Bimetal-doped high ion conduction ceramic solid electrolyte

Abstract

The invention discloses a bimetal doped high ion conduction ceramic solid electrolyte, which comprises an LATP solid electrolyte formed by an NASICON type lithium ion conductor of Li1. 3AL0. 3Ti1. 7 (PO4) 3, and Ti < 4 + > in the LATP solid electrolyte is replaced by metal ions. The invention belongs to the technical field of solid-state batteries, and particularly relates to a bimetallic-doped high-ion-conduction ceramic solid-state electrolyte.

Description

Technical Field

[0001] The present invention belongs to the technical field of solid-state batteries, and in particular relates to a bimetal-doped high-ion-conducting ceramic solid electrolyte. Background Art

[0002] Solid-state lithium batteries are of great significance in the future of energy storage and electric vehicles. Compared with traditional liquid electrolyte lithium-ion batteries, solid-state batteries have higher energy density, longer service life and better safety performance. They are less likely to burn or explode and can withstand higher temperatures, which makes them particularly suitable for use in electric vehicles. In addition, solid-state batteries charge faster and may significantly reduce charging time. The development of this technology is expected to promote the popularization of electric vehicles and reduce dependence on fossil fuels, thus making an important contribution to addressing climate change and achieving sustainable development goals. However, to achieve large-scale commercialization of solid-state lithium batteries, some technical challenges still need to be overcome, such as improving ionic conductivity and solving interface stability problems.

[0003] As the most critical component of solid-state batteries, SSE S Generally, they can be divided into two categories: inorganic solid electrolytes and solid polymer electrolytes. Inorganic electrolytes include ceramic Li 10 G 2 S 12 、Na 3 Zr 2 Si 2 PO 12 , Li 3 InCl 6 and Li 7 La 3 Zr 2 O 12 , with high ionic conductivity, mechanical strength and thermal stability. However, ceramic electrolytes have poor ion conductivity, poor interface contact due to their brittleness and rigidity, which limits their application in solid-state batteries. Summary of the invention

[0004] The technical problem to be solved by the present invention is the existing equipment.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: a high ion conductivity ceramic solid electrolyte doped with double metals, comprising Li 1.3 AL 0.3 Ti 1.7 (PO 4 ) 3 The LATP solid electrolyte consists of NASICON-type lithium-ion conductors.

[0006] Furthermore, the Ti in the LATP solid electrolyte4+ by metal ion replacement.

[0007] Furthermore, the metal ions are bimetallic elements.

[0008] Further, the metal ion replacement

[0009] Developing metal-doped Li instead of Ti 1.3 AL 0.3 (Ti 1.7-y M y )(PO 4 ) 3 The sol-gel synthesis method, wherein y=0.3 and M=M n and S n .

[0010] Furthermore, the specific experimental process of the sol-gel synthesis method is as follows:

[0011] 1) Mix the precursor containing concentric nitric acid and distilled water in a volume ratio of 1:4 and add Mn(NO 3 ) 2 +SnCl 2 and Ti(C 6 H 9 O) 4 A mixed solution is formed. The stoichiometric amount of LiNO 3 and Al(NO 3 ) 3 9H 2 O was dissolved in the aqueous solution and stirred at 50 °C for about 1 hour to form a stable and clear solution;

[0012] 2) Use NH 3 ·H 2 The mixed solution was adjusted to pH = 5 and NH 4 H 2 (PO) 4 and citric acid, wherein the molar ratio of citric acid to total metal ions is set to 4:1;

[0013] 3) After being kept at 90°C for about 5 hours, the mixed solution becomes a homogeneous latex solution, which is then transferred to a heating device and heated at 120°C until a xerogel is produced to promote esterification between ethylene glycol and citric acid;

[0014] 4) The obtained dry gel was heated to 250°C in a high temperature furnace for 2 hours to promote pyrolysis. Finally, it was calcined in air at 850°C for 5 hours while increasing the temperature at 5°C min-1;

[0015] 5) ball milling with a planetary ball mill using a 1 mm diameter Zr ball (the ratio of Zr ball to LATP powder is 1:15) at 700 rpm for 90 min to obtain highly refined Mn / Sn-doped LATP powder;

[0016] 6) Dry the powder at 120° C. for 2 hours. The final Mn / Sn doped LATP powders were designated as LATP, Mn-LATP-L, Sn-LATP-M and MnSn-LATP according to the different metal types, based on the x value of the Mn / Sn elements being 0.3 respectively.

[0017] After adopting the above structure, the beneficial effects of the present invention are as follows:

[0018] Li 1.3 AL 0.3 (Ti 1.7-y M y )(LATP) is a NASICON type lithium ion conductor. LATP is characterized by high chemical stability in air, low cost, low toxicity, electrochemical stability, easy synthesis, and high ionic conductivity. The ionic conductivity at room temperature is as high as 1.0×10 -4 Scm-1. Through part of Al 3+ Replacement Ti 4+ Due to charge compensation, the extra lithium ions in the crystal partially occupy the active sites, promoting the mobility of lithium ions in the crystal. In addition, LATP has a high Young's modulus, which can reduce the impedance of the interface. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0020] Figure 1 A schematic diagram of the crystal structure of the bimetallic doped LATP ceramic powder proposed in the present invention;

[0021] Figure 2 This is a schematic diagram of a specific experiment of the sol-gel synthesis method proposed in the present invention;

[0022] Figure 3 A schematic diagram of the crystal structure of the LATP ceramic powder proposed in the present invention;

[0023] Figure 4 This is a schematic diagram of the conductive data proposed by the present invention. DETAILED DESCRIPTION

[0024] like Figure 1 As shown, the bimetallic doped high ion conductivity ceramic solid electrolyte comprises Li 1.3 AL0.3 Ti 1.7 (PO 4 ) 3 LATP solid electrolyte composed of NASICON type lithium ion conductor, Ti in LATP solid electrolyte 4+ by metal ion replacement.

[0025] Among them, the metal ions are bimetallic elements, and metal-doped Li is developed by replacing Ti with metal ions. 1.3 AL 0.3 (Ti 1.7-y M y )(PO 4 ) 3 Sol-gel synthesis method, y = 0.3 and M = M n and S n .

[0026] Among them, Figure 2 The specific experimental process of the sol-gel synthesis method is as follows:

[0027] 1) Mix the precursor containing concentric nitric acid and distilled water in a volume ratio of 1:4 and add Mn(NO 3 ) 2 +SnCl 2 and Ti(C 6 H 9 O) 4 A mixed solution is formed. The stoichiometric amount of LiNO 3 and Al(NO 3 ) 3 9H 2 O was dissolved in the aqueous solution and stirred at 50 °C for about 1 hour to form a stable and clear solution;

[0028] 2) Use NH 3 ·H 2 The mixed solution was adjusted to pH = 5 and NH 4 H 2 (PO) 4 and citric acid, wherein the molar ratio of citric acid to total metal ions is set to 4:1;

[0029] 3) After being kept at 90°C for about 5 hours, the mixed solution becomes a homogeneous latex solution, which is then transferred to a heating device and heated at 120°C until a xerogel is produced to promote esterification between ethylene glycol and citric acid;

[0030] 4) The obtained dry gel was heated to 250°C in a high temperature furnace for 2 hours to promote pyrolysis. Finally, it was calcined in air at 850°C for 5 hours while increasing the temperature at 5°C min-1;

[0031] 5) ball milling with a planetary ball mill using a 1 mm diameter Zr ball (the ratio of Zr ball to LATP powder is 1:15) at 700 rpm for 90 min to obtain highly refined Mn / Sn-doped LATP powder;

[0032] 6) Dry the powder at 120° C. for 2 hours. The final Mn / Sn doped LATP powders were designated as LATP, Mn-LATP-L, Sn-LATP-M and MnSn-LATP according to the different metal types, based on the x value of the Mn / Sn elements being 0.3 respectively.

[0033] like Figure 3-4 As shown, when used specifically, Li 1.3 AL 0.3 Ti 1.7 (PO 4 ) 3 (LATP) is a NASICON type lithium ion conductor. The characteristics of LATP are high chemical stability in air, low cost, low toxicity, electrochemical stability, easy synthesis, and high ionic conductivity. The ionic conductivity of LATP at room temperature is as high as 1.0×10 -4 Scm -1 . Through part Al 3+ Replacement Ti 4+ Due to charge compensation, the extra lithium ions in the crystal partially occupy the active sites, promoting the mobility of lithium ions in the crystal. In addition, LATP has a high Young's modulus, which can reduce the impedance of the interface.

[0034] At present, the methods for preparing LATP electrolyte mainly include solid phase reaction, coprecipitation, melt quenching, hydrothermal method and sol-gel method. Solid phase reaction is the most suitable method for large-scale production due to its simple preparation process. LATP electrolyte is prepared by sintering at a temperature above 950°C to maximize its ionic conductivity. In addition, the addition of sintering agents can reduce the sintering temperature and increase the density of LATP electrolyte. Sintering aids usually have a low melting point and transform into a liquid phase during the sintering process below 900°C, promoting the contact between LATP particles and increasing its compactness at low temperatures. At present, LATP is widely used in the research of LIB. With the development of SSE, LATP will be expected to be practically developed in all-solid-state lithium batteries.

[0035] In the field of solid-state batteries, solid electrolytes are important components, usually inorganic electrolytes represented by ceramics and solid polymer electrolytes. A large number of studies have shown that ceramic materials such as perovskites, garnets, sodium superionic conductors (NASICONs) and amorphous oxides are mature and promising candidates for SSEs in lithium-ion batteries. Among the various candidate materials, ceramic ion conductors with NASICON structures show great promise as solid-state materials for energy storage devices. A noteworthy configuration is LATP (Li 1 +xAl x Ti 2 -x(PO 4 ) 3 ), where x = 0.3, has attracted attention for its potential to enhance lithium ion conductivity. The attraction of LATP lies in its ability to crystallize in a rhombohedral lattice, which allows the PO 4 Tetrahedron and TiO 6 The shared corners between the octahedra form Li + Therefore, LATP is considered to be a superionic conductor, with ionic conductivity reported to be in the range of 10 -4 Scm -1 calcined in air for 5 hours at 5℃min -1 Warming up.

[0036] Although the embodiments of the present invention have been shown and described, it is understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents. In general, if those skilled in the art are inspired by them and design structural methods and embodiments similar to the technical solution without creativity without departing from the purpose of the present invention, they shall all fall within the scope of protection of the present invention.

Claims

1. A bimetallic doped high ion conductivity ceramic solid electrolyte, characterized in that: Including by Li 1.3 AL 0.3 Ti 1.7 The LATP solid electrolyte is composed of a NASICON-type lithium ion conductor of (PO4)3, which consists of Li 1.3 AL 0.3 Ti 1.7 LATP solid electrolyte composed of NASICON-type lithium ion conductor of (PO4)3.

2. The bimetallic doped high ion conductivity ceramic solid electrolyte according to claim 1, characterized in that: The metal ions are bimetallic elements.

3. The bimetallic doped high ion conductivity ceramic solid electrolyte according to claim 1, characterized in that: The metal-doped Li 1.3 AL 0.3 (Ti 1.7-y M y )(PO4)3 sol-gel synthesis method, wherein y=0.3 and M=M n and S n .

4. The bimetallic doped high ion conductivity ceramic solid electrolyte according to claim 3, characterized in that: The specific experimental process of the sol-gel synthesis method is as follows: 1) The precursor containing concentric nitric acid and distilled water were mixed thoroughly in a volume ratio of 1:4 and Mn(NO3)2+SnCl2 and Ti(C6H9O)4 were added to form a mixed solution. Stoichiometric amounts of LiNO3 and Al(NO3)3·9H2O were dissolved in the aqueous solution and stirred at 50°C for about 1 hour to form a stable and clear solution; 2) adjusting the mixed solution to pH=5 using NH3·H2O, and gradually adding NH4H2(PO)4 and citric acid, wherein the molar ratio of citric acid to total metal ions is set to 4:1; 3) After being kept at 90°C for about 5 hours, the mixed solution becomes a homogeneous latex solution, which is then transferred to a heating device and heated at 120°C until a dry gel is produced to promote esterification between ethylene glycol and citric acid; 4) The obtained dry gel was heated to 250°C in a high temperature furnace for 2 hours to promote pyrolysis. Finally, it was calcined in air at 850°C for 5 hours while increasing the temperature at 5°C min-1; 5) ball milling with a planetary ball mill using a 1 mm diameter Zr ball (the ratio of Zr ball to LATP powder is 1:15) at 700 rpm for 90 min to obtain highly refined Mn / Sn-doped LATP powder; 6) Dry the powder at 120° C. for 2 hours. The final Mn / Sn doped LATP powders were designated as LATP, Mn-LATP-L, Sn-LATP-M and MnSn-LATP according to the different metal types, based on the x value of the Mn / Sn elements being 0.3 respectively.

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