CN103066272B

CN103066272B - Ni2+,Mn4+,Si4+,Zn2+,F-The lithium-rich anode material of doping surfaces modification and preparation method

Info

Publication number: CN103066272B
Application number: CN201310022225.2A
Authority: CN
Inventors: 杨天赐; 水淼; 舒杰; 程亮亮; 冯琳; 任元龙; 郑卫东; 高珊
Original assignee: Ningbo University
Current assignee: Ningbo University
Priority date: 2013-01-05
Filing date: 2013-01-05
Publication date: 2016-05-18
Anticipated expiration: 2033-01-05
Also published as: CN103066272A

Abstract

A kind of Ni²⁺，Mn⁴⁺，Si⁴⁺，Zn²⁺，F^-The Na5icon solid electrolyte LiTi of doping₂(PO₄)₃Layer-layer composite lithium-rich anode material of surface modification, the stoichiometric equation of its surface reforming layer is Li_1+2x+m+z-yZn_x(Mn_0.5Ni_0.5)_mSi_zTi_2-x_-mP_3-zO_12-yF_y, wherein: x=0.1-0.5; Y=0.1-0.2; M=0.1-0.3; Z=0.1-0.3; The stoichiometric equation of layer-layer composite lithium-rich anode material is xLi₂MnO₃.(1-x)LiMn_0.5Ni_0.5O₂(0≤x≤0.5); The amount of substance of surface reforming layer is the 1%-10% of positive electrode amount. The positive electrode of this surface modification has high circulation volume hold facility and outstanding multiplying power property.

Description

Ni2+,Mn4+,Si4+,Zn2+,F-The lithium-rich anode material of doping surfaces modification and preparation method

Technical field

The present invention relates to a kind of anode material for lithium-ion batteries and manufacture field.

Background technology

Lithium ion battery have volume, weight energy than high, voltage is high, self-discharge rate is low, memory-less effect, have extended cycle life, the high absolute advantage of power density, have the occupation rate of market that exceedes 30,000,000,000 dollars of/year shares and far exceed other batteries in global portable power source market, the electrochmical power source [Wu Yuping most with future develop, Wan Chunrong, Jiang Changyin, lithium rechargeable battery, Beijing: Chemical Industry Press, 2002.]. But since lithium ion battery commercialization in 1991, the actual specific capacity of positive electrode is hovered all the time between 100-180mAh/g, the low bottleneck that promotes lithium ion battery specific energy that become of positive electrode specific capacity. If want effectively to improve the energy density of lithium ion battery, must be from the viewpoint of improving the voltage difference between positive and negative pole material and developing two of height ratio capacity electrode materials.

The current commercial lithium ion battery the most widely positive electrode of practicality is LiCoO₂, the theoretical specific capacity of cobalt acid lithium is 274mAh/g, and actual specific capacity is between 130-140mAh/g, and cobalt is strategic materials, expensive and have larger toxicity. Therefore in recent years, the researcher of countries in the world is devoted to the research and development of Olivine-type Cathode Material in Li-ion Batteries always, up till now, the lithium ion cell positive filtering out reaches tens of kinds, but really has potential commercial applications prospect or appeared at positive electrode on market very few really. As lithium manganate having spinel structure LiMn₂O₄, its cost is lower, and than being easier to preparation, security performance is also relatively good, but capacity is lower, and theoretical capacity is 148mAh/g, and actual capacity is at 100-120mAh/g, and this material capacity circulation hold facility is not good, and under high temperature, capacity attenuation is very fast, Mn³⁺John-Teller effect and the dissolving in electrolyte perplexing for a long time researcher. The LiNiO of layer structure₂And LiMnO₂Although there is larger theoretical specific capacity, be respectively 275mAh/g and 285mAh/g, their preparations are very difficult, poor heat stability, cyclicity is very poor, and capacity attenuation is very fast. And business-like LiFePO4 LiFePO progressively at present₄Cost is low, Heat stability is good, environmental friendliness, but its theoretical capacity approximately only has 170mAh/g, and actual capacity is in 140mAh/g left and right.

In recent years, researcher gradually by high lithium than on positive electrode, particularly the high lithium of manganese base manganese-nickel binary and manganese base manganese-nickel-cobalt ternary solid solution system compares positive electrode, these materials have very high Capacity Ratio, high stability and relative cheap cost and are subject to people's concern [Young-SikHong, YongJoonPark, etal., SolidStateIonics, 2005,176:1035～1042]. Rich lithium material can be regarded the continuous solid solution xLi of Li2MnO3 and LiM ' O2 (M '=Mn, Co, Ni, Mn05Ni05 etc.) as₂MnO₃.(1-x)LiM′O₂. As M '=Mn_0.5Ni_0.5Time, be xLi₂MnO₃.(1-x)LiMn_0.5Ni_0.5O₂The rich lithium composite positive pole of layer-layer. Li₂MnO₃Have halite structure, symmetry is C2/m. Can be write as Li[Li_1/3Mn_2/3]O₂Form is the layer structure of Li layer and manganese layer formation, Li⁺And Mn⁴⁺Common formation manganese layer, each octahedra Li+ is by six octahedra Mn⁴⁺The formation Li (Mn) that surrounds₆Structure, and lithium ion in Li layer is tetrahedral structure. Li₂MnO₃Electro-chemical activity lower, electronic conductivity and ionic conductivity are also very little. As itself and the LiMn that is all layer structure_0.5Ni_0.5O₂After compound, form the rich lithium layered cathode material xLi of layered-layered structure₂MnO₃.(1-x)LiMn_0.5Ni_0.5O₂, make the positive electrode of this structure have the discharge capacity that exceedes 200mAh/g. This material is in the time that charging voltage is less than 4.6V, and Mn keeps+4 valencys constant, Li₂MnO₃Structure keeps inertia, and the stability of positive electrode structure is provided, and prevents that material structure caves in charge and discharge process, and Ni, from+become+4 valencys of divalent state, is the active component of generation capacity. In the time that charging voltage exceedes 4.6V, will there will be a platform in 4.6V position, this is Li₂O is from Li₂MnO₃In lattice, deviate from completely and become MnO₂, more than at this moment cell voltage will reach 4.8V; In the time that battery starts to discharge, the Li previously having deviate from₂O does not return in lattice, along with the Ni that carries out of electric discharge⁴⁺Be reduced to gradually Ni²⁺, the Mn in material subsequently⁴⁺Also be reduced participation electrochemical process, therefore Li₂MnO₃Activation while exceeding 4.6V is that this material has the reason [Johnson, C.S., N.Li, etal., Electrochemistrycommunications, 2007,9 (4): 787-795.] that exceedes 200mAh/g.

But, in fact xLi₂MnO₃.(1-x)LiM′O₂The microstructure of the rich lithium layered cathode material of layered-layered structure is very complicated, as ThackerayM.M.[ThackerayMM, KangS-H, JohnsonCS, etal.JournalofMaterialsChemistry, 2007,17:3112-3125.] etc. people point out like that, the result of study of XRD and x ray absorption near edge structure test all shows xLi₂MnO₃.(1-x)LiMn_0.5Ni_0.5O₂O₂The rich lithium layered cathode material of layered-layered structure is not pure solid solution, and excessive lithium ion is distributed in transition metal layer by arest neighbors Mn⁴⁺Surround, form the LiMn of local cluster₆Structure, and LiMn₆Li just₂MnO₃Feature structure. Therefore xLi₂MnO₃.(1-x)LiMn_0.5Ni_0.5O₂Material structure is regarded stratiform Li as₂MnO₃With stratiform LiMn_0.5Ni_0.5O₂Compound on nanoscale, its lithium ion and the arranging shortrange order of transition metal ions and long-range is unordered more suitable. Like this, due to insulation phase Li₂MnO₃Existence, Li₂MnO₃The electronic conductivity of feature structure and ionic conductivity are all very low, on the other hand, and xLi₂MnO₃.(1-x)LiMn_0.5Ni_0.5O₂Laminate Li₂MnO₃Interlamellar spacing and LiMn_0.5Ni_0.5O₂It is larger that interlamellar spacing differs, and both coupling causes the embedding of lithium ion and deviate from more difficultly, causes the overall lithium ion conductivity of composite low, and lithium ion diffusion coefficient is 10^-12-10^-13S/cm²Between. So xLi₂MnO₃.(1-x)LiMn_0.5Ni_0.5O₂Cyclical stability not good, repeatedly circulation after capacity attenuation very fast, in the time that charging and discharging currents increases, capacity attenuation is very fast.

Finishing is a kind of very effective method of improving rich lithium stratiform anode material for compound lithium ion battery cyclical stability and multiplying power property, such as sour pretreatment can be xLi₂MnO₃.(1-x)LiMn_0.5Ni_0.5O₂In structure, LiO composition filters out in advance, thereby makes the efficiency for charge-discharge of circulation in first week bring up to more than 90% [KangSH, ThackerayMM., ElectrochemicalSociety, 2008,155:A269-A275.]. Some oxides are as Al₂O₃，ZrO₂，ZnO，CeO₂[MyungST, IzumiK, KomabaS, etal.J.Phys.Chem.C, 2007,111 (10): 4061-4067] the coated Surface Oxygen activity that can be reduced in rich lithium stratiform anode material for compound lithium ion battery under high voltage in surface, isolated electrode material and electrolyte to a certain extent, slow down the destruction that discharges effects on surface lattice structure due to HF, thereby improve its cyclic discharge capacity hold facility. But current finishing component only plays the effect of guard electrode surface of active material structure conventionally; more limited to improving its multiplying power property effect; and; because the variation of volume can periodically occur electrode material in cyclic process; therefore between electrode material and clad, after long-term circulation, unavoidably can produce break-off, cause losing the effect of clad. Therefore further explore the finishing of this positive electrode to developing the high performance xLi of composite lithium-rich anode material layer by layer₂MnO₃.(1-X)LiMn_0.5Ni_0.5O₂There is very important meaning.

Summary of the invention

Technical problem to be solved by this invention is a kind of Ni providing for existing background technology²⁺，Mn⁴⁺，Si⁴⁺，Zn²⁺，F^-The Nasicon solid electrolyte LiTi of doping₂(PO₄)₃Layer-layer composite lithium-rich anode material xLi of surface modification₂MnO₃.(1-x)LiMn_0.5Ni_0.5O₂(0≤x≤0.5)。Ni2+，Mn⁴⁺，Si⁴⁺，Zn²⁺，F^-Doping increases substantially the electrical conductivity of Nasicon solid electrolyte; Zn²⁺Part substitutes Ti⁴⁺, mole Zn of unit²⁺Can produce 2mol calking lithium ion, avoid introducing a large amount of at a low price octahedral structures that ions bring and distorted and make up because the adulterate gap lithium ion quantity that causes of F-reduces. Si⁴⁺Part replaces and F^-Part substitutes P⁵⁺Interstitial ion quantity is further increased; And F^-Part has substituted the oxonium ion in Ti-O octahedron, has following effect: (1) F-is the extremely strong anion of electronegativity, and part replaces O^2-The rear stability that increases structure, has reduced Li-O bond energy, has weakened lithium ion and skeleton bonding force, has strengthened Li⁺Transfer ability; (2) F^-Ionic radius is less than O^2-, therefore can reduce the steric hindrance that in one group of Li (II) room-Li (II) Void diffusing, oxonium ion causes; (3) reduced the transmission bottleneck that anion forms, made more to mate with Li+ size. As be coated to-layer of this solid electrolyte composite lithium-rich anode material xLi₂MnO₃.(1-x)LiMn_0.5Ni_0.5O₂When (0≤x≤0.5) is upper, be reduced on the one hand the Surface Oxygen activity of rich lithium stratiform anode material for compound lithium ion battery under high voltage, reduced positive electrode has reduced HF release effects on surface lattice structure destruction with contacting of electrolyte; On the other hand, due to Ni²⁺，Mn⁴⁺，Si⁴⁺，Zn²⁺，F^-The Nasicon solid electrolyte LiTi of doping₂(PO₄)₃Be the solid electrolyte of high-lithium ion electrical conductivity, normal temperature ionic conductivity is up to 10^-4More than S/cm, therefore improve the low shortcoming of positive electrode lithium ion conductivity, simultaneously Ni²⁺，Mn⁴⁺With (Mn_0.5Ni_0.5) version doping, the solid-state electrolyte layer of modified layer is made up of similar nickel manganese to electrode material, both physics, the mismatch of chemical property are reduced, reduce clad the coming off on positive electrode of causing due to circulation Volume Changes, these factors make layer-layer composite lithium-rich anode material xLi₂MnO₃.(1-x)LiMn_0.5Ni_0.5O₂(0≤x≤0.5) has better circulation volume hold facility and multiplying power property.

The present invention reaches by the following technical solutions, and this technical scheme provides the Ni of a kind of high circulation volume hold facility and multiplying power property²⁺，Mn⁴⁺，Si⁴⁺，Zn²⁺，F^-The Nasicon solid electrolyte LiTi of doping₂(PO₄)₃Layer-layer composite lithium-rich anode material of surface modification, the stoichiometric equation of its surface reforming layer is Li_1+2x+m+z-yZn_x(Mn_0.5Ni_0..5)_mSi_zTi_2-x-mP_3-zO_12-yF_y, wherein: x=0.1-0.5; Y=0.1-0.2; M=0.1-0.3; Z=0.1-0.3; The stoichiometric equation of layer-layer composite lithium-rich anode material is xLi₂MnO₃.(1-x)LiMn_0.5Ni_0.5O₂(0≤x≤0.5); The amount of substance of surface coating layer is the 1%-10% of positive electrode material amount.

In this technical scheme, will be according to stoichiometric equation xLi₂MnO₃.(1-x)LiMn_0.5Ni_0.5O₂The soluble lithium compounds of (0≤x≤0.5), soluble manganese salt, soluble nickel salt are dissolved in deionized water, and adding amount of substance is that all metal ions total amount 1.2-2.0 tartaric acid doubly stirs to dissolving completely; By the temperature rise of system, to 70-85 DEG C of lasting stirring until the water of 70-85% evaporates, at this moment solution becomes gradually thickness and forms gelatin. Gelatin material is ground to 10-30 minute after dry 20-48 hour in the baking oven of 130-200 DEG C in mortar. The powder obtaining is warmed up to 500-600 DEG C and at this temperature lower calcination 3-5 hour with the speed of 2-10 DEG C/min in tube furnace, cooling rear taking-up powder, in mortar, continue to grind 10-30 minute, powder is pressed into sheet with the pressure of 100-300MPa, in tube furnace, be warmed up to 850-950 DEG C of calcining 5-15 hour with the speed of 2-10 DEG C/min, obtain lithium-rich anode material after cooling with stove. Will be according to stoichiometric equation Li_1+2x+m+z-yZn_x(Mn_0.5Ni_0.5)_mSi_zTi_2-x-mP_3-zO_12-yF_y, wherein: x=0.1-0.5; Y=0.1-0.2; M=0.1-0.3; Z=0.1-0.3; Soluble lithium compounds, soluble zinc salt, soluble nickel salt, soluble manganese salt, butyl titanate, tetraethyl orthosilicate, ammonium dihydrogen phosphate (ADP), LiF join in deionized water at normal temperature and continue and stir, increase the temperature to 50-70 DEG C, adding amount of substance is that citric acid doubly of all metal ions amount 2.5-3.5 vigorous stirring are until solution becomes clear; Add the lithium-rich anode material powder that 10-100 doubly measures to form suspension, continuing under the condition stirring, the temperature of rising suspension is to 75-85 DEG C, slow evaporation moisture, until system becomes the muddy of thickness, this material is put into take out after 100-160 DEG C of oven drying 10-20 hour be warmed up to 450-550 DEG C of calcining with the speed of 2-10 DEG C/min and after 5-10 hour, continue to be warmed up to 850-950 DEG C of calcining 10-20 hour with the speed of 2-10 DEG C/min, with the cooling Ni that obtains of stove²⁺，Si⁴⁺，Zn²⁺，F^-The Nasicon solid electrolyte LiTi of doping₂(PO₄)₃Layer-layer composite lithium-rich anode material of surface modification. Wherein: solubility lithium salts is LiNO₃、CH₃One in COOLi; Soluble manganese salt is Mn (CH₃COO)₂·4H₂O、MnSO₄·H₂One in O; Soluble nickel salt is Ni (CH₃COO)₂·4H₂O、NiSO₄·6H₂One in O; Soluble zinc salt is ZnSO₄·7H₂O、Zn(NO₃)₂·6H₂One in O. Fig. 1 is charging capacity, discharge capacity and the efficiency for charge-discharge figure of front 20 circulations of this richness lithium material.

Compared with prior art, the invention has the advantages that: as be coated to-layer of this solid electrolyte composite lithium-rich anode material xLi₂MnO₃.(1-x)LiMn_0.5Ni_0.5O₂When (0≤x≤0.5) is upper, be reduced on the one hand the Surface Oxygen activity of rich lithium stratiform anode material for compound lithium ion battery under high voltage, reduced positive electrode has reduced HF release effects on surface lattice structure destruction with contacting of electrolyte; On the other hand, due to Ni²⁺，Mn⁴⁺，Si⁴⁺，Zn²⁺，F^-The Nasicon solid electrolyte LiTi of doping₂(PO₄)₃Be the solid electrolyte of high-lithium ion electrical conductivity, normal temperature ionic conductivity is up to 10^-4More than S/cm, therefore improve the low shortcoming of positive electrode lithium ion conductivity, simultaneously Ni²⁺，Mn⁴⁺With (Mn_0.5Ni_0.5) version doping, the solid-state electrolyte layer of modified layer is made up of similar nickel manganese compound to electrode material, both physics, the mismatch of chemical property are reduced, reduce clad the coming off on positive electrode of causing due to circulation Volume Changes, these factors make layer-layer composite lithium-rich anode material xLi₂MnO₃.(1-x)LiMn_0.5Ni_0.5O₂(0≤x≤0.5) has better circulation volume hold facility and multiplying power property.

Brief description of the drawings

Charging capacity, discharge capacity and the efficiency for charge-discharge figure of front 20 circulations of this richness lithium material of Fig. 1.

Detailed description of the invention

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

Embodiment 1: by LiNO₃∶Mn(CH₃COO)₂·4H₂O∶Ni(CH₃COO)₂·4H₂O=1.1: the ratio of 0.55: 0.45 (mol ratio) is evenly mixed, is dissolved in deionized water, and adding amount of substance is that the tartaric acid of 1.2 times of all metal ions total amounts stirs to dissolving completely; The temperature rise to 70 of system DEG C is continued to stir until 71% water evaporates, and at this moment solution becomes gradually thickness and forms gelatin. Gelatin material is ground 10 minutes after dry 22 hours in the baking oven of 130 DEG C in mortar. The powder obtaining is warmed up to 500 DEG C and this temperature lower calcination 3 hours with the speed of 2 DEG C/min in tube furnace, cooling rear taking-up powder, in mortar, continue to grind 10 minutes, powder is pressed into sheet with the pressure of 100MPa, then in tube furnace, be warmed up to 850 DEG C of calcinings 5 hours with the speed of 2 DEG C/min, obtain this lithium-rich anode material after cooling with stove. By LiNO₃、ZnSO₄·7H₂O、Ni(CH₃COO)₂·4H₂O、Mn(CH₃COO)₂·4H₂O, butyl titanate, tetraethyl orthosilicate, ammonium dihydrogen phosphate (ADP), LiF amount of substance ratio are=1.2: 0.1: 0.05: 0.05: 1.8: 0.1: 2.9: 0.1 joins in deionized water at normal temperature, its total amount of substance is lithium-rich anode material 2%, continue to stir rising system temperature to 50 DEG C, adding amount of substance is that the citric acid of 2.6 times of all metal ions amounts vigorous stirring are until solution becomes clear; Above-mentioned lithium-rich anode material powder is joined in clear liquid and forms suspension, continuing under the condition stirring, the temperature to 75 DEG C of rising suspension, slow evaporation moisture, until system becomes the muddy of thickness, by this material put into 120 DEG C of oven dryings after 10 hours, take out with the speed of 2 DEG C/min be warmed up to 450 DEG C calcining 5 hours after continue with the speed of 2 DEG C/min be warmed up to 850 DEG C calcining 10 hours, with the cooling Ni that obtains of stove²⁺，Mn⁴⁺，Si⁴⁺，Zn²⁺，F^-The Nasicon solid electrolyte LiTi of doping₂(PO₄)₃Layer-layer composite lithium-rich anode material of surface modification.

Embodiment 2:: by LiNO₃∶Mn(CH₃COO)₂·4H₂O∶Ni(CH₃COO)₂·4H₂O=1.5: the ratio of 0.75: 0.25 (mol ratio) is evenly mixed, is dissolved in deionized water, and adding amount of substance is that the tartaric acid of 1.6 times of all metal ions total amounts stirs to dissolving completely; The temperature rise to 80 of system DEG C is continued to stir until 75% water evaporates, and at this moment solution becomes gradually thickness and forms gelatin. Gelatin material is ground 20 minutes after dry 40 hours in the baking oven of 150 DEG C in mortar. The powder obtaining is warmed up to 550 DEG C and this temperature lower calcination 4 hours with the speed of 5 DEG C/min in tube furnace, cooling rear taking-up powder, in mortar, continue to grind 20 minutes, powder is pressed into sheet with the pressure of 200MPa, then in tube furnace, be warmed up to 900 DEG C of calcinings 5 hours with the speed of 5 DEG C/min, obtain this lithium-rich anode material after cooling with stove. By LiNO₃、ZnSO₄·7H₂O、Ni(CH₃COO)₂·4H₂O、Mn(CH₃COO)₂·4H₂O, butyl titanate, tetraethyl orthosilicate, ammonium dihydrogen phosphate (ADP), LiF amount of substance ratio are=1.7: 0.3: O.1: 0.1: 1.5: 0.2: join at 2.8: 0.15 in deionized water at normal temperature, its total amount of substance is lithium-rich anode material 5%, continue to stir rising system temperature to 50 DEG C, adding amount of substance is that the citric acid of 2.6 times of all metal ions amounts vigorous stirring are until solution becomes clear; Above-mentioned lithium-rich anode material powder is joined in clear liquid and forms suspension, continuing under the condition stirring, the temperature to 75 DEG C of rising suspension, slow evaporation moisture, until system becomes the muddy of thickness, by this material put into 140 DEG C of oven dryings after 15 hours, take out with the speed of 6 DEG C/min be warmed up to 500 DEG C calcining 8 hours after continue with the speed of 6 DEG C/min be warmed up to 900 DEG C calcining 15 hours, with the cooling Ni that obtains of stove²⁺，Mn⁴⁺，Si⁴⁺，Zn²⁺，F^-The Nasicon solid electrolyte LiTi of doping₂(PO₄)₃Layer-layer composite lithium-rich anode material of surface modification.

Embodiment 3: by LiNO₃∶Mn(CH₃COO)₂·4H₂O∶Ni(CH₃COO)₂·4H₂O=1.2: the ratio of 0.6: 0.4 (mol ratio) is evenly mixed, is dissolved in deionized water, and adding amount of substance is that the tartaric acid of 2.0 times of all metal ions total amounts stirs to dissolving completely; The temperature rise to 85 of system DEG C is continued to stir until 83% water evaporates, and at this moment solution becomes gradually thickness and forms gelatin. Gelatin material is ground 30 minutes after dry 48 hours in the baking oven of 200 DEG C in mortar. The powder obtaining is warmed up to 600 DEG C and this temperature lower calcination 5 hours with the speed of 10 DEG C/min in tube furnace, cooling rear taking-up powder, in mortar, continue to grind 30 minutes, powder is pressed into sheet with the pressure of 300MPa, then in tube furnace, be warmed up to 950 DEG C of calcinings 15 hours with the speed of 9 DEG C/min, obtain this lithium-rich anode material after cooling with stove. By LiNO₃、ZnSO₄·7H₂O、Ni(CH₃COO)₂·4H₂O、Mn(CH₃COO)₂·4H₂O, butyl titanate, tetraethyl orthosilicate, ammonium dihydrogen phosphate (ADP), LiF amount of substance ratio are=2.2: 0.5: 0.15: 0.15: 1.2: 0.3: 2.7: 0.2 joins in deionized water at normal temperature, its total amount of substance is lithium-rich anode material 9%, continue to stir rising system temperature to 70 DEG C, adding amount of substance is that the citric acid of 3.5 times of all metal ions amounts vigorous stirring are until solution becomes clear; Above-mentioned lithium-rich anode material powder is joined in clear liquid and forms suspension, continuing under the condition stirring, the temperature to 85 DEG C of rising suspension, slow evaporation moisture, until system becomes the muddy of thickness, by this material put into 160 DEG C of oven dryings after 20 hours, take out with the speed of 9 DEG C/min be warmed up to 550 DEG C calcining 10 hours after continue with the speed of 9 DEG C/min be warmed up to 950 DEG C calcining 20 hours, with the cooling Ni that obtains of stove²⁺，Mn⁴⁺，Si⁴⁺，Zn²⁺，F^-The Nasicon solid electrolyte LiTi of doping₂(PO₄)₃Layer-layer composite lithium-rich anode material of surface modification.

Embodiment 4: by LiNO₃∶MnSO₄·H₂O∶Ni(CH₃COO)₂·4H₂O=1.5: the ratio of 0.75: 0.25 (mol ratio) is evenly mixed, is dissolved in deionized water, and adding amount of substance is that the tartaric acid of 1.8 times of all metal ions total amounts stirs to dissolving completely; The temperature rise to 75 of system DEG C is continued to stir until 75% water evaporates, and at this moment solution becomes gradually thickness and forms gelatin. Gelatin material is ground 15 minutes after dry 20 hours in the baking oven of 160 DEG C in mortar. The powder obtaining is warmed up to 520 DEG C and this temperature lower calcination 4 hours with the speed of 4 DEG C/min in tube furnace, cooling rear taking-up powder, in mortar, continue to grind 10 minutes, powder is pressed into sheet with the pressure of 150MPa, then in tube furnace, be warmed up to 920 DEG C of calcinings 10 hours with the speed of 8 DEG C/min, obtain this lithium-rich anode material after cooling with stove. By LiNO₃、ZnSO₄·7H₂O、Ni(CH₃COO)₂·4H₂O、Mn(CH₃COO)₂·4H₂O, butyl titanate, tetraethyl orthosilicate, ammonium dihydrogen phosphate (ADP), LiF amount of substance ratio are=1.8: 0.4: 0.1: 0.1: 1.4: 0.2: 2.8: 0.2 joins in deionized water at normal temperature, its total amount of substance is lithium-rich anode material 6%, continue to stir rising system temperature to 60 DEG C, adding amount of substance is that the citric acid of 3.2 times of all metal ions amounts vigorous stirring are until solution becomes clear; Above-mentioned lithium-rich anode material powder is joined in clear liquid and forms suspension, continuing under the condition stirring, the temperature to 85 DEG C of rising suspension, slow evaporation moisture, until system becomes the muddy of thickness, by this material put into 160 DEG C of oven dryings after 20 hours, take out with the speed of 9 DEG C/min be warmed up to 520 DEG C calcining 10 hours after continue with the speed of 9 DEG C/min be warmed up to 930 DEG C calcining 20 hours, with the cooling Ni that obtains of stove²⁺，Mn⁴⁺，Si⁴⁺，Zn²⁺，F^-The Nasicon solid electrolyte LiTi of doping₂(PO₄)₃Layer-layer composite lithium-rich anode material of surface modification.

Embodiment 5: by CH₃COOLi∶Mn(CH₃COO)₂·4H₂O∶NiSO₄·6H₂O=1.3: the ratio of 0.65: 0.35 (mol ratio) is evenly mixed, is dissolved in deionized water, and adding amount of substance is that the tartaric acid of 1.4 times of all metal ions total amounts stirs to dissolving completely; The temperature rise to 78 of system DEG C is continued to stir until 80% water evaporates, and at this moment solution becomes gradually thickness and forms gelatin. Gelatin material is ground 15 minutes after dry 40 hours in the baking oven of 180 DEG C in mortar. The powder obtaining is warmed up to 600 DEG C and this temperature lower calcination 5 hours with the speed of 8 DEG C/min in tube furnace, cooling rear taking-up powder, in mortar, continue to grind 30 minutes, powder is pressed into sheet with the pressure of 250MPa, then in tube furnace, be warmed up to 950 DEG C of calcinings 15 hours with the speed of 9 DEG C/min, obtain this lithium-rich anode material after cooling with stove. By CH₃COOLi、Zn(NO₃)₂·6H₂O、Ni(CH₃COO)₂·4H₂O、Mn(CH₃COO)₂·4H₂O, butyl titanate, tetraethyl orthosilicate, ammonium dihydrogen phosphate (ADP), LiF amount of substance ratio are 1.6: 0.3: 0.05: 0.05: 1.6: 0.1: join at 2.9: 0.1 in deionized water at normal temperature, its total amount of substance is lithium-rich anode material 9%, continue to stir rising system temperature to 70 DEG C, adding amount of substance is that the citric acid of 3.3 times of all metal ions amounts vigorous stirring are until solution becomes clear; Above-mentioned lithium-rich anode material powder is joined in clear liquid and forms suspension, continuing under the condition stirring, the temperature to 80 DEG C of rising suspension, slow evaporation moisture, until system becomes the muddy of thickness, by this material put into 160 DEG C of oven dryings after 20 hours, take out with the speed of 9 DEG C/min be warmed up to 500 DEG C calcining 10 hours after continue with the speed of 9 DEG C/min be warmed up to 850 DEG C calcining 10 hours, with the cooling Ni that obtains of stove²⁺，Mn⁴⁺，Si⁴⁺，Zn²⁺，F^-The Nasicon solid electrolyte LiTi of doping₂(PO₄)₃Layer-layer composite lithium-rich anode material of surface modification.

Claims

1. a Ni²⁺，Mn⁴⁺，Si⁴⁺，Zn²⁺，F^-The compound lithium-rich anode material of layer-layer of the Nasicon type solid electrolyte surface modification of dopingMaterial, the stoichiometric equation that it is characterized in that surface reforming layer is Li_1+2x+m+z-yZn_x(Mn_0.5Ni_0.5)_mSi_zTi_2-x-mP_3-zO_12-yF_y, itsIn: x=0.1-0.5, y=0.1-0.2, m=0.1-0.3, z=0.1-0.3; The stoichiometric equation of layer-layer composite lithium-rich anode material isaLi₂MnO₃·(1-a)LiMn_0.5Ni_0.5O₂, 0≤a≤0.5; The amount of substance of surface reforming layer is the 1%-10% of positive electrode amount;Its preparation process is carried out in two steps; First, will be according to stoichiometric equation aLi₂MnO₃·(1-a)LiMn_0.5Ni_0.5O₂，0≤a≤0.5，Soluble lithium compounds, soluble manganese salt, soluble nickel salt be dissolved in deionized water, adding amount of substance is all metalsTotal ion concentration 1.2-2.0 tartaric acid doubly stirs to dissolving completely, and the temperature of rising system continues to stir to 70-85 DEG CUntil the water evaporating liquid of 70-85% become thickness and form gelatin, gelatin material is dry in the baking oven of 130-200 DEG CAfter 20-48 hour, in mortar, grind 10-30 minute, the powder obtaining speed with 2-10 DEG C/min in tube furnace is heated upTo 500-600 DEG C and at this temperature lower calcination 3-5 hour, cooling rear taking-up powder continues to grind 10-30 minute in mortar,Powder is pressed into sheet with the pressure of 100-300MPa, in tube furnace, is warmed up to 850-950 DEG C with the speed of 2-10 DEG C/min and forgesBurn 5-15 hour, with the cooling lithium-rich anode material that obtains of stove; Secondly, will be according to stoichiometric equation Li_1+2x+m+z-yZn_x(Mn_0.5Ni_0.5)_mSi_zTi_2-x-mP_3-zO_12-yF_y, wherein: x=0.1-0.5, y=0.1-0.2, m=0.1-0.3, z=0.1-0.3; Soluble lithium compounds,Soluble zinc salt, soluble nickel salt, soluble manganese salt, butyl titanate, tetraethyl orthosilicate, ammonium dihydrogen phosphate (ADP), LiF joinIn deionized water at normal temperature, also continue to stir, increase the temperature to 50-70 DEG C, adding amount of substance is all metal ions amount 2.5-3.5Citric acid doubly vigorous stirring are until solution becomes clear; Add the lithium-rich anode material powder that 10-100 doubly measures to form outstandingSupernatant liquid, is continuing under the condition stirring, and the temperature of rising suspension is to 75-85 DEG C, and slow evaporation moisture, until that system becomes is stickyThick muddy; This material is put into after 100-160 DEG C of oven drying 10-20 hour and taken out with the speed of 2-10 DEG C/min and heat upAfter 5-10 hour, continue to be warmed up to 850-950 DEG C of calcining 10-20 hour with the speed of 2-10 DEG C/min to 450-550 DEG C of calcining,With the cooling Ni that obtains of stove²⁺，Mn⁴⁺，Si⁴⁺，Zn²⁺，F^-The compound rich lithium of layer-layer of the Nasicon type solid electrolyte surface modification of dopingPositive electrode; Above-mentioned soluble lithium compounds is LiNO₃、CH₃One in COOLi; Soluble manganese salt isMn(CH₃COO)₂·4H₂O、MnSO₄·H₂One in O; Soluble nickel salt is Ni (CH₃COO)₂·4H₂O、NiSO₄·6H₂OIn one; Soluble zinc salt is ZnSO₄·7H₂O、Zn(NO₃)₂·6H₂One in O.