of the present application. DETAILED DESCRIPTION

[0037] In order to better understand the technical solutions of the present application, the present application will be described in detail below in combination with the drawings and specific embodiments. The embodiments of the present application will be further described in detail below in combination with the drawings and specific embodiments, but are not intended to limit the present application.

[0038] The terms "first", "second", and similar terms used in the present application do not represent any order, number, or importance, but are only used to distinguish. The terms "include" or "contain" and similar terms mean that the elements before the terms cover the elements listed after the terms, and do not exclude the possibility of also covering other elements.

[0039] According to an embodiment of the present application, an amino-modified wood-based carbon / iodine integrated electrode material is provided, which comprises an amino-modified wood-based carbon substrate and iodine element, the wood-based carbon substrate is loaded with the iodine element I2, and the iodine in the iodine element exists in an amorphous form on the wood-based carbon substrate, the wood-based carbon substrate has a three-dimensional layered porous structure, the iodine element is loaded on the surface and microchannels of the wood-based carbon substrate, and the modified amino groups on the wood-based carbon substrate are chemically bonded with carbon atoms.

[0040] The three-dimensional layered porous structure of the wood-based carbon substrate has a high porosity, the arrangement of the pore structure is highly ordered, and the pore is in a low-curvature form, which provides abundant loading sites for the loading of the iodine element, realizes strong adsorption of iodine, and limits active iodine. The loading of the iodine element in the microchannels is conducive to improving the coating of the iodine element. The abundant microchannels can also adjust the performance of the zinc-iodine electrode material.

[0041] The wood-based carbon substrate with excellent electrical conductivity can provide sufficient electrons for the redox reaction between Zn 2+ and I − , and the assembled zinc-iodine battery has significant energy storage performance, which can solve the problem of poor electrical conductivity of the electrode material in the positive electrode of the current zinc-iodine battery.

[0042] The amino groups on the wood-based carbon substrate are chemically bonded with carbon atoms, so that the wood-based carbon surface can firmly bind the amino groups, which is conducive to exerting the limiting effect on active iodine.

[0043] The amino-modified lignocellulosic charcoal substrate, the Coulomb interaction between the positively charged amino groups on the lignocellulosic charcoal substrate and the negatively charged polyiodide anions, and the synergistic iodine storage mechanism of the physical confinement of the porous carbon, effectively improve the iodine species loading and inhibit the polyiodide shuttle.

[0044] The heteroatom-doped carbon material can improve the electrical conductivity, reduce the electrochemical polarization, improve the electrochemical reaction kinetics and the surface electron mobility of the lignocellulosic charcoal substrate, and also provide additional pseudo-capacitance. Therefore, the electrode material composed of the amino-modified lignocellulosic charcoal substrate and iodine has high conductivity, which can improve the application of the electrode material as a positive electrode material and improve the performance of the electrode material.

[0045] In some embodiments, the diameter of the microchannels on the lignocellulosic charcoal substrate is 5 μm-50 μm. The lignocellulosic charcoal substrate has abundant microchannels, and some small pores are also distributed between adjacent two large pores, providing abundant loading sites.

[0046] According to the embodiments of the present application, a preparation method of the amino-modified lignocellulosic charcoal / iodine integrated electrode material is also provided, and the preparation method comprises the following steps: using the carbonized lignocellulosic charcoal substrate, depositing an amino modifier on the lignocellulosic charcoal substrate by plasma in an atmosphere of ammonia to obtain an amino-modified lignocellulosic charcoal substrate; and electrochemically depositing iodine on the amino-modified lignocellulosic charcoal substrate to obtain the amino-modified lignocellulosic charcoal / iodine integrated electrode material.

[0047] In some embodiments, the power of the plasma deposition is 300-500 W, and the pressure is 10-30 Pa. Preferably, the deposition power of the plasma can be 350-450 W, and the pressure is 15-25 Pa. For example, the deposition power is 400 W, 430 W, etc., and the pressure is 20 Pa, 25 Pa, etc. In this way, the lignocellulosic charcoal is combined with the ammonia to form amino groups on the surface of the lignocellulosic charcoal.

[0048] In some embodiments, the deposition time of the plasma is 0.5 min-30 min. Preferably, the deposition time is 1-15 min. In a shorter time, the amino-modified lignocellulosic charcoal substrate can be obtained. The longer the deposition time, the more grafted amino groups, and the more electrochemically deposited iodine, the increased battery polarization, and the reduced capacity. Therefore, further preferably, the deposition time is 1-3 min; for example, 1 min, 1.2 min, 2 min, etc.

[0049] In some embodiments, the electrochemical deposition of iodine on the lignocellulosic charcoal substrate comprises mixing the lignocellulosic charcoal substrate with an electrolyte solution of iodine, and obtaining the amino-modified lignocellulosic charcoal / iodine integrated electrode material by electrochemical deposition.

[0050] In some embodiments, in the electrochemical deposition, the voltage is 1-4V, and the power-on time is 10-50min. Preferably, the voltage is 1-2V, and the power-on time is 20-40min. For example, 1V, 1.6V, 2V, etc. The power-on time is 20min, 30min, 35min, etc. So that the iodine element can be adsorbed and deposited on the lignocellulosic carbon substrate.

[0051] In some embodiments, the lignocellulosic carbon substrate after carbonization is obtained by the following method: the wood is soaked in a hydrochloric acid solution to remove impurities; and the wood after removing impurities is carbonized.

[0052] In some embodiments, after the wood is soaked in the hydrochloric acid solution, the soaked wood is washed and dried to remove impurities in the wood. Then the wood is carbonized. The washing can use water, ethanol or a mixture of both.

[0053] In some embodiments, the process of carbonizing the wood can be carried out in a tube furnace or other suitable closed equipment. The carbonization process includes: treating at 20-50℃ for 20-50min; heating at a first heating rate to 250-350℃, carbonizing at 250-350℃ for a first time period, heating at a second heating rate to 850-950℃, and then carbonizing at 850-950℃ for a second time period to obtain the carbonized lignocellulosic carbon. In some embodiments, the first heating rate is 1-3℃ / min, and the corresponding first time period is 30min-2h.

[0054] In some embodiments, the second heating rate is 3-6℃ / min, and the corresponding second time period is 50min-3h.

[0055] In this way, the carbonized lignocellulosic carbon with a three-dimensional layered porous structure can be obtained. The carbonized lignocellulosic carbon has low bending microchannels, i.e. a number of microchannels in the lignocellulosic carbon are arranged in one direction to form a relatively regular microchannel structure. The pore size of the microchannels ranges from 5 to 50 microns, including both small-pore microchannels and large-pore microchannels. The iodine element can be easily wrapped in the porous structure.

[0056] According to the embodiments of the present application, the application also provides a use of the amino-modified lignocellulosic carbon / iodine integrated electrode material or the preparation method of the amino-modified lignocellulosic carbon / iodine integrated electrode material in a battery. Further, the use of the amino-modified lignocellulosic carbon / iodine integrated electrode material in a zinc-iodine battery.

[0057] The amino-modified lignocellulosic carbon / iodine integrated electrode material can be used as a positive electrode material in a battery, which has good battery performance, including good cycle performance and rate performance, etc., so that the performance of the zinc-iodine battery is improved, which is conducive to the wide application of the zinc-iodine battery.

[0058] Embodiment one

[0059] (1) Preparation of CW electrode:

[0060] The natural poplar was cut into 2 x 2 x 0.2 cm along the growth direction 3 , immersed in 1 mol / L HCl solution for 1 h to remove impurities. After repeated washing with deionized water and ethanol, and natural drying for 12 h, the sample was placed in a N2-filled tube furnace, and kept static for 30 min at 20 °C, then carbonized at 300 °C, 2 °C / min -1 , and then heated to 900 °C, 5 °C / min -1 for 2 h to obtain carbonized wood carbon (CW);

[0061] (2) Preparation of N-CW-1 electrode:

[0062] The wood carbon carrier prepared in step (1) was placed in a plasma enhanced chemical vapor deposition system and ammonia was introduced. The plasma power was 400 W, the pressure was 20 Pa, and the treatment time was set to 1 min. The obtained product was labeled as N-CW-1;

[0063] (3) Preparation of N-CW-1 / I2 electrode:

[0064] Electrochemical deposition of iodine-loaded N-CW (N-CW / I2): The N-CW-1 electrode prepared in step (2) was charged in 1 mol / L ZnI2 electrolyte at 1.6 V (relative to Zn metal anode) for 30 min to obtain I2 electrode. After being placed in a refrigerator for 12 h, it was freeze-dried at -80 °C, 0 Pa for 24 h. The obtained product was labeled as N-CW-1 / I2.

[0065] The zinc-iodine battery assembled with the iodine cathode of N-CW-1 prepared in Example 1 can provide 6.82 mg cm -2 , with high iodine mass loading, still has a high capacity of 0.026 mAh cm -2 at 2 mA cm -2 , and can be stably operated for 1000 times, realizing high capacity and high energy density.

[0066] Example Two

[0067] Preparation of N-CW-2 / I2 electrode:

[0068] (1) The same as step (1) of Example One;

[0069] (2) The wood charcoal carrier prepared in step (1) was put into a plasma enhanced chemical vapor deposition system and ammonia gas was introduced, the plasma power was 400 W, the pressure was 20 Pa, and the treatment time was set to 2 min, and the obtained product was marked as N-CW-2, respectively;

[0070] (3) The same as step (3) of Example 1, marked as N-CW-2 / I2.

[0071] Example Three

[0072] Preparation of N-CW-15 / I2 electrode:

[0073] (1) The same as step (1) of Example 1;

[0074] (2) The wood charcoal carrier prepared in step (1) was put into a plasma enhanced chemical vapor deposition system and ammonia gas was introduced, the plasma power was 400 W, the pressure was 20 Pa, and the treatment time was set to 15 min, and the obtained product was marked as N-CW-15, respectively;

[0075] (3) The same as step (3) of Example 1, marked as N-CW-15 / I2.

[0076] Example Four

[0077] Preparation of N-CW-20 / I2 electrode:

[0078] (1) The same as step (1) of Example 1;

[0079] (2) The wood charcoal carrier prepared in step (1) was put into a plasma enhanced chemical vapor deposition system and ammonia gas was introduced, the plasma power was 400 W, the pressure was 20 Pa, and the treatment time was set to 20 min, and the obtained product was marked as N-CW-20, respectively;

[0080] (3) The same as step (3) of Example 1, marked as N-CW-20 / I2.

[0081] Comparative Example One

[0082] Preparation of N-CW-0 / I2 electrode:

[0083] (1) The same as step (1) of Example 1, marked as N-CW-0;

[0084] (2) The same as step (3) of Example 1, marked as N-CW-0 / I2.

[0085] Figure 1X-ray diffraction patterns of carbonized wood (CW), carbonized ammoniated wood (N-CW-1) prepared in Example 1 and wood loaded with iodine under different ammonia treatment times. Two broad diffraction peaks were observed at 25.8° and 43.1°, which belong to the (002) and (100) crystal planes of graphite carbon, respectively. In addition, the XRD spectra of N-CW-1 / I2 (A4 curve) prepared in Example 1, N-CW-2 / I2 (A5 curve) prepared in Example 2 and N-CW-15 / I2 (A3 curve) prepared in Example 3 did not show obvious I2-related diffraction peaks, indicating that iodine was well combined with the carbon host and existed in amorphous form.

[0086] Figures 2(a) and 2(b) are SEM images of the cross-section of carbonized wood (CW) prepared in Example 1 (step 1), which clearly shows that CW has a three-dimensional porous structure composed of many arranged open micro-channels, which is beneficial for the rapid penetration of electrolyte and the loading of iodine when used as a positive electrode carrier for zinc-iodine batteries. Figures 2(c) and 2(d) are SEM images of the longitudinal section of carbonized ammoniated wood 1 min (N-CW-1) prepared in Example 1 (step 2), which shows that after treating the carbonized wood with ammonia plasma for 1 min, the porous morphology did not change significantly, and a hierarchical pore structure was formed on the pipe wall. The internal structure is relatively stable, and the small pores are still uniformly distributed without obvious collapse and destruction. These pores connect the inherent channels of carbon to form a three-dimensional network transmission structure. The increase in the specific surface area of the ammoniated carbonized wood leads to an increase in the loading and dispersion of active components. Figures 2(e) and 2(f) are SEM images of the cross-section of carbonized ammoniated wood 1 min loaded with iodine (N-CW-1 / I2) prepared in Example 1 (step 3); after electrochemically depositing iodine on the ammoniated carbonized wood, N-CW-1 / I2 retains the three-dimensional anisotropic porous structure of CW, with a rich pore size range of 5 to 50 microns on the top surface and a large number of aligned open micro-channels along the vertical direction, which indicates that the coating of iodine species and the introduction of N heteroatoms have no significant effect on the porous structure of the carbon substrate, as most of the iodine is encapsulated in the porous structure rather than accumulating on the surface of the sample.

[0087] In addition to the preservation of the porous structure, the in-situ generation of iodine particles on N-CW-1 and their uniform distribution were further confirmed by corresponding SEM energy dispersive X-ray (EDX) elemental mapping analysis, as shown in FIG. 3(a), FIG. 3(b) corresponds to N element, FIG. 3(c) corresponds to Zn element, FIG. 3(d) corresponds to C element, and FIG. 3(e) corresponds to iodine I element. In addition to the uniform N-doping in the NCW matrix, the signal of I element can also be detected throughout N-CW-1 / I2, which confirms the uniform coating of I species on the inner and outer microchannels of N-CW-1 / I2. Most importantly, a macroscopically structurally intact self-supporting wood carbon electrode can be obtained, which can be directly used as the positive electrode of the zinc-iodine battery, avoiding the use of adhesives for the lengthy slurry-based electrode assembly process.

[0088] Figure 4 are the infrared spectra of carbonized (CW) prepared in Example One (Step 1), carbonized ammoniated 1 min (N-CW-1) prepared in Example One (Step 2), and carbonized ammoniated 1 min iodine-loaded wood (N-CW-1 / I2) prepared in Example One (Step 3), Figure 4 The horizontal axis in FIG. 4 is the wavelength, and the vertical axis is the transmittance ratio. All three materials have relatively obvious diffraction peaks. Compared with CW, N-CW-1 and N-CW-1 / I2 have N-H stretching vibration absorption peaks at 3300-3400 cm -1 and N-H bending vibration absorption peaks (slightly lower in intensity than the N-H stretching vibration absorption peak) at 1600-1650 cm -1 , indicating that the ammonium cations are successfully modified on the surface of the wood carbon electrode after ammonia plasma treatment.

[0089] Performance test

[0090] Figure 5 are the cycle performances of N-CW-0 / I2 prepared in Comparative Example One, N-CW-1 / I2 prepared in Example One, N-CW-2 / I2 prepared in Example Two, N-CW-15 / I2 prepared in Example Three, and N-CW-20 / I2 prepared in Example Four, which were tested by constant current charge and discharge measurement at a current density of 2 mA·cm -2 Figure 5 The horizontal axis in FIG. 5 is the cycle number, and the vertical axis is the discharge capacity. After 1000 cycles, the capacities of N-CW-0 / I2, N-CW-1 / I2, N-CW-2 / I2, N-CW-15 / I2, and N-CW-20 / I2 electrodes at a current density of 2 mA·cm -2 -2 ​​The N-CW-1 / I2 cathode prepared in Example 1 has good capacity retention because the shuttle effect of iodide is inhibited.

[0091] Figure 6 Figure 7(a) is the CV curve of N-CW-2 / I2 prepared in Example 2 (D2), the CV curve of N-CW-15 / I2 prepared in Example 3 (D1) and the CV curve of N-CW-20 / I2 prepared in Example 4 (D3), and Figure 7(b) is the CV curve of N-CW-0 / I2 prepared in Comparative Example 1 (E2) and the CV curve of N-CW-1 / I2 prepared in Example 1 (E1), in which the abscissa is voltage and the ordinate is current. The N-CW-1 / I2 battery prepared in Example 1 is diffusion-controlled during the charge-discharge cycle, showing a typical battery type. CV tests were conducted on N-CW-0 / I2 and N-CW-1 / I2, and a pair of representative redox peaks were observed on the N-CW-0 / I2 and N-CW-1 / I2 electrodes, which is consistent with the I2 / I Figure 6 The longitudinal order of the image points is indicated by arrows at different positions in the middle, Figure 6 The abscissa is cycle number and the ordinate is discharge capacity. When the current density is stably at 1, 2, 3, 4 and 5 mA·cm -2 , the specific capacity of the battery of the N-CW-0 / I2 cathode is only 0.433, 0.065, 0.026, 0.024, 0.020 mAh·cm -2 . In contrast, the capacity decay of the N-CW-1 / I2, N-CW-2 / I2, N-CW-15 / I2 and N-CW-20 / I2 electrodes is better than that of the N-CW-0 / I2 electrode, and the N-CW-1 / I2 electrode has the smallest capacity decay and the best performance.

[0092] The abscissa is cycle number and the ordinate is discharge capacity. When the current density is stably at 1, 2, 3, 4 and 5 mA·cm -2 , the specific capacity of the battery of the N-CW-0 / I2 cathode is only 0.433, 0.065, 0.026, 0.024, 0.020 mAh·cm -2 . In contrast, the capacity decay of the N-CW-1 / I2, N-CW-2 / I2, N-CW-15 / I2 and N-CW-20 / I2 electrodes is better than that of the N-CW-0 / I2 electrode, and the N-CW-1 / I2 electrode has the smallest capacity decay and the best performance.

[0093] Figure 7(a) is the CV curve of N-CW-2 / I2 prepared in Example 2 (D2), the CV curve of N-CW-15 / I2 prepared in Example 3 (D1) and the CV curve of N-CW-20 / I2 prepared in Example 4 (D3), and Figure 7(b) is the CV curve of N-CW-0 / I2 prepared in Comparative Example 1 (E2) and the CV curve of N-CW-1 / I2 prepared in Example 1 (E1), in which the abscissa is voltage and the ordinate is current. The N-CW-1 / I2 battery prepared in Example 1 is diffusion-controlled during the charge-discharge cycle, showing a typical battery type. CV tests were conducted on N-CW-0 / I2 and N-CW-1 / I2, and a pair of representative redox peaks were observed on the N-CW-0 / I2 and N-CW-1 / I2 electrodes, which is consistent with the I2 / I -The voltage difference of the battery using N-CW-1 / I2 cathode was significantly reduced (0.163 mV) compared to N-CW-0 / I2 electrode (0.173 mV), which indicated that the electrochemical polarization was reduced and the reaction kinetics was accelerated. This favorable property can be attributed to the nitrogen doping, which is beneficial to faster reaction kinetics. In addition, the high peak current of the battery using N-CW-1 / I2 cathode was much larger than that of N-CW-0 / I2, which indicated that the capacity of the battery using N-CW-1 / I2 cathode was larger than that of the battery using N-CW-0 / I2.

[0094] Figure 8 Electrochemical impedance spectrograms of N-CW-0 / I2 prepared in Comparative Example 1, N-CW-1 / I2 prepared in Example 1, N-CW-2 / I2 prepared in Example 2, N-CW-15 / I2 prepared in Example 3 and N-CW-20 / I2 prepared in Example 4, wherein, at the position corresponding to the arrow, the curves from bottom to top in the direction of the arrow are N-CW-1 / I2, N-CW-20 / I2, N-CW-15 / I2, N-CW-2 / I2 and N-CW-0 / I2, respectively, Figure 8 The horizontal and vertical coordinates are the real and imaginary parts of the electrochemical impedance, respectively. The N-CW-1 / I2 electrode prepared in Example 1 has the smallest charge transfer resistance compared to N-CW-0 / I2, N-CW-2 / I2, N-CW-15 / I2 and N-CW-20 / I2, which indicates that the appropriate ammonia plasma strategy improves the surface electron mobility and electrochemical reaction kinetics of the carbonized wood carbon substrate.

[0095] Furthermore, although exemplary embodiments have been described herein, the scope of the claims includes any and all embodiments having equivalent elements, modifications, omissions, combinations (e.g., of

[0096] The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) can be used in combination with each other. Other embodiments can be used, which will be apparent to those of ordinary skill in the art upon reviewing the above description. Additionally, the various features described above can be grouped together or divided into separate features for the purpose of simplifying the present disclosure. This should not be interpreted as a requirement to practice a claim in any particular embodiment. Rather, the subject matter of the application can be practiced without all of the features of a particular embodiment. Accordingly, the following claims are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment, and the scope of the application is afforded the full breadth of each claim. The description of the embodiments is intended to be illustrative, and not to limit the scope of the application. Many variations to those embodiments can be readily envisioned by those skilled in the art following the teaching provided herein, and the scope of the present application is defined by the appended claims and their equivalents.

[0097] The above embodiments are only exemplary embodiments of the present application, not intended to limit the present application, and the protection scope of the present application is defined by the claims. Those skilled in the art can make various modifications or equivalent replacements to the present application within the spirit and protection scope of the present application, and such modifications or equivalent replacements should also be considered to fall within the protection scope of the present application.

Claims

1. An electrode material of amino-modified lignin charcoal / iodine integration, characterized in that, The electrode material comprises an amino-modified wood-based carbon substrate and iodine element, the amino-modified wood-based carbon substrate is loaded with the iodine element I2, and the iodine in the iodine element exists in an amorphous form on the wood-based carbon substrate, the wood-based carbon substrate has a three-dimensional layered porous structure, the iodine element is loaded on the surface and microchannels of the wood-based carbon substrate, and the modified amino groups on the wood-based carbon substrate are chemically bonded to carbon atoms.

2. The electrode material of claim 1, wherein, The diameter of the microchannels on the wood-based carbon substrate is 5-50 μm.

3. A method of producing the electrode material as claimed in claim 1 or 2, characterized in that: The preparation method comprises: amino-modified wood-based carbon substrate is obtained by plasma deposition of an amino modifier on the wood-based carbon substrate after carbonization under an atmosphere of ammonia; and iodine element is electrochemically deposited on the amino-modified wood-based carbon substrate to obtain the amino-modified wood-based carbon / iodine integrated electrode material.

4. The method of claim 3, wherein The power for plasma deposition is 300-500 W, and the pressure is 10-30 Pa.

5. The production method according to claim 3, wherein The time for plasma deposition is 0.5-30 min.

6. The preparation method according to claim 3, characterized in that, The electrochemical deposition of the iodine element on the wood-based carbon substrate comprises: mixing the wood-based carbon substrate with an electrolyte solution of the iodine element, and obtaining the amino-modified wood-based carbon / iodine integrated electrode material by electrochemical deposition.

7. The production method according to claim 6, characterized by, In the electrochemical deposition, the voltage is 1-4 V, and the power-on time is 10-50 min.

8. The preparation method according to claim 3, characterized in that, The wood-based carbon substrate after carbonization is obtained by the following method: wood is soaked in a hydrochloric acid solution to remove impurities; and the wood after removal of impurities is carbonized.

9. The production method according to claim 8, characterized by, The carbonization process comprises: treatment at 20-50 ℃ for 20-50 min; heating at a first heating rate to 250-350 ℃, carbonization at 250-350 ℃ for a first time period, heating at a second heating rate to 850-950 ℃, and carbonization at 850-950 ℃ for a second time period to obtain the wood-based carbon after carbonization.

10. Use of the amino-modified wood-based carbon / iodine integrated electrode material of any one of claims 1-2 or the preparation method of the amino-modified wood-based carbon / iodine integrated electrode material of any one of claims 3-9 in a battery.

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