阅读说明：本技术 一种液相合成K6.25Be0.1Al0.1P0.05Ti0.05Si1.7O7钾快离子导体及其制备方法 (A kind of liquid phase synthesis K6.25Be0.1Al0.1P0.05Ti0.05Si1.7O7Potassium 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_(6.25)Be_(0.1)Al_(0.1)P_(0.05)Ti_(0.05)Si_(1.7)O_7钾快离子导体及其制备方法,其特征为：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_6Si_2O_7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~-~4S/cm,更加接近液态电解质的钾离子电导率。(A kind of liquid phase synthesis K 6.25 Be 0.1 Al 0.1 P 0.05 Ti 0.05 Si 1.7 O 7 Potassium fast-ionic conductor and preparation method thereof, it is characterized in that: use 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 6 Si 2 O 7 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_6.25Be_0.1Al_0.1P_0.05Ti_0.05Si_1.7O₇Potassium fast-ionic conductor, it is characterized in that: room temperature potassium ion electricity Conductance is more than 510^-4S/cm；Its preparation process is by solid KNO₃∶Al(NO₃)₃·9H₂O∶NH₄H₂PO₄According to K_6.25Be_0.1 Al_0.1P_0.05Ti_0.05Si_1.7O₇The ratio uniform of the nonstoichiometric molar ratio of middle respective element mixes, and adds simultaneously intensively stirred Enter deionized water to all solid matters to dissolve, writes down the quality of deionized water be added, continuously add recorded thereafter 1.0-1.5 times of quality of deionized water quality deionized water and stir evenly, continue to stir and be added 35wt% nitric acid at this time Beryllium aqueous solution amount of the substance of beryllium into solution system meets K_6.25Be_0.1Al_0.1P_0.05Ti_0.05Si_1.7O₇Stoichiometric ratio, and The amount that substance is added is that the tartaric acid of 1.5-2.5 times of all metal ions total amount is stirred to being completely dissolved；Remember that this is molten Liquid is solution A；K will be met_6.25Be_0.1Al_0.1P_0.05Ti_0.05Si_1.7O₇Four fourth of tetraethyl orthosilicate and metatitanic acid of stoichiometric ratio Ester is dissolved in the dehydrated alcohol that volume is 1.0-1.5 times of the sum of tetraethyl orthosilicate and butyl titanate volume, remembers this solution For solution B；Then solution A is added dropwise in solution B to all adding under stiring, then rises the temperature of solution system Deionized water is continuously added to 40-50 DEG C and under conditions of keeping this temperature and stirring with 3-5 drop/minute speed, until solution Gradually become sticky and is formed gelatin；In mortar after gelatin substance is dried 20-48 hours in 130-200 DEG C of baking oven Middle grinding 10-30 minutes；Rate of the powder in air atmosphere with 5-30 DEG C/min after grinding is warming up to 400-500 DEG C of guarantor Furnace cooling after 3-10 hours warm；Powder after cooling is ground in alms bowl in agate and is regrind 10-30 minutes, the powder after grinding Rate in air atmosphere with 5-15 DEG C/min is warming up to furnace cooling after 600-700 DEG C of heat preservation 10-20 hours；Taking-up is ground It filters, dry and in a press 1 × 10 after being impregnated 5-15 minutes in the sodium hydroxide solution of 0.1-0.3M after mill⁷Pa-8 ×10⁷The pressure of Pa pushes flakiness, and thin slice obtained is put into tube furnace in the oxygen atmosphere of 10-60Pa with 5-10 DEG C/min rate be warming up to 700-850 DEG C of heat preservation 20-45 hours after furnace cooling the potassium fast-ionic conductor is made.

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_6.25 Be_0.1Al_0.1P_0.05Ti_0.05Si_1.7O₇Potassium fast-ionic conductor and preparation method thereof.Using Al³⁺、Be²⁺Part replaces Si⁴⁺Ion, In High concentration gap potassium ion is generated in crystal, to generate more potassium ions collaboration migration of short distance, helps to reduce potassium ion Migrate activation energy；Pass through P⁵⁺Doping further decreases the electron conduction of fast-ionic conductor；Pass through the Be of small ionic radii²⁺It mixes The size of the miscellaneous migrating channels for adjusting potassium ion is to adapt to the fast transferring of potassium ion；Pass through Ti⁴⁺Part doping forms distortion Lattice structure increases lattice defect and is conducive to potassium ions conduct；And during the preparation process in K₆Si₂O₇It is repaired on the surface of particle Decorations form easy-sintering characteristic, are conducive to improve the potassium fast-ionic conductor and reduce crystal boundary gap when preparing bulk devices, increase cause Density is to improve the potassium ion conductivity of block potassium fast-ionic conductor.These act synergistically so that the potassium fast-ionic conductor it is normal Warm potassium ion conductivity is 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_6.25Be_0.1Al_0.1P_0.05Ti_0.05Si_1.7O₇。

In the technical scheme, by solid KNO₃∶Al(NO₃)₃·9H₂O∶NH₄H₂PO₄According to K_6.25Be_0.1Al_0.1P_0.05 Ti_0.05Si_1.7O₇The ratio uniform of the nonstoichiometric molar ratio of middle respective element mixes, intensively stirred while deionization is added Water to all solid matters dissolve, and write down the quality of deionized water be added, continuously add recorded deionization thereafter The deionized water of 1.0-1.5 times of quality of water quality simultaneously stirs evenly, and continues to stir and be added 35wt% beryllium nitrate aqueous solution at this time Into solution system, the amount of the substance of beryllium meets K_6.25Be_0.1Al_0.1P_0.05Ti_0.05Si_1.7O₇Stoichiometric ratio, and substance is added Amount be that the tartaric acid of 1.5-2.5 times of all metal ions total amount is stirred to being completely dissolved；Remember that this solution is solution A；K will be met_6.25Be_0.1Al_0.1P_0.05Ti_0.05Si_1.7O₇The tetraethyl orthosilicate and butyl titanate of stoichiometric ratio are dissolved in Volume is to remember that this solution is solution B in the dehydrated alcohol of 1.0-1.5 times of the sum of tetraethyl orthosilicate and butyl titanate volume； Then solution A is added dropwise in solution B to all adding under stiring, the temperature of solution system is then risen into 40-50 DEG C and keep with 3-5 drop/minute speed continuously adding deionized water under conditions of this temperature and stirring, until solution gradually becomes It is sticky and formed gelatin.Gelatin substance is ground in mortar after drying 20-48 hours in 130-200 DEG C of baking oven 10-30 minutes；Rate of the powder in air atmosphere with 5-30 DEG C/min after grinding is warming up to 400-500 DEG C of heat preservation 3-10 Furnace cooling after hour；Powder after cooling is ground in alms bowl in agate and is regrind 10-30 minutes, the powder after grinding is in air Rate in atmosphere with 5-15 DEG C/min is warming up to furnace cooling after 600-700 DEG C of heat preservation 10-20 hours；Take out grinding after It filters, dry and in a press 1 × 10 after being impregnated 5-15 minutes in the sodium hydroxide solution of 0.1-0.3M⁷Pa-8×10⁷Pa Pressure push flakiness, thin slice obtained is put into tube furnace in the oxygen atmosphere of 10-60Pa with 5-10 DEG C/min Rate is warming up to furnace cooling after 700-850 DEG C of heat preservation 20-45 hours；The potassium ion fast-ionic conductor thin slice is made.As Fig. 1 is K_6.25Be_0.1Al_0.1P_0.05Ti_0.05Si_1.7O₇The XRD spectrum of potassium fast-ionic conductor, spectral line meet PDF card 72-1518 K₆Si₂O₇It is 6.210 through LCR821 impedance analyzer measurement conductivity mutually without miscellaneous phase^-4S/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；Also not it is beneficial that during the preparation process in K₆Si₂O₇The surface of particle carries out Modification forms easy-sintering characteristic, is conducive to improve the potassium fast-ionic conductor and reduces crystal boundary gap, increase when preparing bulk devices Consistency is to improve the potassium ion conductivity of block potassium fast-ionic conductor.These act synergistically so that the potassium fast-ionic conductor Room temperature potassium ion conductivity 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 K_6.25Be_0.1Al_0.1P_0.05Ti_0.05Si_1.7O₇The XRD spectrum of potassium fast-ionic conductor.

Specific embodiment

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