阅读说明：本技术 一种太阳能辅助节能充电型有机锂硫电池 (Solar energy-assisted energy-saving rechargeable organic lithium-sulfur battery ) 是由 李娜 王艳君 王悦岚 孙旭东 于 2019-10-16 设计创作，主要内容包括：本发明涉及太阳能至电能的转化和存储领域,具体为一种太阳能辅助节能充电型有机锂硫电池。太阳能辅助充电有机锂硫电池包括固体硫或多硫离子溶液正极、锂负极及半导体光电极。在光照充电时,半导体光电极受光激发产生光生电子和空穴,价带中空穴将多硫离子氧化,而光生电子将通过外电路还原金属锂,光电极产生的光电压部分补偿充电电压,降低充电电压,实现节省电能的目的,同时实现太阳能至电能的转化存储。本发明提出一种高效稳定的太阳能可充电锂硫电池,制备方法简单、工艺条件温和,成本低,满足工业生产要求。(The invention relates to the field of conversion and storage from solar energy to electric energy, in particular to a solar energy-assisted energy-saving rechargeable organic lithium-sulfur battery. The solar auxiliary charging organic lithium-sulfur battery comprises a solid sulfur or polysulfide ion solution positive electrode, a lithium negative electrode and a semiconductor photoelectrode. When the solar photovoltaic battery is charged by illumination, a semiconductor photoelectrode is excited by light to generate photogenerated electrons and holes, the holes in a valence band oxidize polysulfide ions, the photogenerated electrons reduce metal lithium through an external circuit, the photovoltage generated by the photoelectrode partially compensates charging voltage, the charging voltage is reduced, the purpose of saving electric energy is achieved, and meanwhile conversion and storage from solar energy to electric energy are achieved. The invention provides a high-efficiency stable solar rechargeable lithium-sulfur battery, which is simple in preparation method, mild in process conditions and low in cost, and meets the requirements of industrial production.)

1. The solar energy-assisted energy-saving rechargeable organic lithium-sulfur battery is characterized in that metal lithium is used as a negative electrode, solid sulfur or polysulfide ion solution is used as a positive electrode, the photoelectrode is a semiconductor photoelectrode material, and ether solution containing lithium salt is used as electrolyte, so that the solar energy-assisted energy-saving rechargeable organic lithium-sulfur battery is formed.

2. The solar-assisted energy-saving rechargeable organic lithium-sulfur battery as claimed in claim 1, wherein the positive electrode is solid sulfur, lithium sulfide, or Li₂S_n(1<n<8) Or a composite thereof.

3. The solar-assisted energy-saving rechargeable organolithium sulfur battery according to claim 2, wherein the positive electrode composite comprises a carbon material, an organic polymer or a transition metal sulfide material.

4. The solar-assisted energy-saving rechargeable organic lithium-sulfur battery as claimed in claim 1, wherein the electrolyte is an organic ether electrolyte containing lithium bistrifluoromethane succinimide, the molar concentration of the lithium bistrifluoromethane succinimide is 1-10M, and the organic ether comprises ethylene glycol dimethyl ether, dimethyl sulfoxide, tetrahydrofuran, dioxolane or tetraethylene glycol dimethyl ether.

5. The solar-assisted energy-saving rechargeable organolithium sulfur battery according to claim 1, wherein the battery comprises a lithium-sulfur cell and a lithium-sulfur cellThe photoelectrode material is ZnS, CdS, C₃N₄、SrTiO₃Or TiO₂。

6. The solar-assisted energy-saving rechargeable organic lithium sulfur battery as claimed in claim 5, wherein the photoelectrode base material is Ti, Al, Cu, ITO or FTO.

Technical Field

The invention relates to the field of conversion and storage from solar energy to electric energy, in particular to a solar energy-assisted energy-saving rechargeable organic lithium-sulfur battery.

Background

Efficient storage and utilization of solar energy is one of the effective ways to alleviate the energy crisis and environmental pollution problems currently facing the world. The construction of efficient solar rechargeable batteries is a new trend in the field of energy storage. The solar rechargeable lithium ion battery is divided into two types according to the construction mode: 1) the photovoltaic cell integrated battery integrates a photovoltaic cell (including a dye-sensitized solar cell or a perovskite solar cell) into a traditional lithium ion battery or a capacitor, and the photovoltaic cell converts solar energy into electric energy to charge the battery or the capacitor in the illumination process. The discharge capacity of such devices reported to date is low, such as: the discharge capacity of the light rechargeable battery reported by Guo et al [12] is only 38.89 mu Ah, and the discharge capacity can not reach the capacity level of a commercial lithium ion battery, and can not meet the requirement of solar energy mass storage (W.X.Guo, X.Y.Xue, S.H.Wang, C.J.Lin, Z.L.Wang.Nano Lett.2012,12,2520). In addition, because the voltage of the solar photovoltaic cell is low, 4-10 solar photovoltaic cells are often required to be connected in series to meet the charging voltage of the lithium ion battery, the weight of the device is increased, the portability is reduced, and the technical difficulty and the processing cost of the device are increased; 2) a photoelectrode-implanted battery, Yu in the united states, etc., constitutes a novel photoelectrode-implanted solar-assisted rechargeable battery, and its structure is simpler than the former (m.z.yu, x.d.ren, l.ma, y.y.wu. _ nat. commun.2014,5,5111). A semiconductor photoelectrode with a proper band edge position is implanted into a battery system, and when the photoelectrode is illuminated, the photoelectrode absorbs photons with energy higher than a band gap, electrons in a valence band are excited to a conduction band, and holes are generated in the valence band. The positive electrode material adsorbed on the surface of the material is oxidized by the diffusion of holes in the valence band to the surface of the material, and the negative electrode material is reduced by the diffusion of electrons on the conduction band to the negative electrode through an external circuit under the assistance of voltage. In the process, the photovoltage generated by the photoelectrode compensates for part of the charging voltage, thereby reducing the charging voltage. The input of electric energy can be saved when the battery is charged by simply introducing the photoelectrode, the conversion and the storage of solar energy to electric energy are indirectly realized, and a new thought is provided for designing and developing novel high-efficiency solar rechargeable batteries.

The lithium-sulfur battery is a novel high-capacity energy storage system with great development prospect, has the outstanding advantages of high theoretical energy density, low cost, environmental protection and the like, and shows wide application prospect in the emerging technical fields of power batteries for new energy automobiles and the like. The theoretical specific capacity of the lithium-sulfur battery is up to 1675mAh g^-1The theoretical specific energy density of the constructed lithium secondary battery system can reach 2600Wh kg^-1Is the current commercial lithium ion3-5 times of the battery, so the development of the solar rechargeable lithium-sulfur battery is an effective means for realizing the mass conversion and storage of solar energy. Through careful analysis of research progress in related fields at home and abroad, few researches on solar-charged lithium-sulfur batteries are carried out so far, and the only report is that a biliquid lithium-sulfur battery capable of converting and storing solar energy is proposed in the early stage. However, when the battery is charged by illumination, the photo-generated electrons are not transferred to the negative electrode to reduce lithium ions into metal lithium, but protons are reduced into hydrogen, so that conversion and storage from solar energy to chemical energy are realized, and the metal lithium is continuously consumed while the solar energy is stored. In addition, the two-liquid system requires Li_1.35Ti_1.75Al_0.25P_2.7Si_0.3O₁₂The (LATP) ceramic diaphragm isolates a water system anode and an organic system cathode, and has the problems of high cost and potential safety hazard.

Disclosure of Invention

The invention aims to provide a solar auxiliary energy-saving charging type organic lithium sulfur battery, which is constructed by implanting a semiconductor photoelectrode into a positive electrode of the lithium sulfur battery so as to realize mass storage of solar energy in the lithium sulfur battery.

The technical scheme of the invention is as follows:

a solar energy auxiliary energy-saving charging type organic lithium sulfur battery is formed by taking metal lithium as a negative electrode, taking solid sulfur or polysulfide ion solution as a positive electrode, taking a photoelectrode as a semiconductor photoelectrode material and taking ether solution containing lithium salt as electrolyte.

The anode of the solar energy auxiliary energy-saving charging type organic lithium-sulfur battery is solid sulfur, lithium sulfide and Li₂S_n(1<n<8) Or a composite thereof.

According to the solar energy-assisted energy-saving rechargeable organic lithium-sulfur battery, the positive electrode composite material comprises a carbon material, an organic polymer or a transition metal sulfide material.

The solar energy-assisted energy-saving rechargeable organic lithium-sulfur battery is characterized in that the electrolyte is an organic ether electrolyte containing bis (trifluoromethane) lithium succinimide, the molar concentration of the bis (trifluoromethane) lithium succinimide is 1-10M, and the organic ether comprises ethylene glycol dimethyl ether, dimethyl sulfoxide, tetrahydrofuran, dioxolane or tetraethylene glycol dimethyl ether.

The solar energy auxiliary energy-saving rechargeable organic lithium sulfur battery has the photoelectrode material of ZnS, CdS and C₃N₄、SrTiO₃Or TiO₂。

The solar energy auxiliary energy-saving rechargeable organic lithium sulfur battery has a photoelectrode base material of Ti, Al, Cu, ITO or FTO.

The design idea of the invention is as follows:

the invention firstly saves the electric energy required by charging the lithium-sulfur battery through solar energy assistance, when in illumination charging, a semiconductor photoelectrode is excited by light to generate photoproduction electrons and holes, and the holes in a valence band are diffused to the surface of a semiconductor to lead S to be generated^2-(or S)₄ ^2-) Ions are oxidized into polysulfide ions, and photo-generated electrons are diffused to the lithium cathode through an external circuit under the assistance of external voltage to reduce the lithium ions into metallic lithium. In the process, the photogenerated voltage generated by the photo-excited semiconductor photoelectrode partially compensates the voltage in the charging process, so that the electric energy required by charging is saved, and the conversion and storage of solar energy are indirectly realized.

The invention has the advantages and beneficial effects that:

1. the key point of the invention is that the photoelectric electrode is introduced into the anode of the traditional lithium-sulfur battery to save the charging point electric energy of the lithium-sulfur battery, when the battery is charged by illumination, the semiconductor photoelectric electrode is excited by light to generate photoproduction electrons and holes, the holes in the valence band oxidize polysulfide ions, and the photoproduction electrons reduce metal lithium through an external circuit, and the photoelectric electrode is simply introduced to save the electric energy input when the battery is charged, thereby providing reference for designing and developing novel high-efficiency solar rechargeable batteries.

2. The invention realizes the direct conversion and storage of solar energy in the large-scale energy storage device lithium sulfur battery and provides guidance for the reasonable utilization of novel renewable energy sources.

Drawings

FIG. 1 is a schematic structural diagram of a solar-assisted energy-saving rechargeable organic lithium-sulfur battery.

Fig. 2 is a graph of the photo-assisted charging and electrochemical charging contrast for a ZnS-based photo-assisted rechargeable battery, wherein: curve 1 represents an Electrochemical charge (Electrochemical charge) curve, and curve 2 represents a Photo-charge (Photo-assisted charge) curve; in the figure, the abscissa Time represents Time (min) and the ordinate Voltage represents Voltage (V).

FIG. 3 Scanning (SEM) picture of ZnS.

Fig. 4 XRD picture of ZnS. In the figure, the abscissa 2 θ represents the diffraction angle (degree), the ordinate Intensity represents the relative Intensity (a.u.), Sphalerite ZnS represents Sphalerite, and Wurtzite ZnS represents Wurtzite.

FIG. 5 SrTiO₃XRD pictures of (a). In the figure, the abscissa 2Theta represents a diffraction angle (°), and the ordinate Intensity represents a relative Intensity (a.u ℃).

FIG. 6 growth of TiO on carbon paper₂SEM pictures of nanoplatelets.

FIG. 7 growth of TiO on carbon paper₂SEM pictures of nanorods.

FIG. 8 TiO growth on titanium mesh₂SEM pictures of nanotubes.

FIG. 9 shows SrTiO₃A ZnS-based photo-assisted charging and electrochemical charging contrast curve for a photo-electrode, wherein: curve 1 represents TiO₂The curve of photo-charging of the nanorod template, curve 2 represents TiO₂The nano-sheet template photo-charging curve, and curve 3 represents the electrochemical charging curve. In the figure, the abscissa Time represents Time (min) and the ordinate Voltage represents Voltage (V).

Detailed Description

In the specific implementation process, the invention relates to a solar energy auxiliary energy-saving charging type organic lithium-sulfur battery, which comprises a solid sulfur or polysulfide ion solution positive electrode, a lithium negative electrode and a semiconductor photoelectrode, wherein the semiconductor photoelectrode is implanted into the positive electrode of the lithium-sulfur battery to construct the solar energy auxiliary charging type organic lithium-sulfur battery so as to realize mass storage of solar energy in the lithium-sulfur battery. During charging by illumination, the semiconductor photoelectrode is excited by light to generate photo-generated electrons and holes, and the holes in the valence band diffuse to the surface of the semiconductor to form S^2-(or S)₄ ^2-) Ion oxidation to polysulfide ion and photogenerationThe electrons diffuse to the lithium negative electrode through an external circuit with the aid of an external voltage to reduce the lithium ions to metallic lithium. The method comprises the following specific steps:

1. the positive electrode is solid sulfur, lithium sulfide or Li₂S_n(1<n<8) And composites thereof, the composites comprising a carbon material, an organic polymer or a transition metal sulfide material.

2. The organic electrolyte is an organic ether electrolyte of lithium bistrifluoromethane yellow imide with the molar concentration of 1-10M, and the organic ether comprises ethylene glycol dimethyl ether, dimethyl sulfoxide, tetrahydrofuran, dioxolane or tetraethylene glycol dimethyl ether.

3. The photoelectrode material is ZnS, CdS, C₃N₄、SrTiO₃Or TiO₂The preparation method comprises hydrothermal, anodic oxidation or magnetron sputtering and the like.

4. The photoelectrode base material is Ti, Al, Cu, ITO or FTO.

The present invention will be described in further detail with reference to the following examples and the accompanying drawings.