CN110336008A - A kind of P5+、Al3+、Be2+、Zn2+The K of ion collaboration doping6Si2O7Potassium fast-ionic conductor and preparation method thereof - Google Patents

Abstract

A kind of P⁵⁺、Al³⁺、Be²⁺、Zn²⁺The K of ion collaboration doping₆Si₂O₇Potassium fast-ionic conductor and preparation method thereof, it is characterized in that: stoichiometric equation K_{6+2x+y‑z‑2m}Be_xAl_yP_z Zn_mSi_{2‑x‑y‑z}O₇, in which: x=0.1-0.2；Y=0.1-0.2；Z=0.02-0.05；M=0.02-0.05；Room temperature potassium ion conductivity is more than 510^‑4S/cm.Using Al³⁺、Be²⁺Part replaces Si⁴⁺Ion generates gap potassium ion in crystal and reduces potassium ion migration activation energy；Pass through P⁵⁺Doping further decreases the electron conduction of fast-ionic conductor: by 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 Zn²⁺Part replaces potassium ion that cation vacancy is caused to increase potassium ion migrating channels；And during the preparation process in K₆Si₂O₇The 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.

Description

A kind of P5+、Al3+、Be2+、Zn2+The K of ion collaboration doping6Si2O7Potassium fast-ionic conductor And preparation method thereof

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 P that the technical problem to be solved by the present invention is to provide for existing background technique⁵⁺、Al³⁺、Be²⁺、Zn²⁺ The K of ion collaboration doping₆Si₂O₇Potassium fast-ionic conductor and preparation method thereof.Using Al³⁺、Be²⁺Part replaces Si⁴⁺Ion, in crystalline substance High concentration gap potassium ion is generated in body, to generate more potassium ions collaboration migration of short distance, helping, which reduces potassium ion, is moved Move activation energy；Pass through P⁵⁺Doping further decreases the electron conduction of fast-ionic conductor；Pass through the Be of small ionic radii²⁺Doping The size of the migrating channels of potassium ion is adjusted to adapt to the fast transferring of potassium ion；Pass through Zn²⁺Part replaces potassium ion to cause sun Ionic vacancies increase potassium ion migrating channels；And during the preparation process in K₆Si₂O₇The surface of particle is modified, and is formed and is easily burnt Junction characteristic is conducive to improve the potassium fast-ionic conductor and reduces crystal boundary gap when preparing bulk devices, increases consistency to mention The potassium ion conductivity of high block potassium fast-ionic conductor.These act synergistically so that the room temperature potassium ion of the potassium fast-ionic conductor is electric Conductance 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+2x+y-z-2mBe_xAl_yP_z Zn_mSi_2-x-y-zO₇, in which: x= 0.1-0.2；Y=0.1-0.2；Z=0.02-0.05；M=0.02-0.05.

In the technical scheme, by K₂CO₃∶NH₄H₂PO₄∶Al₂O₃∶SiO₂: BeO: ZnO according to K_{6+2x+y-z- 2m}Be_xAl_yP_zZn_mSi_2-x-y-zO₇Nonstoichiometric molar ratio ratio uniform mixing, additions quality be mixture quality 3%-9% Dehydrated alcohol, in the ball mill with revolving speed ball milling 10-50 hours of 200-500 revs/min, at 60 DEG C -120 after ball milling It is 2-10 hour dry in DEG C vacuum drying oven (gas pressure is in 3Pa-20Pa in baking oven), it is re-grind in agate stone roller alms bowl after taking-up 10-30 minutes, rate of the powder in air atmosphere with 5-30 DEG C/min after grinding was warming up to 450-550 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 650-750 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 750-950 DEG C of heat preservation 20-48 hours；The potassium ion fast-ionic conductor thin slice is made.As Fig. 1 is Group becomes K_6.24Be_0.1Al_0.1P_0.02Zn_0.02Si_1.78O₇The XRD spectrum of potassium fast-ionic conductor, spectral line meet PDF card 72- 1518K₆Si₂O₇It is 7.010 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 Zn²⁺Part replaces potassium ion to cause cation Vacancy increases potassium ion migrating channels；More beneficial is during the preparation process in K₆Si₂O₇The surface of particle is modified, shape At easy-sintering characteristic, is conducive to improve the potassium fast-ionic conductor and reduces crystal boundary gap when preparing bulk devices, increase consistency 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 Ionic 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 that group becomes K_6.24Be_0.1Al_0.1P_0.02Zn_0.02Si_1.78O₇The XRD spectrum of potassium fast-ionic conductor.

Specific embodiment

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

Embodiment 1: by K₂CO₃∶NH₄H₂PO₄∶Al₂O₃∶SiO₂: BeO: ZnO according to K_6.24Be_0.1Al_0.1P_0.02Zn_0.02Si_{1.7 8}O₇Nonstoichiometric molar ratio ratio uniform mixing be added quality be mixture quality 3% dehydrated alcohol, in the ball mill With revolving speed ball milling 11 hours of 200 revs/min, after ball milling in 60 DEG C of vacuum drying ovens (gas pressure is in 3Pa in baking oven) It is 3 hours dry, it grinds in alms bowl and re-grinds 12 minutes in agate after taking-up, the powder after grinding is in air atmosphere with 5 DEG C/min Rate be warming up to 450 DEG C heat preservation 3 hours after furnace cooling；Powder after cooling is ground in agate and regrinds 10 points in alms bowl Clock, furnace cooling after the powder after grinding is warming up to 660 DEG C of heat preservations 10 hours in air atmosphere with 6 DEG C/min of rate；It takes It is impregnated in the sodium hydroxide solution of 0.1M after grinding out and filters, dries and in a press 1.2 × 10 after five minutes⁷Pa's Pressure pushes flakiness, and thin slice obtained is put into tube furnace and is heated up in the oxygen atmosphere of 12Pa with 5 DEG C/min of rate Furnace cooling after keeping the temperature 20 hours to 760 DEG C；The potassium ion fast-ionic conductor thin slice is made.

Embodiment 2: by K₂CO₃∶NH₄H₂PO₄∶Al₂O₃∶SiO₂: BeO: ZnO according to K_6.45Be_0.2Al_0.2P_0.05Zn_0.05Si_{1.5 5}O₇Nonstoichiometric molar ratio ratio uniform mixing, be added quality be mixture quality 8% dehydrated alcohol, in the ball mill With revolving speed ball milling 45 hours of 400 revs/min, at 110 DEG C of vacuum drying ovens after ball milling (gas pressure is in 20Pa in baking oven) Middle drying 10 hours, after taking-up agate grind alms bowl in re-grind 30 minutes, the powder after grinding in air atmosphere with 30 DEG C/ The rate of minute is warming up to furnace cooling after 550 DEG C of heat preservations 10 hours；Powder after cooling is ground in alms bowl in agate and is regrind 28 minutes, the powder after grinding was cold with furnace after being warming up to 750 DEG C of heat preservations 20 hours with 15 DEG C/min of rate in air atmosphere But；Take out filtering after impregnating 15 minutes after grinding in the sodium hydroxide solution of 0.3M, dry and in a press 7 × 10⁷The pressure of Pa pushes flakiness, and thin slice obtained is put into tube furnace in the oxygen atmosphere of 60Pa with 10 DEG C/min Rate is warming up to furnace cooling after 850 DEG C of heat preservations 45 hours；The potassium ion fast-ionic conductor thin slice is made.

Embodiment 3: by K₂CO₃∶NH₄H₂PO₄∶Al₂O₃∶SiO₂: BeO: ZnO according to K_6.36Be_0.15Al_0.15P_0.03Zn_0.03 Si_1.67O₇Nonstoichiometric molar ratio ratio uniform mixing, be added quality be mixture quality 5% dehydrated alcohol, in ball milling With revolving speed ball milling 40 hours of 300 revs/min in machine, in 90 DEG C of vacuum drying ovens, (gas pressure exists in baking oven after ball milling Dry 8 hours in 18Pa), grind in alms bowl and re-grind 20 minutes in agate after taking-up, the powder after grinding in air atmosphere with 25 DEG C/min of rate is warming up to furnace cooling after 500 DEG C of heat preservations 7 hours；Powder after cooling is ground in alms bowl again in agate Grinding 20 minutes, powder after grinding be warming up to 700 DEG C of heat preservations 15 hours in air atmosphere with 10 DEG C/min of rate after with Furnace is cooling；Take out impregnated in the sodium hydroxide solution of 0.2M after grinding filter after ten minutes, dry and in a press 5 × 10⁷The pressure of Pa pushes flakiness, and thin slice obtained is put into tube furnace in the oxygen atmosphere of 30Pa with 7 DEG C/min Rate is warming up to furnace cooling after 800 DEG C of heat preservations 30 hours；The potassium ion fast-ionic conductor thin slice is made.

Embodiment 4: by K₂CO₃∶NH₄H₂PO₄∶Al₂O₃∶SiO₂: BeO: ZnO according to K_6.29Be_0.1Al_0.15P_0.02Zn_0.02 Si_1.73O₇Nonstoichiometric molar ratio ratio uniform mixing, be added quality be mixture quality 3% dehydrated alcohol, in ball milling With revolving speed ball milling 20 hours of 200 revs/min in machine, in 70 DEG C of vacuum drying ovens, (gas pressure exists in baking oven after ball milling It is 2 hours dry in 5Pa), it grinds in alms bowl and re-grinds 10 minutes in agate after taking-up, the powder after grinding is in air atmosphere with 5 DEG C/min rate be warming up to 460 DEG C heat preservation 5 hours after furnace cooling；Powder after cooling is ground in alms bowl in agate and is ground again Mill 10 minutes, the powder after grinding are warming up to after 700 DEG C of heat preservations 10 hours with 5 DEG C/min of rate with furnace in air atmosphere It is cooling；Take out filtering after impregnating 6 minutes after grinding in the sodium hydroxide solution of 0.1M, dry and in a press 3 × 10⁷The pressure of Pa pushes flakiness, and thin slice obtained is put into tube furnace in the oxygen atmosphere of 50Pa with 5 DEG C/min Rate is warming up to furnace cooling after 780 DEG C of heat preservations 25 hours；The potassium ion fast-ionic conductor thin slice is made.

Embodiment 5: by K₂CO₃∶NH₄H₂PO₄∶Al₂O₃∶SiO₂: BeO: ZnO according to K_6.31Be_0.15Al_0.1P_0.03Zn_0.03 Si_1.72O₇Nonstoichiometric molar ratio ratio uniform mixing, be added quality be mixture quality 3% dehydrated alcohol, in ball milling With revolving speed ball milling 12 hours of 200 revs/min in machine, in 120 DEG C of vacuum drying ovens, (gas pressure exists in baking oven after ball milling It is 2 hours dry in 20Pa), it grinds in alms bowl and re-grinds 10 minutes in agate after taking-up, the powder after grinding is in air atmosphere with 5 DEG C/min rate be warming up to 450 DEG C heat preservation 3 hours after furnace cooling；Powder after cooling is ground in alms bowl in agate and is ground again Mill 20 minutes, the powder after grinding are warming up to after 700 DEG C of heat preservations 10 hours with 10 DEG C/min of rate with furnace in air atmosphere It is cooling；Take out impregnated in the sodium hydroxide solution of 0.3M after grinding filter after ten minutes, dry and in a press 5 × 10⁷The pressure of Pa pushes flakiness, and thin slice obtained is put into tube furnace in the oxygen atmosphere of 50Pa with 7 DEG C/min Rate is warming up to furnace cooling after 830 DEG C of heat preservations 32 hours；The potassium ion fast-ionic conductor thin slice is made.

Claims (1)

1. a kind of P⁵⁺、Al³⁺、Be²⁺、Zn²⁺The K of ion collaboration doping₆Si₂O₇Potassium fast-ionic conductor, it is characterized in that: stoichiometric equation For K_6+2x+y-z-2mBe_xAl_yP_zZn_mSi_2-x-y-zO₇, in which: x=0.1-0.2；Y=0.1-0.2；Z=0.02-0.05；M=0.02- 0.05；Room temperature potassium ion conductivity is more than 510^-4S/cm；Its preparation process is by K₂CO₃∶NH₄H₂PO₄∶Al₂O₃∶SiO₂∶BeO : ZnO is according to K_6+2x+y-z-2mBe_xAl_yP_zZn_mSi_2-x-y-zO₇Nonstoichiometric molar ratio ratio uniform mixing, be added quality be mixed The dehydrated alcohol of amount of substance 3%-9% is closed, in the ball mill with revolving speed ball milling 10-50 hours of 200-500 revs/min, ball milling After in gas pressure be 3Pa-20Pa, temperature be it is 2-10 hours dry in 60 DEG C of -120 DEG C of vacuum drying ovens, in Ma after taking-up Nao, which is ground in alms bowl, to be re-grind 10-30 minutes, and the powder after grinding is warming up in air atmosphere with 5-30 DEG C/min of rate 450-550 DEG C of furnace cooling after heat preservation 3-10 hours；Powder after cooling is ground in alms bowl in agate and is regrind 10-30 minutes, Rate of the powder in air atmosphere with 5-15 DEG C/min after grinding is warming up to after 650-750 DEG C of heat preservation 10-20 hours with furnace It is cooling；Take out grinding after is impregnated 5-15 minute in the sodium hydroxide solution of 0.1-0.3M after filter, dry and in a press 1 × 10⁷Pa-8×10⁷The pressure of Pa pushes flakiness, and thin slice obtained is put into the oxygen gas in tube furnace in 10-60Pa The fast ion of the potassium is made in furnace cooling after rate in atmosphere with 5-10 DEG C/min is warming up to 750-950 DEG C of heat preservation 20-48 hours Conductor.