阅读说明：本技术 一种液相合成K2.25MgBe0.1Al0.1P0.05Ti0.05Si4.7O12钾快离子导体及其制备方法 (A kind of liquid phase synthesis K2.25MgBe0.1Al0.1P0.05Ti0.05Si4.7O12Potassium fast-ionic conductor and preparation method thereof ) 是由 水淼 舒杰 任元龙 于 2019-06-27 设计创作，主要内容包括：一种液相合成K_(2.25)MgBe_(0.1)Al_(0.1)P_(0.05)Ti_(0.05)Si_(4.7)O_(12)钾快离子导体及其制备方法,其特征为：常温钾离子电导率超过5·10~(-4)S/cm。采用Al~(3+)、Be~(2+)部分取代Si~(4+)离子,在晶体中产生间隙钾离子而降低钾离子迁移活化能；通过P~(5+)掺杂进一步降低快离子导体的电子导电性；通过小离子半径的Be~(2+)掺杂调节钾离子的迁移通道的大小以适应钾离子的快速迁移；通过Ti~(4+)部分掺杂形成畸变的晶格结构增加晶格缺陷有利于钾离子传导；并在制备过程中在K_2MgSi_5O_(12)颗粒的表面进行修饰,形成易烧结特性。这些协同作用使得该钾快离子导体的常温钾离子电导率超过5·10~(-4)S/cm,更加接近液态电解质的钾离子电导率。(A kind of liquid phase synthesis K 2.25 MgBe 0.1 Al 0.1 P 0.05 Ti 0.05 Si 4.7 O 12 Potassium fast-ionic conductor and preparation method thereof, it is characterized in that: room temperature potassium ion conductivity is more than 510 ‑4 S/cm.Using Al 3+ 、Be 2+ Part replaces Si 4+ Ion generates gap potassium ion in crystal and reduces potassium ion migration activation energy；Pass through P 5+ Doping further decreases the electron conduction of fast-ionic conductor；Pass through the Be of small ionic radii 2+ Doping adjusts the size of the migrating channels of potassium ion to adapt to the fast transferring of potassium ion；Pass through Ti 4+ The lattice structure that part doping forms distortion increases lattice defect and is conducive to potassium ions conduct；And during the preparation process in K 2 MgSi 5 O 12 The surface of particle is modified, and easy-sintering characteristic is formed.These synergistic effects are so that the room temperature potassium ion conductivity of the potassium fast-ionic conductor is more than 510 ‑4 S/cm is more nearly the potassium ion conductivity of liquid electrolyte.)

1. a kind of liquid phase synthesis K_2.25MgBe_0.1Al_0.1P_0.05Ti_0.05Si_4.7O₁₂Potassium fast-ionic conductor, it is characterized in that: room temperature potassium from Electron conductivity is more than 510^-4S/cm；Its preparation process is by solid KNO₃∶Al(NO₃)₃·9H₂O∶NH₄H₂PO₄∶Mg(NO₃)₂· 6H₂O is according to K_2.25MgBe_0.1Al_0.1P_0.05Ti_0.05Si_4.7O₁₂The ratio uniform of the nonstoichiometric molar ratio of middle respective element mixes, Intensively stirred while deionized water to all solid matter is added dissolves, the quality of deionized water be added is write down, Thereafter it continuously adds the deionized water of recorded 1.0-1.5 times of quality of deionized water quality and stirs evenly, continue to stir at this time It mixes and 35wt% beryllium nitrate aqueous solution amount of the substance of beryllium into solution system is added and meet K_2.25MgBe_0.1Al_0.1P_0.05Ti_0.05 Si_4.7O₁₂Stoichiometric ratio, and be added substance amount be 1.5-2.5 times of all metal ions total amount tartaric acid be sufficiently stirred Uniformly to being completely dissolved；Remember that this solution is solution A；K will be met_2.25MgBe_0.1Al_0.1P_0.05Ti_0.05Si_4.7O₁₂Stoichiometric ratio It is 1.0-1.5 times of the sum of tetraethyl orthosilicate and butyl titanate volume that tetraethyl orthosilicate and butyl titanate, which are dissolved in volume, Dehydrated alcohol in, remember this solution be solution B；Then solution A is added dropwise in solution B to whole under stiring and is added, and The temperature of solution system is risen to 40-50 DEG C afterwards and keep this temperature and stirring under conditions of with 3-5 drop/minute speed after It is continuous that deionized water is added, until solution gradually becomes sticky and is formed gelatin；By gelatin substance in 130-200 DEG C of baking oven It is ground 10-30 minutes in mortar after 20-48 hours dry；Powder after grinding is in air atmosphere with 5-30 DEG C/min Rate is warming up to furnace cooling after 550-650 DEG C of heat preservation 3-10 hours；Powder after cooling is ground in alms bowl in agate and is regrind 10-30 minutes, the powder after grinding was warming up to 1250- in platinum crucible in air atmosphere with 5-15 DEG C/min of rate 1350 DEG C are taken out burner hearth after heat preservation 25-48 hours and cooled down rapidly；By the hydroxide after substance after cooling grinding in 0.1-0.3M It filters, dry and in a press 1 × 10 after being impregnated 5-15 minutes in sodium solution⁷Pa-8×10⁷The pressure of Pa depresses to thin The porcelain boat is put into tube furnace 10-60Pa's by piece by half SiO 2 powder full of porcelain boat of thin slice obtained embedment This is made in furnace cooling after rate in oxygen atmosphere with 5-10 DEG C/min is warming up to 750-850 DEG C of heat preservation 80-150 hours Potassium fast-ionic conductor.

Technical field

The present invention relates to a kind of solid potassium fast-ionic conductor manufacturing fields.

Background technique

Lithium ion battery has volume, weight energy than high, voltage is high, self-discharge rate is low, memory-less effect, cycle life The absolute advantages such as length, power density height possess in global mobile power source market and exceed 30,000,000,000 dollar/year shares and far more than other The occupation rate of market of battery is electrochmical power source [Wu Yuping, Wan Chunrong, Jiang Changyin, the lithium ion two of most market development prospect Primary cell, Beijing: Chemical Industry Press, 2002.].Lithium ion secondary battery is most of using liquid both at home and abroad at present Electrolyte, liquid lithium ionic cell have some unfavorable factors, and such as: liquid organic electrolyte may be revealed, in excessively high temperature Lower generation explosion can not apply the occasion high in some pairs of security requirements to cause safety accident；Liquid electrolyte lithium from The sub- generally existing Capacity fading problem of battery, after a period of use due to electrode active material in the electrolyte molten Solution, reaction and degradation failure [Z.R.Zhang, Z.L.Gong, and Y.Yang, J.Phys.Chem.B, 108,2004, 17546.].And all-solid-state battery it is highly-safe, substantially without Capacity fading, wherein fast as the solid that electrolyte uses Ion conductor also acts the effect of diaphragm, simplifies the structure of battery；Further, since also simplifying life without completely cutting off air To the requirement of equipment during production, the configuration design of battery is also more convenient and flexible, and [Wen Zhaoyin, Zhu Xiujian know hero etc., entirely perhaps The research of solid secondary batteries, the 12nd Chinese solid-state ionics academic meeting paper collection, 2004.].

In all-solid lithium-ion battery, migration rate of the carrier in fast-ionic conductor is often far smaller than electrode surface Electric charge transfer and ion diffusion rates in positive electrode and become the rate determining step in entire electrode reaction dynamics, Therefore it is the core key for constructing high performance lithium ion battery that developing, which has the inorganic fast ionic conductor of higher li ionic conductivity, Place.From the point of view of current lithium fast-ionic conductor Development Status: LLTO (Li, La) TiO₃Fast-ionic conductor has very high transgranular Conductivity is (10^-3S/cm or so) and relatively high room temperature total conductivity (10^-4S/cm-10^-5S/cm), but LLTO decomposes electricity It forces down, the above all-solid-state battery of discharge voltage 3.7V and unstable to lithium anode can not be constituted；It is more with NASICON type Brilliant LiM₂(PO₄)₃(M=Ti, Ge, Zr) is by tetrahedron PO₄With octahedra MO₆The grid structure collectively constituted, generation finish Hole and fillable coordination on structure, allow to regulate and control a large amount of Li ion, are a kind of up-and-coming high-lithium ion electricity Conductance fast-ionic conductor.By the substitution of aliovalent ion, introduce hole in the structure or calking lithium ion can further improve from Subconductivity [Xiaoxiong Xu, Zhaoyin Wen, ZhonghuaGu, et al., Solid State Ionics, 171, 2004,207-212.].Such as woods ancestral Zuxiang, Li Shichun [woods ancestral Zuxiang, Li Shichun, silicate journal, 9 (3), 1981,253-257.] It was found that Li_1+xTi_2-xGa_xP₃O₁₂, Li_1+2xTi_2-xMgxP₃O₁₂, Li_1+xGe_2-xCrxP₃0₁₂, Li_1+xGe_2-xAl_xP₃O₁₂, Li_{1+ x}Ti_2-xIn_xP₃O₁₂Etc. systems or other such as Li_1+2x+2yAl_xMg_yTi_2-x-ySi_xP_3-xO₁₂, Li_1+x+yAl_xTi_2-xSi_yP_3-yO₁₂, Li_{1+ x}Al_xTi_2-xP₃O₁₂Etc. systems all have higher lithium ion conductivity.But the room temperature lithium ion conductivity of these systems usually exists 10^-4S/cm-10^-6Between S/cm, requirement of the non-film lithium ion battery to electrolytic conductivity can't be met very well.In addition NASICON system is equally unstable to lithium anode.Ramaswamy Murugan is equal to 2007 in German application term A kind of novel lithium ion fast-ionic conductor Li has been reported on periodical₇La₃Zr₂O₁₂Its lithium ion conductivity at normal temperature is more than 1 × 10^-4S·cm^-1, decomposition voltage is more than 5.5V, and lithium metal can be used as cathode, be that one kind has very much to air and moisture stabilization The fast ion solid electrolyte of the lithium of application potential (Ramaswamy Murugan, Venkataraman Thangadurai, Werner Weppner, (2007) " Fast lithium ion conduction in garnet-type Li₇La₃Zr₂O₁₂" Angewandte Chemie-International Edition 46 (41): 7778-7781.).However 5.0 × 10 will often be reached to the higher occasion conductivity of current requirements^-4S/cm or so just can satisfy normal battery operation It needs, in addition the solid electrolyte synthesis temperature is at 1350 DEG C or so, and temperature is high, and energy consumption is high.

It additionally needs and is pointed out that the consumption of lithium rises rapidly as secondary cell is quickly applied in power battery, Reserves of the elemental lithium in the earth's crust very it is low only PPM grade, rare lithium resource make future lithium ion battery cost it is continuous on It rises.The electrochemical energy storing device for seeking a kind of alternative low cost becomes urgent problem to be solved.Sodium and potassium element are in the earth The electrochemical properties very high and with lithium of abundance have certain similar, be following to be expected to replace most having for lithium ion all-solid-state battery uncommon The selection of prestige.However the building essential potassium ion conductor of potassium ion all-solid-state battery is also substantially at space state at present. Therefore screening has the potassium fast ion conducting material of high conductance to the inexpensive kalium ion battery of building and full-solid potassium ion Battery has great importance.

Summary of the invention

A kind of liquid phase synthesis K that the technical problem to be solved by the present invention is to provide for existing background technique_2.25Mg Be_0.1Al_0.1P_0.05Ti_0.05Si_4.7O₁₂Potassium fast-ionic conductor and preparation method thereof.Using Al³⁺、Be²⁺Part replaces Si⁴⁺Ion, In crystal generate high concentration gap potassium ion, thus generate short distance more potassium ions collaboration migration, facilitate reduce potassium from Son migration activation energy；Pass through P⁵⁺Doping further decreases the electron conduction of fast-ionic conductor；Pass through the Be of small ionic radii²⁺ Doping adjusts the size of the migrating channels of potassium ion to adapt to the fast transferring of potassium ion；Pass through Ti⁴⁺Part doping forms distortion Lattice structure increase lattice defect be conducive to potassium ions conduct；And during the preparation process in K₂MgSi₅O₁₂The surface of particle into Row modification, forms easy-sintering characteristic, is conducive to improve the potassium fast-ionic conductor and reduces crystal boundary gap, increasing when preparing bulk devices Add consistency to improve the potassium ion conductivity of block potassium fast-ionic conductor.These synergistic effects are so that the potassium fast-ionic conductor Room temperature potassium ion conductivity be more than 510^-4S/cm is more nearly the potassium ion conductivity of liquid electrolyte.

The present invention reaches by the following technical solutions, which provides a kind of room temperature potassium ion conductivity and be more than 5·10^-4The potassium fast-ionic conductor of S/cm, stoichiometric equation K_2.25MgBe_0.1Al_0.1P_0.05Ti_0.05Si_4.7O₁₂。

In the technical scheme, by solid KNO₃∶Al(NO₃)₃·9H₂O∶NH₄H₂PO₄∶Mg(NO₃)₂·6H₂O is according to K_2.25 MgBe_0.1Al_0.1P_0.05Ti_0.05Si_4.7O₁₂The ratio uniform of the nonstoichiometric molar ratio of middle respective element mixes, and is stirring strongly While deionized water to all solid matter be added dissolve, write down the quality of deionized water be added, continue thereafter plus Enter the deionized water of recorded 1.0-1.5 times of quality of deionized water quality and stirs evenly, continue to stir at this time and be added 35wt% beryllium nitrate aqueous solution amount of the substance of beryllium into solution system meets K_2.25MgBe_0.1Al_0.1P_0.05Ti_0.05Si_4.7O₁₂'s Stoichiometric ratio, and the amount of substance is added and stirs for the tartaric acid of 1.5-2.5 times of all metal ions total amount to complete Fully dissolved；Remember that this solution is solution A；K will be met_2.25MgBe_0.1Al_0.1P_0.05Ti_0.05Si_4.7O₁₂The positive silicic acid four of stoichiometric ratio Ethyl ester and butyl titanate are dissolved in the anhydrous second that volume is 1.0-1.5 times of the sum of tetraethyl orthosilicate and butyl titanate volume In alcohol, remember that this solution is solution B；Then solution A is added dropwise in solution B to all adding, then by solution under stiring The temperature of system is risen to 40-50 DEG C and keeps being continuously added under conditions of this temperature and stirring with 3-5 drop/minute speed Ionized water, until solution gradually becomes sticky and formed gelatin.Gelatin substance is dried into 20- in 130-200 DEG C of baking oven It is ground 10-30 minutes in mortar after 48 hours；Powder after grinding is heated up in air atmosphere with 5-30 DEG C/min of rate To 550-650 DEG C of furnace cooling after heat preservation 3-10 hours；Powder after cooling is ground into 10-30 points of regrinding in alms bowl in agate Clock, rate of the powder in air atmosphere in platinum crucible with 5-15 DEG C/min after grinding are warming up to 1250-1350 DEG C of heat preservation Burner hearth is taken out after 25-48 hours to cool down rapidly；It will be soaked in the sodium hydroxide solution of 0.1-0.3M after substance after cooling grinding Bubble is filtered after 5-15 minutes, is dried and in a press 1 × 10⁷Pa-8×10⁷The pressure of Pa pushes flakiness, will be obtained In half SiO 2 powder full of porcelain boat of thin slice embedment, which is put into tube furnace in the oxygen atmosphere of 10-60Pa Furnace cooling after being warming up to 750-850 DEG C of heat preservation 80-150 hours with 5-10 DEG C/min of rate；The fast ion of the potassium ion is made Conductor sheet.If Fig. 1 is that group becomes K_2.25MgBe_0.1Al_0.1P_0.05Ti_0.05Si_4.7O₁₂The XRD spectrum of potassium fast-ionic conductor, spectrum Line meets PDF card 82-0548 K₂MgSi₅O₁₂It is 7.810 through LCR821 impedance analyzer measurement conductivity mutually without miscellaneous phase^{- 4}S/cm。

Compared with the prior art, the advantages of the present invention are as follows: use Al³⁺、Be²⁺Part replaces Si⁴⁺Ion, in crystal High concentration gap potassium ion is generated, to generate more potassium ions collaboration migration of short distance, helping, which reduces potassium ion migration, lives Change energy；Pass through P⁵⁺Doping further decreases the electron conduction of fast-ionic conductor；Pass through the Be of small ionic radii²⁺Doping is adjusted The size of the migrating channels of potassium ion is to adapt to the fast transferring of potassium ion；Pass through Ti⁴⁺Part doping forms the lattice knot of distortion Structure increases lattice defect and is conducive to potassium ions conduct；It will be particularly beneficial that during the preparation process in K₂MgSi₅O₁₂The surface of particle Modified, form easy-sintering characteristic, be conducive to improve the potassium fast-ionic conductor reduced when preparing bulk devices crystal boundary gap, Increase consistency to improve the potassium ion conductivity of block potassium fast-ionic conductor.These synergistic effects are so that the fast ion of the potassium is led The room temperature potassium ion conductivity of body is more than 510^-4S/cm is very beneficial for the building of full-solid potassium ion battery.

Detailed description of the invention

Fig. 1 is that group becomes K_2.25MgBe_0.1Al_0.1P_0.05Ti_0.05Si_4.7O₁₂The XRD spectrum of potassium fast-ionic conductor.

Specific embodiment

Below in conjunction with embodiment, present invention is further described in detail.