Background
The electrochromic is that under the action of an external electric field, a redox reaction is generated in the material or the injection or extraction of charges (electrons or ions) is changed in the molecular structure, so that the optical properties of the material, such as transmittance, absorptivity and reflectivity, are reversibly changed in the visible light, infrared light or ultraviolet light and other regions. The technology has very important application value in the fields of building glass, automobile intelligent color-changing windows, aircraft portholes, color-changing sunglasses, automobile anti-chordal rearview mirrors, information display, military technology and the like.
A typical all-solid-state electrochromic device composition includes: (1) the substrate is the outermost layer of the electrochromic device, is used for supporting and protecting each layer in the device from the influence of external environment, and is generally a transparent flexible substrate or common glass; (2) the conducting layer is used as an electrode material of the electrochromic device and is connected with an external driving electric field; (3) the electrochromic layer, also called a working electrode, is responsible for the electrochromic process; (4) the ion storage layer, also called counter electrode, is used to assist the electron gaining and losing process of the electrochromic layer to play the role of balancing charge, and the electrochromic material with strong ion storage capacity can also be used as the ion storage layer, thereby strengtheningThe modulation depth of the spectrum, the coloring efficiency of the device or the color of the device are improved; (5) an electrolyte layer for transporting ions (such as H) between the electrochromic layer and the ion storage layer+、Li+、Na+) And blocks the action of electrons.
The electrolyte layer is used as an important component of the electrochromic device, and not only is an ion channel required by the electrochromic material during color change ensured, but also a short circuit is not formed between the anode and the cathode. In summary, the electrolyte layer needs to have the following properties: (1) the ion conductivity is high, so that the migration and the transmission of ions are realized; (2) the electron conductivity is low, so that direct electron current in the device is reduced; (3) the material has enough physical and chemical stability, and does not generate side reaction with other functional layers or external environment in the whole working process; (4) the electrochemical stability is good, so that the electrochromic device can stably work under an external driving electric field; (5) the material has high mechanical strength, good film forming property and good adhesion, so as to ensure that the electrochromic device is easy to process, not easy to fall off, impact-resistant and long in service life; (6) the manufacturing cost is low, and the market development is easy; (7) is safe and nontoxic.
Solid lithium ion conductive electrolytes have been widely studied in all-solid-state electrochromic devices, but have disadvantages such as low lithium ion conductivity (affecting the rate of color change) and poor cycle stability. For example, Cogan et al prepared a structure of [ glass (substrate)/indium tin oxide (transparent conductive layer)/LixLiyCrO2+x(ion storage layer)/Li2O-B2O3(electrolyte layer)/tungsten trioxide (electrochromic layer)/indium tin oxide (transparent conductive layer)]The electrochromic device of (1) has a fade switching time of up to a dozen seconds to several minutes, and the fade switching speed is significantly reduced with an increase in the number of cycles, due to the electrolyte Li2O-B2O3Has a lithium ion conductivity of only 10-9S/cm and is significantly affected by trace moisture (Cogan SF, Rauh RD, Klein JD, Nguyen, Jones RB, Plant TD. variable transmittance coatings using electrochromism chloride and amophorus WO)3thin films. J. Flectrochem. Soc.,1997,144(3): 956-; wu et al [ glass (substrate)/indium tin oxide ] by magnetron sputtering(transparent conductive layer)/tungsten trioxide (electrochromic layer)/LiNbO3(electrolyte layer)/Nickel oxide (ion storage layer)/indium tin oxide (transparent conductive layer)]Structural electrochromic device, electrolyte LiNbO3Has an ion conductivity of 2 × 10-7S/cm, electron conductivity 2 × 10-11S/cm, the coloring process and the discoloring process of the device also take several tens of seconds (Wu Zhonghou, Diao Xungang, Dong Guobo.preparation and properties of all-solid-state inorganic thin film glass/ITO/WO)3/LiNbO3/NiOx/ITO electrochromic device.Proc.of SPIE Vol.9796979612-1)。
Disclosure of Invention
In view of the technical defects, the invention provides a solid electrolyte material of an all-solid-state electrochromic device. In addition, the present invention also provides a solid electrochromic window and a solid electrochromic mirror comprising the solid electrolyte material; and a method for manufacturing the solid electrochromic window and the solid electrochromic mirror.
The technical scheme for solving the technical problems is as follows:
a solid electrolyte material of an all-solid-state electrochromic device having the following chemical expression: lixSiyRezSmOnWherein x is more than or equal to 2 and less than or equal to 3, y is more than or equal to 0.5 and less than or equal to 2, z is more than or equal to 0.3 and less than or equal to 0.6, (x +4y +3z)/2.1 and more than or equal to m + n and less than or equal to (x +4y +3z)/1.8, and Re is selected from at least one of rare earth elements Y, Gd or Sm.
The lithium ion conductivity of the solid electrolyte material at room temperature is more than 7 × 10-5S/cm, electron conductivity less than 10-13S/cm, the electrochemical window is higher than 5.7V, and the catalyst can be stably used within the temperature range of-40 to 210 ℃.
The invention also provides an all-solid-state electrochromic device prepared by adopting the solid electrolyte material. The all-solid-state electrochromic device can be, for example, architectural gradient glass, automotive intelligent color-changing windows, aircraft portholes, color-changing sunglasses and automobile anti-chordal mesh rearview mirrors. In addition, the solid electrolyte material can be used for preparing electrochromic devices in the fields of information display, military technology and the like.
The invention also provides a solid electrochromic window which sequentially comprises a substrate, a first conducting layer, an electrochromic layer, an electrolyte layer, an ion storage layer and a second conducting layer; the electrolyte layer adopts the solid electrolyte material.
Preferably, in the solid electrochromic window, Re in the electrolyte layer is selected from rare earth elements Y or Sm.
In the solid electrochromic window, the first conducting layer and the second conducting layer are made of transparent conducting materials, preferably at least one of tin oxide, zinc oxide, indium tin oxide, indium gallium zinc oxide compound, fluorine-doped tin oxide, aluminum-doped zinc oxide and fluorine-doped zinc oxide.
In the solid electrochromic window, the electrochromic layer is formed by at least one of tungsten trioxide, dibismuth trioxide, molybdenum trioxide or nickel oxide.
In the solid electrochromic window, the ion storage layer is formed by at least one of lithium-embedded vanadium pentoxide, lithium-embedded titanium dioxide, lithium-embedded tungsten trioxide or lithium-embedded nickel oxide.
According to the preparation method of the solid electrochromic window, the first conducting layer, the electrochromic layer, the electrolyte layer, the ion storage layer and the second conducting layer are sequentially deposited on the surface of the substrate, or the first conducting layer, the electrochromic layer, the electrolyte layer, the ion storage layer and the second conducting layer are deposited in the opposite order.
The deposition method can select the conventional corresponding deposition method according to the material characteristics of each layer.
The preparation method of the solid electrochromic window specifically comprises the following steps:
step (1): depositing tin oxide, zinc oxide, indium tin oxide, indium gallium zinc oxide compound, fluorine-doped tin oxide, aluminum-doped zinc oxide or fluorine-doped zinc oxide on a substrate to form a first conductive layer; the thickness of the first conducting layer is 50-200 nm;
step (2): depositing tungsten trioxide, dibismuth trioxide, molybdenum trioxide or nickel oxide on the surface of the first conductive layer to form an electrochromic layer; the thickness of the electrochromic layer is 100-500 nm;
and (3): deposition of Li on the surface of electrochromic layersxSiyRezSmOnForming an electrolyte layer; the thickness of the electrolyte layer is 200-800 nm;
and (4): depositing lithium-embedded vanadium pentoxide, lithium-embedded titanium dioxide, lithium-embedded tungsten trioxide or lithium-embedded nickel oxide on the surface of the formed electrolyte layer to form an ion storage layer; the thickness of the ion storage layer is 100-500 nm;
and (5): depositing tin oxide, zinc oxide, indium tin oxide, indium gallium zinc oxide compound, fluorine-doped tin oxide, aluminum-doped zinc oxide or fluorine-doped zinc oxide on the surface of the formed ion storage layer to form a second conducting layer; the thickness of the second conductive layer is 50-200 nm.
The substrate may be a transparent organic polymer material or an inorganic material. Preferably, the substrate is glass.
The solid electrochromic window can be applied to the application fields of building glass, intelligent electrochromic windows for airplanes and vehicles, optical filters, decorative materials, stealth materials, color-changing sunglasses, information display and the like.
The invention also provides a solid electrochromic mirror which sequentially comprises a substrate, a conductive reflecting layer, a first conductive layer, an electrochromic layer, an electrolyte layer, an ion storage layer and a second conductive layer, wherein the electrolyte layer is selected from the solid electrolyte materials.
Preferably, in the solid electrochromic mirror, Re in the electrolyte layer is selected from rare earth elements Y or Sm.
In the solid electrochromic mirror, the first conducting layer and the second conducting layer are transparent and preferably consist of at least one of tin oxide, zinc oxide, indium tin oxide, indium gallium zinc oxide compound, fluorine-doped tin oxide, aluminum-doped zinc oxide and fluorine-doped zinc oxide.
In the solid electrochromic mirror, the conductive reflecting layer is made of noble metal and noble metal alloy.
Preferably, the conductive reflective layer is a silver layer, a platinum layer, or an alloy layer of silver and at least one of gold, chromium, ruthenium, platinum, rhodium, and palladium.
In the solid electrochromic mirror, the electrochromic layer is formed by at least one of tungsten oxide, bismuth trioxide, molybdenum trioxide or nickel oxide.
In the solid electrochromic mirror, the ion storage layer is formed by at least one of lithium-embedded vanadium pentoxide, lithium-embedded titanium dioxide, lithium-embedded tungsten trioxide or lithium-embedded nickel oxide.
The preparation method of the solid electrochromic mirror comprises the steps of sequentially depositing a first conducting layer, a conductive reflecting layer, an electrochromic layer, an electrolyte layer, an ion storage layer and a second conducting layer on the surface of a substrate; or the first conducting layer, the conductive reflecting layer, the ion storage layer, the electrolyte layer, the electrochromic layer and the second conducting layer are sequentially deposited on the substrate.
The deposition method can select the conventional corresponding deposition method according to the material characteristics of each layer.
The preparation method of the solid electrochromic mirror specifically comprises the following steps:
step (1): depositing silver, platinum, or an alloy of silver and at least one of gold, chromium, ruthenium, platinum, rhodium, palladium on a substrate to form a conductive reflective layer; the thickness of the conductive reflecting layer is 10-100 nm;
step (2): depositing tin oxide, zinc oxide, indium tin oxide, indium gallium zinc oxide compound, fluorine-doped tin oxide, aluminum-doped zinc oxide or fluorine-doped zinc oxide on the conductive reflecting layer to form a first conductive layer; the thickness of the first conductive layer is 50-200 nm;
and (3): depositing at least one of tungsten oxide, dibismuth trioxide, molybdenum trioxide or nickel oxide on the surface of the first conductive layer to form an electrochromic layer; the thickness of the electrochromic layer is 100-500 nm;
and (4): deposition of Li in electrochromic layersxSiyRezSmOnForming an electrolyte layer; the thickness of the electrolyte layer is 200-800 nm;
and (5): depositing lithium-embedded vanadium pentoxide, lithium-embedded titanium dioxide, lithium-embedded tungsten trioxide or lithium-embedded nickel oxide on the surface of the formed electrolyte layer to form an ion storage layer; the thickness of the ion storage layer is 100-500 nm;
and (6): depositing tin oxide, zinc oxide, indium tin oxide, indium gallium zinc oxide compound, fluorine-doped tin oxide, aluminum-doped zinc oxide or fluorine-doped zinc oxide on the surface of the formed ion storage layer to form a second conducting layer; the thickness of the second conducting layer is 50-200 nm.
In the solid electrochromic mirror, the substrate may be made of organic polymer material, glass, ceramic, metal, or the like. Preferably, the substrate is glass.
The solid electrochromic mirror can be applied to the application fields of automobile anti-chordal rearview mirrors and the like.
Compared with the prior art, the invention has the beneficial effects that:
the invention adopts LixSiyRezSmOn(x is more than or equal to 2 and less than or equal to 3, y is more than or equal to 0.5 and less than or equal to 2, z is more than or equal to 0.3 and less than or equal to 0.6, (x +4y +3z)/2.1 and more than or equal to m + n and less than or equal to (x +4y +3z)/1.8, and Re is selected from rare earth elements Y, Gd or Sm) as an electrolyte layer in the solid electrochromic device, and the electrolyte layer has high lithium ion conductivity, low electronic conductivity, wide electrochemical window and good temperature resistance, thereby obviously improving the fading rate and the cycle life of the solid electrochromic device. The transition response time between colored and faded states of the solid electrochromic window and solid electrochromic mirror of the present invention is less than 0.5 seconds. Alternately applying voltage (the forward voltage and the reverse voltage stay for 10 seconds respectively) to the electrochromic device to realize continuous conversion between the coloring state and the fading state, wherein after circulation is carried out for 10000 times, the difference between the visible light transmittance and the initial value of the solid electrochromic window in the coloring state is less than 4 percent, and the difference between the visible light transmittance and the initial value of the solid electrochromic window in the fading state is less than 3 percent; after 10000 times of circulation, the difference between the visible light reflectivity and the initial value of the solid electrochromic mirror in a colored state is less than 4%, and the difference between the visible light reflectivity and the initial value of the solid electrochromic mirror in a faded state is less than 4%, so that excellent stability is shown.