Light assisted plasmonic enhancement of photoelectric performance secondary battery

Abstract

The application discloses a kind of secondary batteries based on light-assisted plasma enhanced photoelectric performance.It uses plasma complex lithium-containing semiconductor material or lithium-free semiconductor material with plasma effect as positive electrode.The plasma complex lithium-containing semiconductor material is obtained by doping lithium-containing semiconductor material with nano material with plasma effect, and the nano material with plasma effect and semiconductor material have completely overlapping or partially overlapping light response range.Positive electrode captures incident light and generates plasma on the surface of positive electrode to increase the total number of external use electrons and improve the specific capacity of the battery.The secondary battery of the application can effectively reduce the battery interface resistance and increase the electronic conductivity of electrode material under the effect of plasma enhancement, thereby improving the battery capacity.

Description

Technical Field

[0001] This invention belongs to the field of secondary battery technology and relates to a secondary battery with enhanced photoelectric performance based on light-assisted plasma. Background Technology

[0002] Rechargeable lithium-ion batteries are widely used in various portable electronic products. However, with the rapid growth of lithium-ion batteries in industrial applications, the demand for their energy density and power output is increasing. Existing electrochemical energy storage technologies, considering factors such as cost, process, and performance, are still unable to meet practical needs.

[0003] Lithium cobalt oxide (LiCoO2) is a high-performance cathode material with a theoretical specific capacity of up to 273.8 mAh / g. However, when the voltage exceeds 4.25 V, the structure of LiCoO2 changes, and its performance rapidly declines. Due to the instability of its crystal structure, LiCoO2 materials can only utilize 50% of their actual capacity. Modification of LiCoO2 through doping or coating can improve the battery's capacity and stability. Erchao Meng et al. demonstrated that, through the multiple synergistic effects of nano-silver, the corresponding order-disorder transition signal in LiCoO2 / Ag was almost unobservable in LiCoO2. This implies that after long-term cycling, the structure of LiCoO2 may be destroyed under high voltage, leading to increased electrochemical polarization, reduced capacity, and voltage decay. The results show that Ag additives can delay the irreversible phase transition in LiCoO2. This allows the LiCoO2 / Ag cathode to exhibit excellent specific capacity and rate performance achieved by nano-Ag by enhancing Li ion diffusion, electron transport, and improving structural stability. The initial discharge specific capacity of LiCoO2 was improved by introducing 100 mA·g between 3.0 and 4.5 V. -1 Nano-Ag at (~0.7C) can increase its capacity by 12%, and after 100 cycles, the discharge specific capacity is improved by 52%. Furthermore, when the current density is increased to 2000 mA·g... -1 At that time, the specific capacity retention of LiCoO2 / Ag reached 62%, which is higher than that of 52% LiCoO2 (Erchao Meng, Bihui Jin, You Hu, et al. Superior lithiumion storage performance of LiCoO2 cathode at 4.5V enabled by the multiple synergistic effect of nano-silver[J]. Journal of the Electrochemical Society). Summary of the Invention

[0004] The purpose of this invention is to provide a secondary battery with photo-assisted plasma-enhanced photoelectric performance. This battery can effectively reduce the interfacial resistance and increase the conductivity of the electrode material under the effect of plasma enhancement, thereby improving the battery capacity.

[0005] The light-assisted plasma-enhanced photoelectric secondary battery of this invention uses a plasma-composite lithium-containing semiconductor material or a lithium-free semiconductor material with its own plasma effect as the positive electrode. The plasma-composite lithium-containing semiconductor material is obtained by doping a lithium-containing semiconductor material with a nanomaterial having a plasma effect. The nanomaterial with the plasma effect and the lithium-containing semiconductor material have completely or partially overlapping light response ranges. The positive electrode shell of the secondary battery is provided with an optical window or the substrate of the positive electrode film is transparent. When the frequency of the incident photons passing through the optical window or the substrate of the positive electrode film is the same as the plasma oscillation frequency in the positive electrode, the absorption of the incident light is enhanced, and a plasma resonance is formed on the local surface in the absorption spectrum region. This generates plasmon-induced resonance energy transfer at the positive electrode, producing electron-hole pairs. The electrons are transferred to the negative electrode to form a photocurrent. Through the superposition of photogenerated electrons and the secondary battery itself, the total number of electrons released for external use increases, thereby improving the specific capacity of the secondary battery.

[0006] In this invention, when a plasma-reinforced lithium-containing semiconductor material is used as the positive electrode of a secondary battery, the plasmon energy is higher than the band gap of the lithium-containing semiconductor material, enhancing light absorption in the positive electrode, achieving broadband light absorption, promoting the transport of electrons and ions within the positive electrode, and charge transfer at the electrode / electrolyte interface, thereby improving the efficiency of the positive electrode. In this invention, the plasma-effect-enabled lithium-free semiconductor material is a conventionally used plasma-effect-enabled lithium-free material in the art, such as vanadium pentoxide (V₂O₅), molybdenum oxide (MoO₃), and tungsten oxide (WO₃).

[0007] In a specific embodiment of the present invention, the semiconductor material with plasma effect used is MoO3.

[0008] In this invention, the lithium-containing semiconductor material is a lithium-containing material with semiconductor properties commonly used in the art, such as lithium iron phosphate (LiFePO4), lithium cobalt oxide (LiCoO2), and lithium manganese oxide (LiMn2O4).

[0009] In this invention, the plasma-effect nanomaterials are conventionally used plasma-effect nanomaterials in the art, such as metals or their corresponding metal oxides, specifically gold (Au), silver (Ag), ruthenium (Ru), copper (Cu), cobalt (Co), nickel (Ni), titanium (Ti), or their corresponding metal oxides.

[0010] Specifically, in this invention, the plasma composite lithium-containing semiconductor material is LiCoO2 doped with Ag nanoparticles, LiCoO2 doped with Au nanoparticles, or LiCoO2 doped with Ru nanoparticles.

[0011] In a specific embodiment of the present invention, the plasma composite lithium-containing semiconductor material used is LiCoO2 doped with Ag nanoparticles.

[0012] Preferably, in the plasma-conjugated lithium semiconductor material, the doping amount of the oxide or salt of the nanomaterial with plasma effect is 0.5 wt.% to 5 wt.%.

[0013] In this invention, the positive electrode of the light-assisted plasma-enhanced photoelectric performance secondary battery is in the form of a thin film or a sheet. When incident light irradiates the positive electrode, plasma is excited on the surface of the plasma-composite lithium-containing semiconductor material or the lithium-free semiconductor material with its own plasma effect, thereby increasing the specific capacity of the secondary battery by increasing the total number of externally used electrons.

[0014] In this invention, the light-transmitting substrate is a conventional substrate used in the art for preparing positive and negative electrodes of batteries, such as the mesh current collector used in bulk solid-state batteries and the FTO conductive glass used in solid-state thin-film batteries. The mesh current collector has a mesh structure, allowing incident light to pass through the optical window of the positive electrode shell and irradiate the surface of the plasma-reinforced semiconductor material or the lithium-free semiconductor material with its own plasma effect. The FTO conductive glass is light-transmitting, allowing incident light to directly pass through the FTO conductive glass and irradiate the surface of the plasma-reinforced semiconductor material or the lithium-free semiconductor material with its own plasma effect.

[0015] In this invention, the positive electrode of the light-assisted plasma-enhanced photoelectric secondary battery is prepared using methods conventionally used in the art. For example, a sheet-like positive electrode is made by uniformly coating a plasma-composite lithium-containing semiconductor material or a lithium-free semiconductor material with its own plasma effect, a binder, and a conductive agent mixed in proportion on the surface of a mesh-like positive electrode current collector. Alternatively, a thin film-like positive electrode is deposited by magnetron sputtering of a plasma-composite semiconductor material or a lithium-free semiconductor material with its own plasma effect onto the surface of an FTO conductive glass.

[0016] Specifically, the method for preparing the positive electrode of the light-assisted plasma-enhanced photoelectric secondary battery includes the following steps:

[0017] A positive electrode is obtained by modifying a transparent substrate surface with a plasma-reinforced lithium-containing semiconductor material or a lithium-free semiconductor material with its own plasma effect; wherein the plasma-reinforced lithium-containing semiconductor material is prepared through the following steps:

[0018] A lithium-containing semiconductor material is uniformly mixed with a precursor of a metal nanomaterial with a plasma effect, and then calcined to obtain a plasma-composite lithium-containing semiconductor material. The precursor of the metal nanomaterial with a plasma effect is an oxide or salt of a metal with a plasma effect.

[0019] Alternatively, lithium-containing semiconductor materials can be directly mixed with metal oxide nanomaterials that have a plasma effect to obtain plasma-composite lithium-containing semiconductor materials.

[0020] In this invention, the type of secondary battery with enhanced photoelectric performance based on light-assisted plasma is a conventional type of secondary battery in the art, such as a solid-state thin-film battery or a bulk solid-state battery.

[0021] The solid-state battery of the present invention comprises, from top to bottom: a positive electrode shell, a positive electrode made of plasma-composite lithium-containing semiconductor material or lithium-free semiconductor material having plasma effect, a solid electrolyte, a negative electrode, and a negative electrode shell, wherein the positive electrode shell is provided with an optical window.

[0022] The solid-state thin-film battery of the present invention comprises, from bottom to top: an FTO conductive glass substrate, a positive electrode film of plasma-composite lithium-containing semiconductor material or lithium-free semiconductor material with its own plasma effect, a solid electrolyte film, a negative electrode film, and a negative electrode current collector film.

[0023] In this invention, all components of the above-mentioned light-assisted plasma-enhanced photoelectric performance secondary battery, except for the positive electrode, are made of conventional materials in the art, and the secondary battery is assembled using conventional methods.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] The secondary battery of the present invention uses plasma composite lithium-containing semiconductor material or lithium-free semiconductor material with plasma effect as positive electrode. Under light-assisted excitation, the positive electrode can capture more incident photons. The captured incident photons act on the positive electrode material. At the same time, the oscillating electric field brought by the external voltage causes the conduction electrons to oscillate together. The free oscillating electrons on the surface of the positive electrode interact with the captured photons to generate electron compression waves that propagate along the metal surface, i.e., surface plasma.

[0026] When the frequency of the incident photon matches the oscillation frequency of the plasma within the positive electrode, resonance occurs, resulting in strong absorption of the incident light. This leads to localized surface plasmon resonance (SPR), which is associated with a large dipole moment. This dipole moment can couple to the semiconductor. SPR occurring in the absorption spectral region can generate plasmon-induced resonance energy transfer at the positive electrode, producing a large number of electron-hole pairs. Electrons then transfer to the negative electrode, forming a photocurrent. Therefore, the combined effect of photogenerated electrons and the battery itself increases the total number of electrons released for external use, significantly improving the battery's specific capacity. Furthermore, when the plasmon energy exceeds the semiconductor band gap, it increases light absorption in the positive electrode, achieving efficient broadband light absorption. This promotes rapid electron and ion transport within the positive electrode and charge transfer at the electrode / electrolyte interface, improving the positive electrode's efficiency and further enhancing the battery's capacity. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the solid-state battery structure of the present invention.

[0028] Figure 2 This is a schematic diagram of the solid-state thin-film battery structure of the present invention.

[0029] Figure 3 This is the photoresponse diagram of LiCoO2.

[0030] Figure 4 This is a band gap width diagram of LiCoO2.

[0031] Figure 5 The graph shows the electrochemical performance of the battery in Example 6 after several cycles under both light and dark conditions.

[0032] Figure 6 The graph shows the electrochemical performance of the battery in Example 11 under both light and dark conditions.

[0033] Figure 7 This is a rate performance test chart of the battery under light and no light conditions in Example 11. Detailed Implementation

[0034] To better understand the technical content of the present invention, specific embodiments are described below in conjunction with the accompanying drawings.

[0035] Various aspects of the invention are described in this disclosure with reference to the accompanying drawings, in which numerous illustrative embodiments are shown. The embodiments of this disclosure are not necessarily intended to encompass all aspects of the invention. It should be understood that the various concepts and embodiments described above, as well as those described in more detail below, can be implemented in any of many ways, because the concepts and embodiments disclosed herein are not limited to any particular implementation.

[0036] The present invention provides a light-assisted plasma-enhanced photoelectric secondary battery, which uses a plasma-composite lithium-containing semiconductor material or a lithium-free semiconductor material with its own plasma effect as the positive electrode. The plasma-composite lithium-containing semiconductor material is obtained by doping a lithium-containing semiconductor material with a nanomaterial having a plasma effect. The nanomaterial with the plasma effect and the semiconductor material have completely or partially overlapping light response ranges. The positive electrode shell of the secondary battery is provided with an optical window or the substrate of the positive electrode film is transparent. When the frequency of the incident photons passing through the optical window or the substrate of the positive electrode film is the same as the plasma oscillation frequency in the positive electrode, the absorption of the incident light is enhanced, and a plasma resonance is formed on the local surface in the absorption spectrum region. This generates a plasmon-induced resonance energy transfer at the positive electrode, producing electron-hole pairs. The electrons are transferred to the negative electrode to form a photocurrent. Through the superposition of photogenerated electrons and the secondary battery itself, the total number of electrons released for external use is increased, thereby improving the specific capacity of the secondary battery.

[0037] In this invention, when plasma-reinforced lithium-containing semiconductor material is used as the positive electrode, when the plasmon energy is higher than the band gap of the lithium-containing semiconductor material, the light absorption in the positive electrode is enhanced, broadband light absorption is achieved, the transport of electrons and ions inside the positive electrode and the charge transfer at the electrode / electrolyte interface are promoted, and the efficiency of the positive electrode is improved.

[0038] As alternative examples, lithium-free semiconductor materials with plasma effects include vanadium pentoxide (V2O5), molybdenum oxide (MoO3), and tungsten oxide (WO3).

[0039] As an optional example, the plasma-composite lithium-containing semiconductor material is LiCoO2 doped with Ag nanoparticles, LiCoO2 doped with Au nanoparticles, or LiCoO2 doped with Ru nanoparticles.

[0040] Preferably, in the plasma-conjugated lithium-containing semiconductor material, the doping amount of Ag, Au, or Ru nanoparticles in oxide or salt form is 0.5 wt.% to 5 wt.%.

[0041] It should be understood that the plasma-reinforced lithium-containing semiconductor material mentioned above includes, but is not limited to, LiCoO2, and may also be lithium-containing semiconductor materials such as lithium cobalt oxide and lithium manganese oxide; the doping material includes, but is not limited to, Ag nanoparticles, and may also be noble metal nanoparticles with plasma effect such as Au or Ru nanoparticles. It only needs to satisfy that the wavelength of the response light completely or partially overlaps with that of the doped lithium-containing semiconductor, so that it can generate a plasma effect under illumination and improve the electrochemical performance of the lithium-containing semiconductor material used by doping.

[0042] As a representative example, the plasma-reinforced lithium-containing semiconductor material is preferably LiCoO2 doped with Ag nanoparticles. For example... Figure 3 As shown, the light absorption intensity of LiCoO2 changes rapidly in the 200-500 nm wavelength range, indicating that LiCoO2 has a drastic response to light illumination in the 200-500 nm range; its band gap is approximately 2.2 eV (e.g., ...). Figure 4 As shown in the figure, corresponding to the 500nm band, when the energy of the irradiated light is greater than the band gap, that is, when the irradiated band is less than 500nm, a photoresponse will occur, an electron transition will occur, and photogenerated electrons and holes will be generated.

[0043] Meanwhile, the light absorption band of nano-Ag is 390-410nm, which is within the band of LiCoO2 response. Therefore, light in the 200-500nm band can satisfy the response range of both LiCoO2 and nano-Ag.

[0044] In practical applications, the 200-500nm wavelength range is partially included in the visible light wavelength range. Therefore, under visible light conditions (400-760nm wavelength range), the positive electrode of LiCoO2 doped with Ag nanoparticles can still respond and meet the requirements of practical applications.

[0045] As an example, the preparation method of the plasma composite lithium-containing semiconductor material cathode of the present invention includes the following specific steps:

[0046] (1) Add appropriate amounts of AgNO3, Au2O3 or RuO4 to LiCoO2 to obtain a mixture. Put the mixture into a ball mill and stir for a certain time. Then put it into a muffle furnace for calcination to obtain LiCoO2 doped with Ag, Au or Ru nanoparticles.

[0047] (2) Mix LiCoO2 doped with Ag, Au or Ru nanoparticles, binder and conductive agent in proportion, stir evenly and then coat the mixture evenly on the surface of the mesh positive electrode current collector. After drying, cut into round pieces to obtain a plasma composite lithium semiconductor material positive electrode suitable for bulk solid-state batteries; or use magnetron sputtering to deposit LiCoO2 doped with Ag, Au or Ru nanoparticles as a positive electrode film on the surface of FTO conductive glass substrate to obtain a plasma composite lithium semiconductor material positive electrode suitable for solid-state thin-film batteries.

[0048] Preferably, in step (1), the mass ratio of LiCoO2 to AgNO3, Au2O3 or RuO4 is (200-20):1, the stirring time is ≥12h, the calcination temperature is 500~800℃, and the calcination time is 5~8h.

[0049] Preferably, in step (2), the mass ratio of LiCoO2 doped with Ag, Au or Ru nanoparticles, binder and conductive agent is (7-8):(1-2):1, the diameter of the disc is 12-13 mm, and the drying temperature is 60-90℃.

[0050] Preferably, in step (2), the thickness of the positive electrode film is 0.5 ± 0.1 μm.

[0051] As an example, such as Figure 1 As shown, the light-assisted plasma-enhanced photoelectric secondary battery of the present invention is a bulk solid-state battery, comprising, from top to bottom: a positive electrode shell 12, a mesh positive electrode current collector 13, a positive electrode 14 made of plasma-composite lithium-containing semiconductor material or lithium-free semiconductor material with its own plasma effect, a solid electrolyte 15, a negative electrode 16, and a negative electrode shell 17. The positive electrode shell is provided with an optical window 11. The positive and negative electrode shells serve to protect and fix the battery, and can be press-fitted using a press. Thus, incident light passes through the optical window 11 and through the mesh positive electrode current collector 13, and then onto the positive electrode 14.

[0052] As an optional example, the mesh positive electrode current collector can be an aluminum mesh, a carbon fiber mesh, a carbon-coated aluminum mesh, etc., with a carbon-coated aluminum mesh being a representative embodiment.

[0053] As an optional example, the solid electrolyte is lithium lanthanum zirconium oxide (LLZO), lithium phosphorus oxynitrogen (LiPON), etc., with LLZO used in the representative embodiment.

[0054] As an alternative example, the negative electrode is the metal Li.

[0055] As an example, the assembly method of a bulk solid-state battery based on light-assisted plasma-enhanced photoelectric performance is as follows: In a glove box, materials are placed sequentially from bottom to top, and then removed after being pressed by a press.

[0056] Preferably, the oxygen pressure in the glove box is <0.5ppm and the moisture content is <0.5ppm; the pressure of the press is 10-15MPa and the pressurization time is 30-60s.

[0057] As an example, such as Figure 2 As shown, the light-assisted plasma-enhanced photoelectric secondary battery of the present invention is a solid-state thin-film battery, which includes, from bottom to top: a transparent conductive substrate 21, a positive electrode thin film 22 of plasma-composite lithium-containing semiconductor material or lithium-free semiconductor material with plasma effect, a solid electrolyte thin film 23, a negative electrode thin film 24, and a negative electrode current collector 25.

[0058] As an optional example, the transparent conductive substrate is FTO conductive glass, the solid electrolyte film is LLZO film, the negative electrode film is metallic Li film, and the negative electrode current collector is metallic Cu.

[0059] As an example, the assembly method of a solid-state thin-film battery with photo-assisted plasma-enhanced photoelectric performance is as follows:

[0060] First, magnetron sputtering is used to deposit an LLZO solid electrolyte film on a plasma composite lithium-containing semiconductor material or a lithium-free semiconductor material with its own plasma effect on an FTO conductive glass substrate. Then, a metal Li film is deposited as the negative electrode using vacuum evaporation. Finally, Cu is deposited as the negative electrode current collector film using magnetron sputtering.

[0061] The present invention will be further described in detail below with reference to specific embodiments and accompanying drawings. Unless otherwise specified, the experimental methods described in the following embodiments are conventional methods; the reagents and materials described are commercially available unless otherwise specified.

[0062] solid-state batteries

[0063] Example 1

[0064] (1) 7.5 mg AgNO3 was added to 1.5 g LiCoO2 to obtain a mixture. The mixture was placed in a ball mill and stirred for 12 h. Then it was placed in a muffle furnace at 800 °C and calcined for 5 h to obtain LiCoO2 cathode material doped with Ag nanoparticles. The doping amount of AgNO3 was 0.5 wt.%.

[0065] (2) Place 80mg of the positive electrode material and 10mg of the conductive agent Super P from (1) into an agate mortar. At the same time, place a stirring bottle containing a magnetic needle on a stirrer. Add four drops of solvent N-methylpyrrolidone (NMP) into the stirring bottle, and then slowly add 10mg of binder polyvinylidene fluoride (PVDF). Then grind the powder in the agate mortar for 30 minutes. After grinding, slowly pour it into the stirring bottle and add five drops of NMP. After stirring for 8 hours, the mixture is evenly coated on the positive electrode current collector. After drying in a vacuum oven at 80°C, it is cut into 12mm round pieces as the positive electrode.

[0066] (3) In the glove box, place the positive electrode shell, the positive electrode obtained in step (2), the solid electrolyte, the negative electrode, and the negative electrode shell in order from bottom to top, and apply a pressure of 10 MPa using a press, press for 30 seconds and then take it out; wherein, the oxygen pressure in the glove box is <0.5 ppm and the moisture content is <0.5 ppm.

[0067] Example 2

[0068] (1) 10 mg AgNO3 was added to 1.5 g LiCoO2 to obtain a mixture. The mixture was put into a ball mill and stirred for 12 h. Then it was calcined in a muffle furnace at 800 °C for 5 h to obtain LiCoO2 doped with Ag nanoparticles. The doping amount of AgNO3 was 0.7 wt.%.

[0069] (2) Place 80mg of the positive electrode material and 10mg of conductive carbon black (super p) from (1) into an agate mortar. At the same time, place a stirring bottle containing a magnetic needle on a stirrer. Add four drops of solvent NMP into the stirring bottle, and then slowly add 10mg of binder PVDF. After that, grind the powder in the agate mortar for 30 minutes. After grinding, slowly pour it into the stirring bottle and add five drops of NMP. After stirring for 8 hours, the mixture is evenly coated on the positive electrode current collector and dried in a vacuum oven at 80°C. Then cut it into 12mm round pieces.

[0070] (3) In the glove box, place the positive electrode shell, the positive electrode obtained in step (2), the solid electrolyte, the negative electrode, and the negative electrode shell in order from bottom to top, and apply a pressure of 10 MPa using a press, press for 30 seconds and then take it out; wherein, the oxygen pressure in the glove box is <0.5 ppm and the moisture content is <0.5 ppm.

[0071] Example 3

[0072] (1) 15 mg Au2O3 was added to 1.5 g LiCoO2 to obtain a mixture. The mixture was put into a ball mill and stirred for 12 h. Then it was calcined in a muffle furnace at 800 °C for 5 h to obtain LiCoO2 cathode material doped with Au nanoparticles. The doping amount of Au2O3 was 1 wt.%.

[0073] (2) Place 80mg of the positive electrode material and 10mg of the conductive agent Super P from (1) into an agate mortar. At the same time, place a stirring bottle containing a magnetic needle on a mixer. Add four drops of solvent NMP into the stirring bottle, and then slowly add 10mg of binder PVDF. After that, grind the powder in the agate mortar for 30 minutes. After grinding, slowly pour it into the stirring bottle and add five drops of NMP. After stirring for 8 hours, the mixture is evenly coated on the positive electrode current collector and dried in an 80°C vacuum oven before being cut into 12mm round pieces.

[0074] (3) In the glove box, place the positive electrode shell, the positive electrode obtained in step (2), the solid electrolyte, the negative electrode, and the negative electrode shell in order from bottom to top, and apply a pressure of 10 MPa using a press, press for 30 seconds and then take it out; wherein, the oxygen pressure in the glove box is <0.5 ppm and the moisture content is <0.5 ppm.

[0075] Example 4

[0076] (1) 30 mg RuO4 was added to 1.5 g LiCoO2 to obtain a mixture. The mixture was put into a ball mill and stirred for 12 h. Then it was calcined in a muffle furnace at 800 °C for 5 h to obtain LiCoO2 doped with Ru nanoparticles. The doping amount of RuO4 was 2 wt.%.

[0077] (2) Place 80mg of the positive electrode material and 10mg of the conductive agent Super P from (1) into an agate mortar. At the same time, place a stirring bottle containing a magnetic needle on a mixer. Add four drops of solvent NMP into the stirring bottle, and then slowly add 10mg of binder PVDF. After that, grind the powder in the agate mortar for 30 minutes. After grinding, slowly pour it into the stirring bottle and add five drops of NMP. After stirring for 8 hours, the mixture is evenly coated on the positive electrode current collector and dried in an 80°C vacuum oven before being cut into 12mm round pieces.

[0078] (3) In the glove box, place the positive electrode shell, the positive electrode obtained in step (2), the solid electrolyte, the negative electrode, and the negative electrode shell in order from bottom to top, and apply a pressure of 10 MPa using a press, press for 30 seconds and then take it out; wherein, the oxygen pressure in the glove box is <0.5 ppm and the moisture content is <0.5 ppm.

[0079] Example 5

[0080] (1) 75 mg AgNO3 was added to 1.5 g LiCoO2 to obtain a mixture. The mixture was placed in a ball mill and stirred for 12 h. Then it was placed in a muffle furnace at 800 °C and calcined for 5 h to obtain LiCoO2 doped with Ag nanoparticles. The doping amount of AgNO3 was 5 wt.%.

[0081] (2) Place 80mg of the positive electrode material and 10mg of the conductive agent Super P from (1) into an agate mortar. At the same time, place a stirring bottle containing a magnetic needle on a mixer. Add four drops of solvent NMP into the stirring bottle, and then slowly add 10mg of binder PVDF. After that, grind the powder in the agate mortar for 30 minutes. After grinding, slowly pour it into the stirring bottle and add five drops of NMP. After stirring for 8 hours, the mixture is evenly coated on the positive electrode current collector and dried in an 80°C vacuum oven before being cut into 12mm round pieces.

[0082] (3) In the glove box, place the positive electrode shell, the positive electrode obtained in step (2), the solid electrolyte, the negative electrode, and the negative electrode shell in order from bottom to top, and apply a pressure of 10 MPa using a press, press for 30 seconds and then take it out; wherein, the oxygen pressure in the glove box is <0.5 ppm and the moisture content is <0.5 ppm.

[0083] Solid-state thin-film batteries

[0084] Example 6

[0085] (1) 7.5 mg AgNO3 was added to 1.5 g LiCoO2 to obtain a mixture. The mixture was put into a ball mill and stirred for 12 h. Then it was calcined in a muffle furnace at 800 °C for 5 h to obtain LiCoO2 doped with Ag nanoparticles. The doping amount of AgNO3 was 0.5 wt.%.

[0086] (2) Preparation of FTO conductive glass positive electrode film

[0087] FTO conductive glass (a combination of glass and FTO thin film) was placed in working chamber A, and a positive electrode film was sputtered and deposited. DC reactive magnetron sputtering was used, with high-purity modified LiCoO2 as the target material (purity >99%), high-purity Ar and high-purity O2 as the sputtering gases, a working pressure of 0.6 Pa, and a sputtering power of 80 W. The LiCoO2 positive electrode film doped with Ag nanoparticles was sputtered and deposited, with a thickness controlled at 0.5 ± 0.1 μm.

[0088] (3) Preparation of solid electrolyte thin films by magnetron sputtering

[0089] The above sample was transferred to working chamber B, and solid electrolyte films were sputtered and deposited. Magnetron sputtering was used with high-purity LLZO as the target material (purity >99.9%), high-purity N2 as the sputtering gas, working pressure of 0.9 Pa, sputtering power of 90 W, and LLZO films were sputtered and deposited with a thickness controlled between 1.5 and 3 μm.

[0090] (4) Preparation of negative electrode thin film

[0091] The sample was transferred to the working chamber for further vacuum deposition of a Li anode film. Using high-purity Li metal sheets as raw material, a Li anode film was deposited via vacuum deposition, with a thickness controlled at 10 μm. The lithium metal evaporation source was then turned off, and the sample was removed.

[0092] (5) Preparation of negative electrode current collector thin film

[0093] The sample was transferred to working chamber B, and the negative electrode current collector film was deposited by sputtering. The magnetron sputtering method was used with high-purity metal Cu as the target material (purity >99.9%), high-purity Ar as the sputtering gas, the working pressure was 0.6 Pa, the sputtering power was 60 W, and the Cu film was deposited by sputtering with a thickness of about 0.5 μm.

[0094] Example 7

[0095] (1) 10 mg Au2O3 was added to 1.5 g LiCoO2 to obtain a mixture. The mixture was put into a ball mill and stirred for 12 h. Then it was calcined in a muffle furnace at 800 °C for 5 h to obtain LiCoO2 doped with Au nanoparticles. The doping amount of Au2O3 was 0.7 wt.%.

[0096] (2) Preparation of FTO conductive glass positive electrode film

[0097] FTO conductive glass (a combination of glass and FTO thin film) was placed in working chamber A, and a positive electrode film was sputtered and deposited. DC reactive magnetron sputtering was used, with high-purity modified LiCoO2 as the target material (purity >99%), high-purity Ar and high-purity O2 as the sputtering gases, a working pressure of 0.6 Pa, and a sputtering power of 80 W. The LiCoO2 positive electrode film doped with Au nanoparticles was sputtered and deposited, with a thickness controlled at 0.5 ± 0.1 μm.

[0098] (3) Preparation of solid electrolyte thin films by magnetron sputtering

[0099] The above sample was transferred to working chamber B, and solid electrolyte films were sputtered and deposited. Magnetron sputtering was used with high-purity LLZO as the target material (purity >99.9%), high-purity N2 as the sputtering gas, working pressure of 0.9 Pa, sputtering power of 90 W, and LLZO films were sputtered and deposited with a thickness controlled between 1.5 and 3 μm.

[0100] (4) Preparation of negative electrode thin film

[0101] The sample was transferred to the working chamber for further vacuum deposition of a Li anode film. Using high-purity Li metal sheets as raw material, a Li anode film was deposited via vacuum deposition, with a thickness controlled at 10 μm. The lithium metal evaporation source was then turned off, and the sample was removed.

[0102] (5) Preparation of negative electrode current collector thin film

[0103] The sample was transferred to working chamber B, and the negative electrode current collector film was deposited by sputtering. The magnetron sputtering method was used with high-purity metal Cu as the target material (purity >99.9%), high-purity Ar as the sputtering gas, the working pressure was 0.6 Pa, the sputtering power was 60 W, and the Cu film was deposited by sputtering with a thickness of about 0.5 μm.

[0104] Example 8

[0105] (1) 15 mg AgNO3 was added to 1.5 g LiCoO2 to obtain a mixture. The mixture was put into a ball mill and stirred for 12 h. Then it was calcined in a muffle furnace at 800 °C for 5 h to obtain LiCoO2 doped with Ag nanoparticles. The doping amount of AgNO3 was 1 wt.%.

[0106] (2) Preparation of FTO conductive glass positive electrode film

[0107] FTO conductive glass (a combination of glass and FTO thin film) was placed in working chamber A, and a positive electrode film was sputtered and deposited. DC reactive magnetron sputtering was used, with high-purity modified LiCoO2 as the target material (purity >99%), high-purity Ar and high-purity O2 as the sputtering gases, a working pressure of 0.6 Pa, and a sputtering power of 80 W. The LiCoO2 positive electrode film doped with Ag nanoparticles was sputtered and deposited, with a thickness controlled at 0.5 ± 0.1 μm.

[0108] (3) Preparation of solid electrolyte thin films by magnetron sputtering

[0109] The above sample was transferred to working chamber B, and solid electrolyte films were sputtered and deposited. Magnetron sputtering was used with high-purity LLZO as the target material (purity >99.9%), high-purity N2 as the sputtering gas, working pressure of 0.9 Pa, sputtering power of 90 W, and LLZO films were sputtered and deposited with a thickness controlled between 1.5 and 3 μm.

[0110] (4) Preparation of negative electrode thin film

[0111] The sample was transferred to the working chamber for further vacuum deposition of a Li anode film. Using high-purity Li metal sheets as raw material, a Li anode film was deposited via vacuum deposition, with a thickness controlled at 10 μm. The lithium metal evaporation source was then turned off, and the sample was removed.

[0112] (5) Preparation of negative electrode current collector thin film

[0113] The sample was transferred to working chamber B, and the negative electrode current collector film was deposited by sputtering. The magnetron sputtering method was used with high-purity metal Cu as the target material (purity >99.9%), high-purity Ar as the sputtering gas, the working pressure was 0.6 Pa, the sputtering power was 60 W, and the Cu film was deposited by sputtering with a thickness of about 0.5 μm.

[0114] Example 9

[0115] (1) 30 mg AgNO3 was added to 1.5 g LiCoO2 to obtain a mixture. The mixture was put into a ball mill and stirred for 12 h. Then it was calcined in a muffle furnace at 800 °C for 5 h to obtain LiCoO2 doped with Ag nanoparticles. The doping amount of AgNO3 was 2 wt.%.

[0116] (2) Preparation of FTO conductive glass positive electrode film

[0117] FTO conductive glass (a combination of glass and FTO thin film) was placed in working chamber A, and a positive electrode film was sputtered and deposited. DC reactive magnetron sputtering was used, with high-purity modified LiCoO2 as the target material (purity >99%), high-purity Ar and high-purity O2 as the sputtering gases, a working pressure of 0.6 Pa, and a sputtering power of 80 W. The LiCoO2 positive electrode film doped with Ag nanoparticles was sputtered and deposited, with a thickness controlled at 0.5 ± 0.1 μm.

[0118] (3) Preparation of solid electrolyte thin films by magnetron sputtering

[0119] The above sample was transferred to working chamber B, and solid electrolyte films were sputtered and deposited. Magnetron sputtering was used with high-purity LLZO as the target material (purity >99.9%), high-purity N2 as the sputtering gas, working pressure of 0.9 Pa, sputtering power of 90 W, and LLZO films were sputtered and deposited with a thickness controlled between 1.5 and 3 μm.

[0120] (4) Preparation of negative electrode thin film

[0121] The sample was transferred to the working chamber for further vacuum deposition of a Li anode film. Using high-purity Li metal sheets as raw material, a Li anode film was deposited via vacuum deposition, with a thickness controlled at 10 μm. The lithium metal evaporation source was then turned off, and the sample was removed.

[0122] (5) Preparation of negative electrode current collector thin film

[0123] The sample was transferred to working chamber B, and the negative electrode current collector film was deposited by sputtering. The magnetron sputtering method was used with high-purity metal Cu as the target material (purity >99.9%), high-purity Ar as the sputtering gas, the working pressure was 0.6 Pa, the sputtering power was 60 W, and the Cu film was deposited by sputtering with a thickness of about 0.5 μm.

[0124] Example 10

[0125] (1) 75 mg RuO4 was added to 1.5 g LiCoO2 to obtain a mixture. The mixture was placed in a ball mill and stirred for 12 h. Then it was placed in a muffle furnace at 800 °C and calcined for 5 h to obtain LiCoO2 doped with Ru nanoparticles. The doping amount of RuO4 was 5 wt.%.

[0126] (2) Preparation of FTO conductive glass positive electrode film

[0127] FTO conductive glass (a combination of glass and FTO thin film) was placed in working chamber A, and a positive electrode film was sputtered and deposited. DC reactive magnetron sputtering was used, with high-purity modified LiCoO2 as the target material (purity >99%), high-purity Ar and high-purity O2 as the sputtering gases, a working pressure of 0.6 Pa, and a sputtering power of 80 W. A LiCoO2 positive electrode film doped with Ru nanoparticles was sputtered and deposited, with a thickness controlled at 0.5 ± 0.1 μm.

[0128] (3) Preparation of solid electrolyte thin films by magnetron sputtering

[0129] The above sample was transferred to working chamber B, and solid electrolyte films were sputtered and deposited. Magnetron sputtering was used with high-purity LLZO as the target material (purity >99.9%), high-purity N2 as the sputtering gas, working pressure of 0.9 Pa, sputtering power of 90 W, and LLZO films were sputtered and deposited with a thickness controlled between 1.5 and 3 μm.

[0130] (4) Preparation of negative electrode thin film

[0131] The sample was transferred to the working chamber for further vacuum deposition of a Li anode film. Using high-purity Li metal sheets as raw material, a Li anode film was deposited via vacuum deposition, with a thickness controlled at 10 μm. The lithium metal evaporation source was then turned off, and the sample was removed.

[0132] (5) Preparation of negative electrode current collector thin film

[0133] The sample was transferred to working chamber B, and the negative electrode current collector film was deposited by sputtering. The magnetron sputtering method was used with high-purity metal Cu as the target material (purity >99.9%), high-purity Ar as the sputtering gas, the working pressure was 0.6 Pa, the sputtering power was 60 W, and the Cu film was deposited by sputtering with a thickness of about 0.5 μm.

[0134] Example 11

[0135] (1) Preparation of FTO conductive glass positive electrode film

[0136] FTO conductive glass (a combination of glass and FTO thin film) was placed in working chamber A, and a positive electrode film was sputtered and deposited. DC reactive magnetron sputtering was used, with high-purity MoO3 as the target material (purity >99%), high-purity Ar and high-purity O2 as the sputtering gases, a working pressure of 0.6 Pa, and a sputtering power of 80 W. The MoO3 positive electrode film was sputtered and deposited with a thickness controlled at 0.5 ± 0.1 μm.

[0137] (2) Preparation of solid electrolyte thin films by magnetron sputtering

[0138] The above sample was transferred to working chamber B, and solid electrolyte films were sputtered and deposited. Magnetron sputtering was used with high-purity LLZO as the target material (purity >99.9%), high-purity N2 as the sputtering gas, working pressure of 0.9 Pa, sputtering power of 90 W, and LLZO films were sputtered and deposited with a thickness controlled between 1.5 and 3 μm.

[0139] (3) Preparation of negative electrode thin film

[0140] The sample was transferred to the working chamber for further vacuum deposition of a Li anode film. Using high-purity Li metal sheets as raw material, a Li anode film was deposited via vacuum deposition, with a thickness controlled at 10 μm. The lithium metal evaporation source was then turned off, and the sample was removed.

[0141] (4) Preparation of negative electrode current collector thin film

[0142] The sample was transferred to working chamber B, and the negative electrode current collector film was deposited by sputtering. The magnetron sputtering method was used with high-purity metal Cu as the target material (purity >99.9%), high-purity Ar as the sputtering gas, the working pressure was 0.6 Pa, the sputtering power was 60 W, and the Cu film was deposited by sputtering with a thickness of about 0.5 μm.

[0143] Figure 5 These are the constant current charge-discharge curves of the battery prepared in Example 6 under both light and dark conditions. After several cycles, the discharge specific capacity was 89 mA / g without light. However, after adding light, the discharge specific capacity increased to 92 mA / g. Clearly, compared to conventional LiCoO2 cathode materials containing Ag nanoparticles without light, applying light significantly improves the battery's specific capacity and stability. The battery obtained in Example 11 was used as the test object, and its electrochemical performance was tested. The results are as follows... Figure 6 As shown. From Figure 6As can be seen from the graph, at a current density of 200 mA / g, after 119 cycles without light exposure (curve position 1 in the graph), the specific capacity of the first cycle is as high as 290 mAh / g, even higher than the theoretical battery capacity of 273.8 mAh / g. The specific capacity after 119 cycles is 164.4 mAh / g. Then, after 120-130 cycles with light exposure (curve position 2 in the graph), the specific capacity rapidly increases to about 217 mAh / g. After 131-150 cycles without light exposure (curve position 1 in the graph), the specific capacity increases rapidly to about 217 mAh / g. At point 3, the specific capacity decreased to 160 mAh / g; after 151-160 cycles with the same illumination (curve position 4 in the figure), the specific capacity increased to 218 mAh / g; after 160-180 cycles with illumination stopped, the specific capacity was approximately 165 mAh / g (curve position 5 in the figure); after 180-190 cycles with illumination, the specific capacity was approximately 205 mAh / g (curve position 6 in the figure); after 191-250 cycles with illumination stopped, the specific capacity decreased to approximately 140 mAh / g (curve position 7 in the figure). Clearly, compared to conventional LiCoO2 cathode materials containing Ag nanoparticles that are not illuminated throughout the cycle, applying illumination can significantly improve the battery's specific capacity and stability. Figure 7 This is a rate performance graph of the battery in Example 11. As can be seen from the graph, the battery specific capacity changes when different current densities are applied under light or darkness. Initially, with a current density of 200 mA / g, the specific capacity reaches 297 mAh / g under light conditions and 149.8 mAh / g under darkness. Then, with a lower current density of 50 mA / g, the battery specific capacity increases under both light and darkness conditions, reaching 350 mAh / g under light conditions and a maximum of 329.87 mAh / g under darkness. When the current density is increased to 100 mA / g, the maximum specific capacity is 295.6 mAh / g under light conditions and 243.7 mAh / g under darkness. Returning to the initial current density of 200 mA / g, the specific capacity is 237.6 mAh / g under light conditions and only 182.1 mAh / g under darkness.

[0144] The present invention is represented by Example 11. The specific capacity of the battery of the present invention is effectively improved, with a specific capacity between 205 mAh / g and 290 mAh / g; its specific capacity in the first cycle is even higher than the maximum actual specific capacity of molybdenum oxide batteries currently studied, reaching as high as 290 mAh / g.

[0145] The present invention is represented by Example 6, in which the specific capacity of the battery after several cycles was 89 mAh / g, and the specific capacity increased to 92 mAh / g after applying light. The performance of the batteries prepared in other examples is roughly the same as that of the examples under both light and no light conditions, all showing that the specific capacity is effectively improved after light exposure.

[0146] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A secondary battery based on light-assisted plasma-enhanced photoelectric performance, characterized in that, Plasma-composite lithium-containing semiconductor material is used as the positive electrode. The plasma-composite lithium-containing semiconductor material is obtained by doping lithium-containing semiconductor material with nanomaterials that have plasma effect. The nanomaterials with plasma effect and lithium-containing semiconductor material have completely or partially overlapping light response ranges. The positive electrode shell of the secondary battery is provided with an optical window or the substrate of the positive electrode film is transparent. The plasma-composite lithium-containing semiconductor material is LiCoO2 doped with Ag nanoparticles, LiCoO2 doped with Au nanoparticles, or LiCoO2 doped with Ru nanoparticles.

2. The secondary battery according to claim 1, characterized in that, The positive electrode is in the form of a thin film or sheet, and the light-transmitting substrate is a mesh current collector used in bulk solid-state batteries or FTO conductive glass used in solid-state thin-film batteries.

3. The secondary battery according to claim 1, characterized in that, The positive electrode is prepared by the following methods: a sheet-like positive electrode is made by uniformly coating a plasma composite lithium-containing semiconductor material, a binder and a conductive agent mixed in proportion and then coated on the surface of a mesh positive electrode current collector, or a thin film-like positive electrode is deposited by magnetron sputtering of a plasma composite lithium-containing semiconductor material onto the surface of an FTO conductive glass.

4. The secondary battery according to claim 3, characterized in that, The method for preparing the positive electrode includes the following steps: A positive electrode is obtained by modifying a translucent substrate surface with a plasma-conjugated lithium-containing semiconductor material; wherein the plasma-conjugated lithium-containing semiconductor material is prepared through the following steps: A lithium-containing semiconductor material is uniformly mixed with a precursor of a nanomaterial with a plasma effect, and then calcined to obtain a plasma-composite lithium-containing semiconductor material. The precursor of the nanomaterial with a plasma effect is an oxide or salt of a metal with a plasma effect.

5. The secondary battery according to claim 1, characterized in that, It is a solid-state thin-film battery or a bulk solid-state battery.

6. The secondary battery according to claim 5, characterized in that, The solid-state battery comprises, from top to bottom: a positive electrode shell, a plasma-composite lithium-containing semiconductor material positive electrode, a solid electrolyte, a negative electrode, and a negative electrode shell, wherein the positive electrode shell is provided with an optical window.

7. The secondary battery according to claim 5, characterized in that, The solid-state thin-film battery comprises, from bottom to top: an FTO conductive glass substrate, a plasma-composite lithium-containing semiconductor material positive electrode film, a solid electrolyte film, a negative electrode film, and a negative electrode current collector film.

Images