Semiconductor electricity storage material, electricity storage body, and stacked electricity storage body

Abstract

Provided are a semiconductor electricity storage material, an electricity storage body, and a laminated electricity storage body, each of which is composed of a biological material and has both semiconductor characteristics and electricity storage characteristics. The present invention relates to a fiber sheet having a fiber mainly composed of chitin or chitosan, formed in a sheet shape, and having a density of 2 g / cm3 or less. The fibers are preferably crystalline fibers / amorphous fibers, and are preferably composed of bundles or granular aggregates of chitin nanofibers or chitosan nanofibers having a width of 3-400 nm. In addition, the semiconductor is preferably an n-type bulk material semiconductor, and preferably has an N-type negative resistance.

Description

Technical Field

[0001] This invention relates to semiconductor energy storage materials, energy storage elements, and laminated energy storage elements. Background Technology

[0002] Semiconductors are electronic components that utilize the property that their conductivity changes significantly due to the introduction of impurities or the influence of heat, light, magnetic fields, voltage, current, radiation, etc. They are indispensable components in low-voltage electronic devices. Semiconductors are widely used in various diodes, transistors, FETs (Field Effect Transistors), SITs (Static Induction Transistors), RAMs (Random-Access Memory), ROMs (Read-Only Memory), CCDs (Charge Coupled Devices), etc. In recent years, the rapid advancement of high-performance IT products such as mobile phones and ultra-small storage devices, as well as batteries for electric vehicles, has led to a growing demand for smaller, larger-capacity semiconductors with high performance in storage and other functions. There is a particular demand for products suitable for a smart grid (next-generation transmission grid) society that aligns with green innovation (decarbonization) aimed at preventing global warming. For example, the capacitor market, used in automobiles, IT equipment, and energy-saving inverters, is expanding steadily at an average annual growth rate of approximately 3.7%, reaching a market size of 1 trillion yen.

[0003] Previously, inorganic and organic materials were used in the aforementioned semiconductor materials. These are all man-made materials, and the vast majority of their raw materials are harmful to the Earth's environment and the survival of all living things, including humans. Therefore, it is best to avoid using toxic elements such as arsenic, lead, cadmium, beryllium, and mercury, as well as environmentally polluting substances such as lithium, chromium, and sulfur, in semiconductor materials. In other words, semiconductors require healthy and harmless inexpensive materials.

[0004] Semiconductors can be broadly categorized into high-voltage power circuits (strong current) and electronic / electrical equipment circuits (weak current) applications. For weak current applications, Si or compound semiconductors are primarily used as the main semiconductor material in electronic / electrical equipment circuits. For example, the inventors of this invention have developed a metal / semiconductor type transistor made from an amorphous Ni-Nb-Zr-H alloy (see, for example, Non-Patent Documents 1-5 and Patent Document 1). Furthermore, organic semiconductors are being reused in television and smartphone products as materials for organic electroluminescent (EL) cells or organic solar cells, which are key components.

[0005] Among organic semiconductor components, there are those that contribute to increased carbon dioxide emissions and those that form microplastics, which can cause marine pollution. From the perspective of protecting flora and fauna and safeguarding the Earth's environment, the manufacture of such components is being increasingly avoided globally. Therefore, developing a semiconductor that minimizes environmental impact during production and disposal, is lightweight, and utilizes wood / plant fiber (cellulose) derived from highly resilient plants, aligns with the current trend towards environmental protection.

[0006] Although semiconductors using carbon-neutral biomaterials have not been used before, by focusing on utilizing renewable plant fibers that are gentle on the Earth's environment, the inventors of this invention have discovered n-type semiconductors obtained from kenaf, a non-wood annual herb, or conifers, which are represented by wood, and have developed DC / AC components, insulator / metal conduction switching components, rectifier biomaterials, and room-temperature transistors made from fibrous materials derived from wood / plant fiber (pulp) molecules (for example, see Non-Patent Document 6).

[0007] On the other hand, capacitors, originally electronic components used to store charge (electrical energy) or discharge it through electrostatic capacitance, play an indispensable role in mobile electronic devices such as computers and mobile phones, serving functions such as power supply stability, backup circuitry, coupling elements, and noise filtering. In recent years, the rapid advancements in high-performance IT products such as mobile phones and ultra-small storage devices, as well as batteries for electric vehicles, have led to a growing demand for smaller, larger-capacity semiconductors with high-performance storage capabilities.

[0008] For example, conventional capacitors are characterized by using amorphous titanium dioxide, amorphous alumina, amorphous polymers, etc., as materials, and having uneven surfaces with electrical insulation (e.g., see Non-Patent Documents 7-15). However, these are all man-made products, and from the perspective of protecting the Earth's environment, it is undesirable to use capacitors that use harmful compounds such as Li or Pb. In this regard, by focusing on utilizing renewable plant fibers, the inventors of this invention discovered that TEMPO oxidized cellulose nanofibers (CNF), which uses biomaterials from coniferous trees, exhibit strong energy storage effects, and developed an energy storage material and supercapacitor made of cellulose molecules obtained from wood / plant fibers (pulp) that can store electricity under both DC and AC conditions (e.g., see Non-Patent Documents 16, 17 or Patent Document 2).

[0009] Existing technical documents Non-patent literature Non-patent document 1: M. Fukuhara, A. Kawashima, S. Yamaura, and A. Inoue, "Coulomb oscillation of a proton in a Ni-Nb-Zr-H glassy alloy with multiple junctions", Appl. Phys., 2007, 90, 203111 Non-Patent Literature 2: M. Fukuhara and H. Kawarada, “Room-temperature amorphous alloy field-effect transistor exhibiting particle and wave electronic transport”, J. Appl. Phys., 2015, 117, 084302 Non-patent literature 3: M. Fukuhara, H. Yoshida, K. Koyama, A. Inoue, Y. Miura, “Electronic transport behaviors of Ni-Ngb-Zr-H glassy alloys”, J. Appl. Phys., 2010, 107, 033703 Non-patent document 4: Mikio Fukuhara, Hajime Yoshida and Hiroshi Kawarada, "Effect of hydrogen and cluster morphology on the electronic behavior of Ni-Nb-Zr-H glassy alloys with subnanometer-sized icosahedral Zr5Ni5Nb5clusters", Euro. Phys. J., D, 2013, 67:40 Non-Patent Literature 5: M. Fukuhara and H. Kawarada, “Room-temperature amorphous alloy field-effect transistor exhibiting particle and wave electronic transport”, J. Appl. Phys., 2015, 117, 084302 Non-patent document 6: M. Fukuhara, T. Yokotsuka, T. Hashida, F. Ogawa, T.Sakamoto, M. Takeda, S. Arai, "A novel n-type semiconducting biomaterial", Scientific Reports, 2022, 12, 21899 Non-patent document 7: M. Fukuhara, H. Yoshida, M. Sato, K. Sugawara, T. Takeuchi, I. Seki, and T. Sueyoshi, "Superior electric storage in de-alloyedand anodic oxidized Ti-Ni-Si glassy alloy ribbons", Phys. Stat. Sol. RRL, 2013, 7(7), p.477-480 Non-patent document 8: M. Fukuhara and K. Sugawara, “Electric charging / discharging characteristics of super capacitor, using de-alloying and anodicoxidized Ti-Ni-Si amorphous alloy ribbons”, Nanoscale. Res. Lett., 2014, 9, p.253 Non-patent document 9: M. Fukuhara and K. Sugawara, "Anodic oxidization of Ti-Ni-Si amorphous alloy ribbons and their capacitive and resistive properties", Thin Solid Films, 2015, 595, 1-4 Non-patent literature 10: M. Fukuhara, T. Kuroda and F. Hasegawa, “Amorphoustitanium-oxide supercapacitors”, Sci. Rep., 2016, 6, 35870 Non-patent literature 11: M. Fukuhara, T. Kuroda, F. Hasegawa and T. Sueyoshi, “Superior electric storage on an amorphous perfluorinated polymer surface,” Sci. Rep., 2016, 6, 22012 Non-patent literature 12: M. Fukuhara, T. Kuroda, F. Hasegawa, T. Hashida, E. Kwonand K. Konno, “Amorphous aluminum-oxide supercapacitors,” EuroPhys. Lett., 2018, 123, 58004 Non-Patent Literature 13: M. Fukuhara, T. Kuroda, F. Hasegawa, Y. Shirai, T. Suwa, T. Hashida, and M. Nishijima, “Amorphous titanium-oxide supercapacitors with high capacitance”, EuroPhys. Lett., 2019, 128, 58001 Non-patent literature 14: M. Fukuhara, T. Kuroda, F. Hasegawa, T. Hashida, M. Takeda, K. Konnno, and N. Fujima, “AlO6clusters' electric storage effect inamorphous alumina supercapacitors”, Sci. Rep., 2021, 11, 1699 Non-Patent Literature 15: M. Fukuhara, T. Yokotsuka, T. Hashida, K. Yamaguchi, and N. Fujima, “Amorphous alumina supercapacitors with voltage-charging performance”, EuroPhys. Lett., 2023, 141, 36003 Non-patent literature 16: M. Fukuhara, T. Kuroda, F. Hasegawa, T. Hashida, and M. Takeda, N. Fujima, M. Morita, and T. Nakatani, “Amorphous cellulose nanofiber supercapacitors”, Sci. Rep., 2021, 11, 6436 Non-patent document 17: M. Fukuhara, T. Yokotsuka, T. Hashida, T. Miwa, N.Fujima, M. Morita, and T. Nakatani, and F. Nonomura “Amorphous cellulosenanofiber supercapacitors with voltage-charging performance”, Sci. Rep., 2022, 12, 5619 Patent documents Patent Document 1: International Publication No. WO2011 / 037003 Patent Document 2: International Publication No. WO2021 / 166813 Summary of the Invention

[0010] (a) Technical problems to be solved However, the semiconductor using the biomaterial described in Non-Patent Document 6 showed almost no energy storage effect. Furthermore, the energy storage materials made of biomaterials described in Non-Patent Documents 16 and 17 and Patent Document 2 did not show significant semiconductor characteristics. Therefore, it is clear that, to date, there is no biomaterial that simultaneously possesses semiconductor and energy storage properties.

[0011] The present invention addresses the aforementioned technical problems and aims to provide a semiconductor energy storage material, an energy storage body, and a laminated energy storage body that are composed of biological materials and simultaneously possess semiconductor and energy storage properties.

[0012] (II) Technical Solution The inventors of this invention have discovered that when crystalline CNF / amorphous CNF with CNF bundles of 3-400 nm generated, for example, by physical fiber splitting, is used, semiconductor properties are exhibited due to the quantum size effect of the electron-proton double layer formed in the thin film, while electrical storage properties are also observed due to the C2-bonded acetamide or amino groups. That is, this phenomenon is found to be the same as that of previous amorphous Ni-Nb-Zr-H alloys, caused by the formation of proton tunneling (solid protons) in crystalline / amorphous fibers and aggregates composed of these fibers.

[0013] Furthermore, the inventors of this invention noted that, in the case of molecules with the formula (C8H) 13 NO5) n The chitin represented is composed of the molecular formula (C6H). 11 NO4) n In chitosan, a nitrogen-containing polysaccharide polymer, the dipoles formed by hydroxyl (OH) groups and acetamide or amino (NO) groups are ordered in the same direction. The inventors of this invention discovered that this is because it structurally functions similarly to a one-dimensional hydrogen bond chain of water, acting as a chain-like protonic soliton, capable of forming an electric double layer with electrons. Thus, the inventors of this invention completed this invention.

[0014] Specifically, the semiconductor energy storage material of the present invention is characterized in that it has fibers with chitin or chitosan as the main component, and is formed in a sheet-like shape with a density of 2 g / cm³. 3 the following.

[0015] The semiconductor energy storage material of this invention comprises fibers mainly composed of chitin or chitosan, which are natural amino polysaccharides, and is made of biomaterials. The semiconductor energy storage material of this invention uses chitin obtained from the exoskeleton of crustaceans such as crabs or shrimp, or chitosan obtained by deacetylation of chitin through boiling in concentrated alkali, as the main component. By fiberizing these components, in the case of chitin as the biomaterial, numerous dipoles formed by hydroxyl and acetamide groups bonded to the inner surface can be formed; in the case of chitosan as the biomaterial, numerous dipoles formed by hydroxyl and amino groups bonded to the inner surface can be formed. Furthermore, similar to cellulose polymerized from β-glucose, the molecules readily form sheets through hydrogen bonding, thus enabling the instantaneous formation of an electric double layer, which serves as the basis for proton movement. Therefore, the semiconductor energy storage material of this invention achieves a high-dielectric-domain structure through the formation of an electric double layer, exhibiting both semiconductor and energy storage properties simultaneously.

[0016] The semiconductor energy storage material of the present invention is represented by an equivalent circuit consisting of two electrical circuits connected in parallel, which are composed of an electric double layer. Therefore, the semiconductor energy storage material of the present invention can be formed into transistors exhibiting various properties. Furthermore, regarding the semiconductor energy storage material of the present invention, the positively charged dipoles formed by acetamide groups or amino (NO) groups facilitate the physical adsorption of negatively charged electrons.

[0017] Regarding the semiconductor energy storage material involved in this invention, the resistivity of the two double layers in the equivalent circuit is preferably 10. -1 ~10 12 Ωm, more preferably 10 3 Ωm or more and 10 7 Below Ωm. Furthermore, the electrical capacitance of each double layer is preferably 10. -8 ~10 -5 F.

[0018] The semiconductor energy storage material of the present invention is in sheet form, preferably with a thickness of 100 μm or less, and particularly preferably in thin film form with a thickness of 20 μm or less. In this case, a lightweight effect is particularly expected.

[0019] In the semiconductor energy storage materials of this invention, "fibers with chitin or chitosan as the main component" refers to fibers made from insects such as crabs or shrimps, silkworms, cicadas, beetles, or antibacterial fungi such as filamentous fungi, and containing more than 50% by mass of chitin or chitosan. More specifically, it refers to fibers made from the main components of the exoskeleton (i.e., skin) of arthropods or crustaceans, the skin of mollusks, and the cell membranes of fungi such as molds / mushrooms, and containing more than 50% by mass of chitin or chitosan.

[0020] In the semiconductor energy storage material of the present invention, the fiber is preferably a crystalline fiber / amorphous fiber. In this case, the fiber may have nanocrystals. Furthermore, the fiber may be an amorphous fiber with atomic vacancies. Moreover, as long as an electric double layer can be formed on the inner surface, the material of the crystalline fiber / amorphous fiber can be any material, such as chitin fiber or chitosan fiber. As chitin fiber and chitosan fiber, chitin nanofibers and chitosan nanofibers are preferably used respectively. Chitin nanofibers and chitosan nanofibers can enhance the electron-withdrawing ability brought about by the quantum size effect of the negative sixth power law, increase the work function, and further increase the dielectric domain.

[0021] [Chitin fiber, chitosan fiber] Chitin fibers and chitosan fibers can be of any kind, for example, mucopolysaccharide polymers derived from microbial products such as arthropods or mollusks (e.g., squid), insects (e.g., silkworms, beetles, cicadas, etc.), and fungi (e.g., molds, mushrooms). Furthermore, fibers derived from animals are preferred, and chitosan fibers from crabs, shrimps, and mantis shrimps are particularly preferred.

[0022] Regarding chitin fibers and chitosan fibers, the average fiber diameter can be any size. The average fiber length and average fiber diameter of chitin fibers and chitosan fibers can be adjusted through oxidation and fiber-opening treatments. As for nanofibers, although the diameter varies depending on the degree of fiber opening, conventionally purified nanofibers are microfibers with a diameter of approximately 3-400 nm. The average fiber diameter and average fiber length of nanofibers can be obtained by averaging the fiber diameter and fiber length obtained from observations of each fiber using atomic force microscopy (AFM) or transmission electron microscopy (TEM).

[0023] Regarding chitin nanofibers and chitosan nanofibers, an average aspect ratio of 50 or less is preferred, and aggregated into granules is particularly preferred. Furthermore, granular refers to the shape after being finely pulverized through fiber opening. Additionally, the average aspect ratio can be calculated using the following mathematical formula.

[0024] Average aspect ratio = average fiber length / average fiber diameter [Opening treatment of chitin fibers and chitosan fibers] The method for opening chitin fibers and chitosan fibers can be any method, but preferably a method using a high-speed rotary mill, colloid mill, high-pressure mill, roller mill, ultrasonic mill, or similar device to apply a strong shear force to the dispersion of chitin fibers or chitosan fibers. For efficient opening, a wet high-pressure or ultra-high-pressure homogenizer capable of applying a pressure of 50 MPa or more and a strong shear force to the dispersion of chitin fibers or chitosan fibers is preferred. The pressure during opening is preferably 100 MPa or more, and more preferably 140 MPa or more. The number of processing cycles using the opening device can be once, but is preferably two or more.

[0025] In the dispersion process used to form the dispersion, it is preferable to disperse chitin fibers or chitosan fibers in a solvent. The solvent can be any solvent, such as water, organic solvents (e.g., ethanol, acetic acid, lactic acid, succinic acid), or mixtures of these solvents, as long as the chitin fibers or chitosan fibers can be dispersed. Since cellulose fibers are hydrophilic, water is particularly preferred as the solvent.

[0026] Furthermore, chitin fibers or chitosan fibers can be pretreated as needed before using a high-pressure homogenizer for fiber opening / dispersion. Pretreatment can be performed, for example, using mixing, stirring, emulsifying, and dispersing devices such as high-speed shear mixers.

[0027] In the semiconductor energy storage material of this invention, chitin fibers and chitosan fibers can be fibers in an aqueous dispersion state obtained after fiber opening treatment, or fibers that have undergone post-treatment as needed. Post-treatment methods include, for example, drying (freeze-drying, spray drying, plate drying, drum drying, belt drying, drying by thinly spreading on a glass plate, fluidized bed drying, microwave drying, hot air fan-type vacuum drying, etc.), redispersion in water (using any dispersion device), pulverization (using equipment such as a cutter mill, hammer mill, pin mill, air jet mill, bead mill, etc.), and high-speed rotary filtration such as a film gyratory mixer (FILMIX).

[0028] In the semiconductor energy storage material of the present invention, the fiber is preferably composed of bundles or granular aggregates of chitin nanofibers or chitosan nanofibers with a width of 3-400 nm. In this case, the formation efficiency of the electric double layer can be improved.

[0029] Regarding the semiconductor energy storage material involved in this invention, the specific surface area of ​​the fiber is preferably 750~900 m². 2 / g, preferably 800~900m 2 / g.

[0030] The semiconductor energy storage material involved in this invention is preferably an n-type bulk semiconductor. In this case, it can be represented by an equivalent circuit consisting of two parallel circuits having a low-resistance band with a low-current band and a high-resistance band with a high-current band.

[0031] The semiconductor energy storage material of the present invention is preferably composed of a bulk semiconductor material having N-type negative resistance. It is particularly preferred to exhibit N-type negative resistance under high voltage loads of 1 kV / cm or higher. In this case, it can be used, for example, as a DC / AC conversion element or a switching element between metals and insulators, and also has a rectifying function.

[0032] The energy storage body of the present invention is characterized by having: the semiconductor energy storage material of the present invention; and a pair of metal electrodes respectively disposed on both sides of the semiconductor energy storage material in a manner that clamps the semiconductor energy storage material.

[0033] The energy storage device of the present invention is equivalent to a lumped-parameter capacitor having two visible capacitors between each metal electrode. Furthermore, in the energy storage device of the present invention, each metal electrode is made of, for example, Al, Cu, gold, polythiophene, etc., and can be manufactured using a microelectromechanical system (M(N)EMS) by sputtering, casting, or scraping methods. Moreover, the energy storage device of the present invention is preferably capable of operating at temperatures from -269°C to 300°C.

[0034] Furthermore, the energy storage device involved in this invention can be constructed from a parallel integrated assembly, in which a plurality of the semiconductor energy storage materials are arranged between a pair of electrodes made of conductors. In this case, 600 mJ / m² can be obtained. 2 The above-mentioned energy storage capacity and withstand voltage of 1MV / m or higher. Each electrode is, for example, a metal or a conductive polymer.

[0035] The feature of the stacked energy storage body of the present invention is that it is composed of a stack of multiple energy storage bodies of the present invention.

[0036] The stacked energy storage device of the present invention can be stacked in parallel using various M(N)EMS methods. When used as a semiconductor, the stacked energy storage device of the present invention can be represented as a semiconductor formed by combining multiple parallel equivalent circuits with lumped electrical parameters; when used as an energy storage device, it can be represented as an energy storage device formed by combining multiple parallel equivalent circuits with constant electrical distribution.

[0037] The semiconductor energy storage materials, energy storage elements, and laminated energy storage elements involved in this invention can be used as semiconductors, for example, as AC transmitters or control devices in microelectronic circuits, overcurrent protection switches, etc. Furthermore, they can be used in various amplifiers, microwave transmitters, pump sources for parametric amplifiers, police radar, access control systems, intrusion detection systems, shunt regulators, protection circuits, and other electronic / electrical infrastructure equipment.

[0038] The semiconductor energy storage materials, energy storage elements, and laminated energy storage elements involved in this invention can be used as energy storage elements, such as AC capacitors for microelectronic circuits and energy storage elements on the back of solar panels. Furthermore, they can be used in various backup power modules, coupling elements, noise filters, high-sensitivity accelerometers, high-output transformer circuit breaker devices, emergency power supply devices for automobiles or ships, and other electronic / electrical infrastructure equipment. In addition, they are expected to be used as DC energy storage materials for sunlight from outer space in the future. Examples of energy storage elements include antistatic sheets, lightning protection paper, shielding paper for electronic devices, films, positively charged dust-absorbing paper, and coating films.

[0039] (III) Beneficial Effects According to the present invention, a semiconductor energy storage material, an energy storage body, and a laminated energy storage body made of biological materials and simultaneously possessing semiconductor and energy storage properties can be provided. Attached Figure Description

[0040] Figure 1 A perspective view showing the molecular structure of (a) chitin and (b) chitosan, which constitute the fibers of the semiconductor energy storage material according to an embodiment of the present invention.

[0041] Figure 2 An electrical circuit diagram illustrating the equivalent circuit of the semiconductor energy storage material according to an embodiment of the present invention is provided.

[0042] Figure 3 A graph illustrating the frequency analysis results of the current in the N-type negative resistance region of the semiconductor energy storage material according to an embodiment of the present invention.

[0043] Figure 4 An atomic force microscope (AFM) image showing the surface of a semiconductor energy storage material according to an embodiment of the present invention.

[0044] Figure 5 A graph and a Nyquist plot showing the impedance of the semiconductor energy storage material according to an embodiment of the present invention are provided.

[0045] Figure 6 A graph illustrating the IV characteristics of the semiconductor energy storage material according to an embodiment of the present invention.

[0046] Figure 7 A graph illustrating the discharge curve of the semiconductor energy storage material according to an embodiment of the present invention.

[0047] Figure 8 A graph illustrating the RV characteristics of the semiconductor energy storage material according to an embodiment of the present invention.

[0048] Figure 9 The following are side views (a) to (c), perspective view (d), and side view (e), and perspective view (f) and plan view (g) of the equivalent circuit of the manufactured stacked energy storage device, illustrating the MEMS-based manufacturing method of the stacked energy storage device according to the embodiment of the present invention. Detailed Implementation

[0049] The embodiments of the present invention will be described below with reference to the accompanying drawings and examples.

[0050] The semiconductor energy storage material in the embodiments of the present invention is composed of... Figure 1 Chitin or shown in (a) Figure 1 The crystalline / amorphous fibers shown in (b) are composed of chitosan as the main component and are formed as sheets with numerous uneven surfaces.

[0051] The semiconductor energy storage material of this invention has a high-dielectric-domain structure with a double electric layer, and can simultaneously exhibit semiconductor and energy storage characteristics. Therefore, as... Figure 2 As shown, the semiconductor energy storage material of the present invention is equivalent to an electrical lumped parameter circuit formed by two electrical circuits connected in parallel, consisting of a double electric layer. Therefore, the semiconductor energy storage material of the present invention can be formed into transistors exhibiting various performance characteristics.

[0052] The following describes the fabrication of a semiconductor energy storage material according to an embodiment of the present invention, and examines its electrical characteristics, etc. Furthermore, the following embodiments are provided merely for illustrating the present invention and for reference to its specific form, and do not limit or restrict the scope of the invention disclosed in this application.

[0053] Example Example 1 The semiconductor energy storage material of the present invention in Sample 1 is manufactured in the following manner.

[0054] The shells of red snow crabs, which have a low calcium content, were used as raw materials. After soaking the shells in 2 mol / L (2N) hydrochloric acid for 5 hours, they were washed, dried, and pulverized. Further decalcification was then carried out while stirring in hydrochloric acid for 48 hours. Then, the process of adding the shells to 1 mol / L (1N) sodium hydroxide and heating at 100°C for 12 hours was repeated four times to remove protein. The shells were then dried to obtain crude chitin. Next, the crude chitin was soaked in a 0.5% potassium permanganate solution for 1 hour and washed with water. Then, it was added to a 1% oxalic acid solution and stirred at 60°C for 40 minutes to obtain pure white α-chitin. Finally, it was subjected to fiber opening treatment by a roll forming method.

[0055] After using α-chitin with fiber opening treatment, a 2% chitin aqueous solution slurry was prepared by scraping, and then dried by evaporating the water using a hot plate at 100°C to prepare α-chitin sheets of sample 1.

[0056] The surface of the α-chitin sheet of the prepared sample 1 was observed using atomic force microscopy (AFM), confirming that it was formed by bundles of fibrous chitin nanofibers with a width of 3-400 nm. Furthermore, it was confirmed that these chitin nanofibers were amorphous.

[0057] A pair of metal electrodes were placed on both sides of the α-chitinous sheet of sample 1, clamping the sample 1, and various measurements were performed. First, an AC signal was applied between the electrodes using the AC impedance method to measure the absolute value of the impedance of sample 1 and the phase difference between voltage and current. Furthermore, a Schottky circuit was constructed using carbon with a work function of 5.0 and Al with a work function of 4.2 in each electrode. The measurement results were plotted on a complex plane, and the shape formed by arranging two arcs of different sizes was plotted.

[0058] Among them, Figure 2 In the equivalent circuit shown, by changing the resistivity of resistors R1 and R2 and the capacitance of capacitors C1 and C2, the resistivity and capacitance that best fit the measurement result when the Nyquist plot is obtained by the least squares method are: R1 = 35 kΩm, R2 = 21 kΩm, C1 = 3 × 10⁻⁶. -8 F, C2 = 7 × 10 -7 F. Based on these results, it was confirmed that sample 1 is equivalent to... Figure 2 The circuit shown has two visible capacitors (double layer) and its electrical lumped parameters, forming a semiconductor with two bands: a low-resistance band for low current and a high-resistance band for high current.

[0059] Next, a voltage was applied between the electrodes of sample 1, and the IV characteristics at room temperature were measured. The results confirmed that sample 1 exhibited semiconductor characteristics displaying N-type negative resistance between -70 V and -60 V. Furthermore, it was confirmed that it exhibited a rectifying effect, showing no current flow in the negative charge region but a sudden increase in current in the positive charge region.

[0060] The current between each electrode was measured between -70V and -60V, and frequency analysis was performed. The results are presented below. Figure 3 .like Figure 3 As shown, a peak vibrational frequency was confirmed at 1.5 kHz. Based on this result, it is believed that sample 1 underwent DC / AC conversion. Furthermore, this result is similar to the Gunn effect confirmed in GaAs (gallium arsenide) semiconductors.

[0061] Next, the discharge curve of sample 1 after charging at 450V for 3 seconds was obtained. The energy storage capacity was calculated by the area enclosed by the discharge curve, the voltage axis, and the time axis, and the result was 502.5 mJ / m². 2 .

[0062] In addition, the density of sample 1 was measured, and the result was 1.4 g / cm³. 3 It was confirmed to be 2g / cm³. 3The following is a description of the low density. Furthermore, it was confirmed that sample 1 could operate up to 500V in a furnace used for low to medium temperatures, within a range of -269℃ to 200℃. Additionally, the specific surface area of ​​sample 1 was determined by the BET adsorption method, and the result was 800 m². 2 / g.

[0063] Example 2 The semiconductor energy storage material of the present invention in sample 2 is manufactured in the following manner.

[0064] After homogenizing the α-chitin of sample 1 before fiber splitting, it was added to a 48% sodium hydroxide solution and reacted at 120°C for 30 minutes to obtain chitosan. A 2% chitosan aqueous solution slurry was prepared from this chitosan and dropped onto a Si substrate of a spin coater. The Si substrate was rotated at 500 rpm to form a thin film. Then, the film was dried by evaporating the water using a hot plate at 100°C to prepare chitosan sheets.

[0065] The surface of the chitosan sheet of prepared sample 2 was observed using atomic force microscopy (AFM). The AFM image of sample 2 is shown below. Figure 4 .like Figure 4 As shown, it was confirmed that the chitosan sheet of sample 2 was formed of a material composed of bundles or granular aggregates of fibrous chitosan nanofibers with a diameter of 200-400 nm. Furthermore, it was confirmed that the chitosan nanofibers were amorphous fibers.

[0066] A pair of metal electrodes were placed on both sides of the chitosan sheet of sample 2, clamping it in place, for various measurements. First, the absolute value of the impedance of sample 2 and the phase difference between voltage and current were measured using AC impedance spectroscopy, in the same manner as in Example 1. Figure 5 The diagram shows a graph created by plotting the measurement results on a complex plane. (Example) Figure 5 As shown, the measurement results confirmed the shape formed by arranging two arcs of different sizes, which was then drawn into a diagram.

[0067] Then, in the same manner as in Example 1, Figure 2 In the equivalent circuit shown, by changing the resistivity of resistors R1 and R2 and the capacitance of capacitors C1 and C2, the best fit can be found using the least squares method. Figure 5 The Nyquist plot of the measurement results shown in the figure is... Figure 5 The solid lines represent the values. The resistivity and capacitance at this point are R1 = 17 kΩm, R2 = 5 kΩm, and C1 = 3 × 10⁻⁶. -7 F, C2 = 5 × 10 -6 F. For example Figure 5 As shown, the measurement results are almost identical to the Nyquist plot, therefore they are the same as those for sample 1. Sample 2 is equivalent to... Figure 2The circuit with two visible capacitors (double layer) shown in the figure confirms that a semiconductor with two bands is formed, namely a low-resistance band for low current and a high-resistance band for high current.

[0068] Next, a voltage was applied between the electrodes of sample 2, and the IV characteristics at room temperature were measured. The results are shown below. Figure 6 .like Figure 6 As shown, it was confirmed that sample 2 exhibited semiconductor characteristics with N-type negative resistance in the range of -180V to -170V and -70V to -60V (the range enclosed by circles A and B in the figure). Furthermore, it was confirmed that it exhibited a rectifying effect, showing no current flow in the negative charge region but a sudden increase in current in the positive charge region (the range enclosed by circle C in the figure).

[0069] Next, in Figure 7 The figure shows the discharge curve when sample 2 is charged at 450V for 3 seconds and then discharged. According to... Figure 7 The energy storage capacity was calculated by using the area enclosed by the discharge curve, the voltage axis, and the discharge time axis shown in the figure. The result was 1004.4 mJ / m². 2 Additionally, it is believed that the energy storage capacity increases under high voltage loads above 400V.

[0070] In addition, the density of sample 2 was measured, and the result was 1.0 g / cm³. 3 It was confirmed to be 2g / cm³. 3 The following is a description of the low density. Furthermore, it was confirmed that sample 2 could operate up to 500V within a temperature range of -269℃ to 200℃ in a furnace used for low to medium temperatures. Additionally, the specific surface area of ​​sample 2 was determined by the BET adsorption method, and the result was 800 m². 2 / g.

[0071] Example 3 The semiconductor energy storage material of the present invention in sample 3 is manufactured in the following manner.

[0072] Cuttlefish bone nucleus was used as the raw material. After soaking in 2 mol / L (2N) hydrochloric acid for 5 hours, the raw material was washed with water, dried, and pulverized. Further decalcification was carried out while stirring in hydrochloric acid for 48 hours. Then, the process of adding it to 1 mol / L (1N) sodium hydroxide and heating at 100°C for 12 hours was repeated four times to remove protein. Further drying yielded crude chitin. Next, after soaking the crude chitin in a 0.5% potassium permanganate solution for 1 hour and washing with water, it was added to a 1% oxalic acid solution and stirred at 60°C for 40 minutes to obtain β-chitin. Although the β-chitin had a balanced arrangement of sugar chains and loose hydrogen bonds, making it easy to handle, the yield of cuttlefish bone nucleus as the raw material was lower than that of crab used as the raw material in Sample 1.

[0073] After the β-chitin was split by cutting and grinding, a 2% chitin aqueous solution slurry was prepared by scraping. The water was then evaporated and dried using a hot plate at 50°C to prepare β-chitin sheets of sample 1.

[0074] The surface of the β-chitin sheet of the prepared sample 3 was observed using atomic force microscopy (AFM), confirming that it was formed by bundles of fibrous chitin nanofibers with a width of 3-400 nm. Furthermore, it was confirmed that these chitin nanofibers consisted of fibers containing 5% nanocrystals within an amorphous fiber structure.

[0075] A pair of metal electrodes were placed on both sides of the β-chitin sheet of sample 3, clamping it in place, and various measurements were performed. First, the absolute value of the impedance of sample 3 and the phase difference between voltage and current were measured by AC impedance method in the same manner as in Example 1, and the Nyquist plot was obtained. The resistivity and capacitance at this time were: R1 = 14 kΩm, R2 = 7 kΩm, C1 = 5 × 10⁻⁶. -8 F, C2 = 4 × 10 -7 F. Based on this result, it is confirmed that, similar to sample 1, sample 3 is also equivalent to... Figure 2 The circuit shown has two visible capacitors (double layer) and its electrical lumped parameters, forming a semiconductor with two bands: a low-resistance band for low current and a high-resistance band for high current.

[0076] Next, the discharge curve of sample 3 after charging at 450V for 3 seconds was obtained. The energy storage capacity was calculated from the area enclosed by the discharge curve, the voltage axis, and the time axis, and the result was 240.1 mJ / m². 2 .

[0077] Next, a voltage was applied between the electrodes of sample 3, and the RV characteristic at room temperature was measured. The results are shown below. Figure 8 .like Figure 8 As shown, it was confirmed that as the voltage increased, the resistance value of sample 3 rapidly increased by about 3-4 bits from 0V to about 1.5V, and then decreased by about 3 bits. This result is believed to be due to the switching effect between the metal and insulator. It is believed that this is due to the unique characteristics of n-type bulk semiconductors, which have both low-resistance bands for low current and high-resistance bands for high current, rather than the effect of pn-bonded semiconductors.

[0078] In addition, the density of sample 3 was measured, and the result was 1.5 g / cm³. 3 It was confirmed to be 2g / cm³. 3The following low density was observed. Furthermore, it was confirmed that sample 3 could operate up to 500V within a temperature range of -269℃ to 200℃ in a furnace used for low to medium temperatures. Additionally, the specific surface area of ​​sample 3 was determined by the BET adsorption method, yielding a result of 800 m². 2 / g.

[0079] Table 1 summarizes the sample types, fiber opening methods, structures (differences between crystalline and amorphous), densities, resistivity, electrical capacity, and energy storage capacity of the semiconductor energy storage materials of samples 1 to 3.

[0080] [Table 1] As shown in Table 1, the semiconductor energy storage materials identified in samples 1-3 are as follows: Figure 2 The circuit shown is composed of an electrical lumped parameter circuit, which consists of AC resistors R1 (14~35kΩm), R2 (5~21kΩm), and electrical capacitance C1 (10). -8 F~10 -6 F and C2 are 10 -7 F~10 -5 The two electric double layers of F constitute the basis for the n-type semiconductor phenomenon that does not exhibit pn-junction bulk behavior. Furthermore, its strength was confirmed to be 2 g / cm³. 3 The following are examples of low density. Furthermore, samples 1-3 were confirmed to possess energy storage characteristics, capable of operating up to 500V within a temperature range of -269℃ to 200℃. Additionally, the specific surface area of ​​samples 1-3 was confirmed to be 800 m². 2 / g. Therefore, it is considered that the semiconductor energy storage materials composed of biological materials in samples 1-3 are the most suitable materials in the field of weak current.

[0081] In addition, when sample 2 was irradiated with 3 mA / m 2 When subjected to a powerful electron beam, it was confirmed to have an electrical withstand capability up to 200 keV. This is more than twice the electrical withstand capability of 80 keV for carbon nanotubes.

[0082] Figure 9 The stacked energy storage device of the present invention is shown in the embodiment.

[0083] like Figure 9 As shown, the stacked energy storage device of the embodiment of the present invention uses the sheet-like semiconductor energy storage material of sample 2 and is manufactured by MEMS method in the following manner. First, as Figure 9 As shown in (a), a Cu layer (500 nm thick) is formed on the surface of a glass substrate (40 × 40 × 0.5 mm) by sputtering. Then, as... Figure 9 As shown in (b), a sheet-like sample 2 is placed on the Cu layer, and further, as shown in... Figure 9As shown in (c), an Al layer (500 nm thick) was formed on sample 2 by sputtering. This enables the fabrication of... Figure 9 The structure shown in (d) is a sheet-like semiconductor energy storage material having a carbon layer and an Al layer as metal electrodes on both sides. This structure corresponds to the structure used in the various measurements of Examples 1-3, which has metal electrodes on both sides of Sample 1-Sample 3.

[0084] Next, the glass substrate is removed to form a basic body. By stacking multiple of these basic bodies, it is possible to manufacture... Figure 9 The laminated energy storage device of the present invention is shown in (e) of the diagram. The manufactured laminated energy storage device is formed such that the Al layer of the uppermost base body and the carbon layer of the lowermost base body serve as terminals, and as shown in the diagram... Figure 9 As shown in (f) and (g) in the figure, it is a structure formed by connecting multiple semiconductor energy storage materials in parallel.

[0085] The semiconductor energy storage material of this invention, due to its lightweight nature, can be widely used in a wide range of applications, from low-voltage fields such as mobile phones, drones, and wall-mounted televisions to high-voltage fields such as automobiles, ships, and aircraft. Furthermore, it can be used in power modules for applications such as surge arresters, welding, and over-discharge protection; sensors for access control systems, intrusion detection systems, and pedestrian safety systems; control devices for microelectronics; remote vibration detectors; transmitters, and other electronic / electrical infrastructure. Examples of energy storage materials include antistatic sheets, surge protection paper, electronic device shielding paper, films, positively charged dust-absorbing paper, and coating films.

Claims

1. A semiconductor power storage material, characterized by, It has fibers with chitin or chitosan as a main component, and is formed into a sheet shape with a density of 2 g / cm 3 The following.

2. The semiconductor power storage material according to claim 1, wherein The fiber is a crystalline fiber / amorphous fiber.

3. The semiconductor power storage material according to claim 1, wherein The fiber is composed of a bundle or a granular aggregate of chitin nanofibers or the chitosan nanofibers having a width of 3 to 400 nm.

4. The power storage device according to claim 1, wherein The specific surface area of the fibers is 750-900 m 2 / g.

5. The power storage device according to claim 1, wherein It is a bulk material semiconductor of n type.

6. The semiconductor power storage material according to claim 1, wherein It has N type negative resistance.

7. A power storage body, characterized by It has: The semiconductor power storage material according to any one of claims 1 to 6; and A pair of metal electrodes disposed on both surfaces of the semiconductor power storage material in a manner of sandwiching the semiconductor power storage material.

8. A laminated power storage device, characterized by comprising: It is composed of a laminate in which a plurality of the power storage bodies according to claim 7 are laminated.

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