CN104600273B - A kind of phosphorous anode material for lithium-ion batteries and preparation method thereof - Google Patents

Abstract

The invention relates to a phosphorus-containing lithium ion battery cathode material and a preparation method thereof. The composition of the phosphorus-containing lithium ion battery cathode material is Li _a Mn _b Ni _c M _d P _e Z _f O _g , wherein M is at least one of Co, Al, Ti, Fe, Cr, Cu, Zr, Mg, and Z At least one of S and Si, and 0.95≤a<1.6, 0≤b<1, 0≤c≤0.9, 0≤d≤0.5, 0.001≤e<0.05, 0≤f<0.2, 1.95≤g< 2.5. The method for preparing this positive electrode material contains at least the following four steps: 1) using lithium source, phosphorus source, manganese source and nickel source, and selected from cobalt source, aluminum source, titanium source, iron source, chromium source, copper source, At least one of zirconium source, magnesium source, and at least one selected from sulfur source and silicon source are used as raw materials, and the corresponding raw materials are weighed by molar ratio; 2) adding liquid to the raw materials, and grinding; 3) grinding the ground drying the slurry; 4) roasting the dried material. The method has the advantages of simple process, low cost and easy industrial production, and the positive electrode material prepared by the method has high specific capacity. The invention also relates to batteries using this material as active material.

Description

A kind of phosphorus-containing lithium ion battery cathode material and preparation method thereof

technical field

The invention relates to the field of cathode materials for lithium ion batteries, in particular to a phosphorus-containing cathode material for lithium ion batteries and a preparation method thereof.

Background technique

The continuous development of industrial technology has caused the current situation of resource and energy shortages and environmental pollution to become increasingly serious. In recent years, countries around the world have introduced policies to promote the development of energy-saving and emission-reduction technologies and the development of new energy sources. Lithium-ion batteries have received widespread attention because of their advantages such as high operating voltage, light weight, long cycle life, wide allowable operating range, no memory effect, and no pollution, making them a popular choice for buses, electric vehicles, hybrid vehicles, etc. The main source of power for large vehicles, light electric vehicles such as electric bicycles, small flat-bed battery cars, and electric tools. However, as a power battery for large vehicles, lithium-ion batteries cannot meet the requirements in terms of specific energy, cycle life, safety and other aspects. The key factor that inhibits the development of power batteries is the positive electrode material of the battery, so the development of new positive electrode materials has become the most urgent problem to be solved now.

In recent years, lithium-rich solid solution cathode materials have become a research hotspot for lithium-ion battery cathode materials because of their advantages such as high specific capacity, good cycle stability, and high specific energy. The lithium-rich solid solution material is a solid solution formed by layered Li ₂ MnO ₃ and LiMO ₂ (M=Mn, Ni, Co) in different proportions, and its chemical formula can be written as xLi ₂ MnO ₃ ·(1-x)LiMO ₂ or xLi ₂ O· _yMOb (x/y>0.51). According to literature reports, there are many methods for preparing the above-mentioned cathode materials, such as co-precipitation method, sol-gel method, high-temperature solid-phase method, hydrothermal synthesis method, etc., among which co-precipitation method is the most commonly used. A. Manthiram et al prepared lithium-rich cathode material Li[Li _0.2 Mn _0.54 Ni _0.13 Co _0.13 ]O ₂ by co-precipitation method, and the first discharge specific capacity reached 250mAh/g (J.Phys.Chem.C., 114(2010) 9528-9533), but the cycle and rate performance are lacking, and the preparation process is complex and costly, so it is not suitable for large-scale industrial production. Samsung uses compounds of the following general formulas Li _x MnA ₂ (1), Li _x MnO _2-z A _z (2), Li _x Mn _1-y M′ _y A ₂ (3), Li _x Mn ₂ A ₄ ( 4), Li _x Mn ₂ O _4-z A _z (5), Li _x Mn _2-y M′ _y A ₄ (6), Li _x BO ₂ (7), Li _x BO _2-z A _z (8 ), Li _x B _1-y M″ _y A ₂ (9), Li _x B _1-y M″ _y O _2-z A _z (10), Li _x NiCoA ₂ (11), Li _x NiCoO _2-z A _z (12), Li _x Ni _1-yz Co _y M″ _z A ₂ (13) (wherein 0<x≤1.5, 0.01≤y≤0.1, 0.01≤z≤0.5, M′ is selected from Al, Cr, At least one of Co, Mg, La, Ce, Sr, V, M" is at least one selected from Al, Cr, Mn, Fe, Mg, LA, Ce, Sr, V, A is selected from O, F, S and P, and B are selected from Ni or Co) and selected from semimetals, metals and their oxides to form a positive electrode active material composition (CN1181580C), and this composition is likely to cause uneven distribution of components. Samsung Company selects the compounds represented by the general formulas (1) to (13) above, and coats vanadium pentoxide (CN1150645C) and metal oxide (CN1209832C) on the surface of these compounds. The coating thickness varies and the process Problems such as complexity and poor operability affect the performance of the material and increase the cost of the process.

Contents of the invention

Aiming at the existing problems of the anode materials of lithium ion batteries, the present invention provides a phosphorus-containing anode material of lithium ion batteries and a preparation method thereof, and is made into a cathode of a lithium ion battery and a lithium ion battery. Among them, phosphorus is added to the raw materials in the form of phosphate to prepare phosphorus-containing lithium-ion battery cathode materials, and the range of phosphorus in the lithium-ion battery cathode materials is given, which can improve the rate performance and cycle performance of the material, and then To meet the needs of power batteries for lithium-ion battery cathode materials.

A phosphorus-containing lithium ion battery positive electrode material, its chemical formula is Li _a Mn _b Ni _c M _d P _e Z _f O _g ,

Where M is at least one of Co, Al, Ti, Fe, Cr, Cu, Zr, Mg, Z is at least one of S and Si, and 0.95≤a<1.6; 0≤b≤1, preferably 0<b ≤0.9, preferably 0.05≤b≤0.9; 0≤c≤0.9, preferably 0.1≤c≤0.9; 0≤d≤0.5; 0.001≤e<0.050, preferably 0.001≤e≤0.040, preferably 0.006≤e≤0.020; ≤f<0.2, preferably 0.01≤f≤0.15, preferably 0.02≤f≤0.05; 1.95≤g<2.5.

According to the above-mentioned positive electrode material is one of the following compositions: Li _0.95 Mn _0.21 Ni _0.72 Co _0.19 P _0.04 S _0.01 O _2.03 , Li _1.17 Mn _0.52 Ni _0.12 Co _0.11 P _0.04 S _0.02 O _2.07 , Li _1.18 Mn _0.53 Ni _0.14 CO _0.13 P _0.04 S _0.05 O _2.235 , li _1.21 mn _{0.52 ni 0.13} CO _{0.12 P 0.02} Si _0.01 O _2.025 , Li _1.21 MN _0.53 Ni _0.13 CO _0.006 Si _0.02 O _{2.14 , Limn 0.52} CO _0.28 Al S _0.05 o _2.116 , _{li 1.211} mn _0.534 ni _0.129 CO _0.002 S _0.05 O _2.144 , _{LIMN 0.055} Ni _0.75 CO _0.21 Al _0.08 P _{0.005 S 0.28 Ni 0.58 CO 0.03Z AL 0.03Z AL 0.08} o _2.305 , li, _0.98 mn _0.28 ni _0.78 CO _0.16 Ti _0.02 Al _0.02 mg _0.03 P _0.03 S _0.01 O _2.261 , Li _1.04 mn _0.16 NI _0.76 AL _{0.05 mg 0.006} S _0.05 O _{2.11 ,} li _1.5 mn _{0.453 ni} CR _0.15 P _0.007 S _0.01 O _2.209 , Li _1.2 MN _0.54 Ni _0.13 CR _0.05 Al _0.03 mg _0.03 P _0.03 S _0.03 O _2.1 , Li _1.17 mn _0.50 ni _0.29 P _0.05 O _2.125 , Li _1.25 mn _0.40 Ni _0.32 CO _{0.05 mg 0.05} P _0.04 S _0.05 O _2.12 , LiMn _0.35 Ni _0.582 Mg _0.20 P _0.008 S _0.01 O _2.032 , LiMn _0.15 Ni _0.75 Co _0.15 CR _0.05 P _0.04 S _0.02 O _2.01 , Li _1.2 MN _0.6 Ni _0.15 CU _0.05 P _0.02 Si _0.01 O _2.07 , Li _1.35 mn _0.52 Ni _0.15 CU _{0.08 CR 0.006 Si 0.01} O _2.025 , Li _1.25 mn _0.06 CO _0.06 CO 0.06 CO 0.06 CO 0.06 CO 0.06 CO 0.06 CO 0.06 CO 0.06 CO 0.06 CO _0.06 CO 0 Cu _0.03 P _0.03 Si _0.02 O _2.1 , Li _0.95 Mn _0.28 Ni _0.70 Al _0.05 Cu _0.05 P _0.04 Si _0.05 O _2.06 , Li _1.25 Mn _0.62 Ni _0.06 Co _0.04 P _0.015 Si _0.1 O _2.23

The present invention also proposes a method for preparing a positive electrode material of a phosphorus-containing lithium ion battery, which at least contains the following four steps: 1) using a lithium source, a phosphorus source, a manganese source and a nickel source, and a material selected from a cobalt source and an aluminum source , titanium source, iron source, chromium source, copper source, zirconium source and magnesium source at least one, and sulfur source and/or silicon source, take the corresponding raw materials according to molar ratio; 2) according to the solid content is not more than 50% by weight That is, 0% by weight < solid content ≤ 50% by weight, and the balance is liquid, and liquid is added to the raw material for wet grinding, wherein the liquid is water, ethanol or an organic aqueous solution, and the concentration of the organic aqueous solution is not more than 50% by weight, that is, 0 % by weight<the concentration of the organic aqueous solution≤50% by weight, and the rest is water; 3) drying the ground slurry; 4) roasting the dried material at a temperature of 750 to 1100°C, and the preferred roasting temperature is 800～1000℃, the roasting time is 5～60h.

The lithium source is at least one of anhydrous lithium hydroxide, lithium hydroxide containing crystalline water, and lithium carbonate; the phosphorus source is phosphate, preferably at least one of diammonium hydrogen phosphate, ammonium dihydrogen phosphate, and ammonium phosphate; the manganese source is At least one of metallic manganese, manganese monoxide, manganese dioxide, and manganese carbonate; the nickel source is at least one of metallic nickel, nickelous oxide, nickel trioxide, nickel hydroxide, and nickel carbonate; the cobalt source is metallic cobalt, At least one of tricobalt tetroxide, dicobalt trioxide, cobaltous oxide, cobalt hydroxide, and cobalt carbonate; the aluminum source is at least one of metallic aluminum, aluminum oxide, and aluminum hydroxide; the titanium source is titanium dioxide or titanium isopropoxide Iron source is at least one of metallic iron, ferric oxide, ferric oxide, ferric hydroxide or ferrous hydroxide; chromium source is at least one of metallic chromium, dichromium trioxide, chromium hydroxide One; the copper source is at least one of copper oxide, cuprous oxide, and copper carbonate; the zirconium source is at least one of zirconium oxide and zirconium hydroxide; the magnesium source is at least one of magnesium carbonate and magnesium oxide; the manganese source, The nickel source and the cobalt source are at least one of manganese-nickel-cobalt alloy, manganese-nickel-cobalt hydroxide, manganese-nickel-cobalt oxyhydroxide, manganese-nickel-cobalt oxalate, manganese-nickel-cobalt, manganese-nickel-cobalt oxide; the manganese source and the nickel source are manganese-nickel Alloy, manganese nickel hydroxide, manganese nickel oxyhydroxide, manganese nickel oxalate, manganese nickel carbonate, manganese nickel oxide; manganese source and cobalt source are manganese cobalt alloy, manganese cobalt hydroxide, manganese cobalt oxyhydroxide, manganese oxalate At least one of cobalt, manganese-cobalt carbonate, and manganese-cobalt oxide; the nickel source and cobalt source are at least one of nickel-cobalt alloy, nickel-cobalt hydroxide, nickel-cobalt oxyhydroxide, nickel-cobalt oxalate, nickel-cobalt carbonate, and nickel-cobalt oxide; The sulfur source is sulfate, sulfite, sulfur oxide or sulfur hydride, preferably at least one of nickel sulfate or ammonium sulfate in the sulfate. The silicon source is silicon dioxide. The liquid used in the grinding process is at least one of deionized water, ethanol, ethanol aqueous solution, PVA aqueous solution, and sucrose aqueous solution; the dried slurry adopts at least one of vacuum drying, blast drying, spray drying, and microwave drying; The temperature is 800-1000°C.

The positive electrode material prepared according to the above method is mixed with conductive carbon and binder, and the obtained mixture is coated on a supporting conductive substrate to form the positive electrode of the lithium ion battery. The positive electrode, the electrically compatible anode, the separator, and the electrolyte are placed in a container to form a lithium-ion battery.

The positive electrode material prepared by the method of the invention is mixed with a conductive agent and a binder, dissolved in an organic solvent to form a positive electrode slurry, coated on a support body, and made into a positive electrode of a lithium ion battery.

The positive electrode is adopted, and the negative electrode that is electrically compatible with the positive electrode material prepared by the present invention is selected as the negative electrode of the lithium ion battery, and a diaphragm and an electrolyte are added to form the lithium ion battery.

The advantages of the present invention are:

Compared with the prior art, the present invention provides a phosphorus-containing lithium-ion battery positive electrode material and a preparation method thereof. This positive electrode material has high electrochemical performance, and the process is simple and easy to synthesize materials, thereby reducing costs. It is beneficial to industrialized continuous production.

Description of drawings

Fig. 1 is the full spectrum of the X-ray diffraction pattern [Fig. 1a] and the enlarged spectrum of 18-19.5° [Fig. 1b] of the positive electrode materials of Synthesis Example 1, Example 2, Example 3 and Example 4 of the present invention.

Fig. 2 is a comparison chart of the initial charge and discharge curves of the positive electrode materials synthesized in the present invention in Example 1, Example 2, Example 3 and Example 4 at 0.1C, 4.8-2.0V.

Fig. 3 is a graph comparing the rate performance curves of the cathode materials synthesized in the present invention in Example 1, Example 2, Example 3 and Example 4 at 0.1C and 4.8-2.0V.

Fig. 4 is a comparison chart of the first charge and discharge curves of materials synthesized in the present invention in Example 4 and Comparative Example 1, Comparative Example 2 and Comparative Example 3 at 4.8-2.0V.

Fig. 5 is a graph comparing rate performance curves of materials synthesized in the present invention in Example 4 and Comparative Example 1, Comparative Example 2 and Comparative Example 3 at 4.8-2.0V.

Detailed ways

The technical scheme of the present invention will be further described with the following examples, which will help to further understand the preparation method of the present invention. The protection scope of the present invention is not limited by these examples. The protection scope of the present invention is defined by the claims Decide.

Example 1:

Prepare Li _1.204 Mn _0.533 Ni _0.132 Co _0.131 P _0.001 O _2.02 , weigh 52.052g lithium carbonate, 71.692g manganese carbonate, 12.304g tricobalt tetroxide, 11.537g nickelous oxide and 0.136g ammonium dihydrogen phosphate, mix, add 1000g deionized water , added to a grinder for grinding, then spray-dried, the powder obtained after spray-drying was calcined at 900°C for 36 hours, cooled with the furnace, and the obtained powder was ground and passed through a 300-mesh sieve.

Example 2:

Prepare Li _1.18 Mn _0.53 Ni _0.14 Co _0.13 P _0.04 S _0.05 O _2.235 , weigh 52.246g lithium carbonate, 73.010g manganese carbonate, 12.505g tricobalt tetroxide, 12.531g nickelous oxide, 5.512g ammonium dihydrogen phosphate and 7.918g ammonium sulfate, Mix, add 1000g of deionized water, add it to a grinder and grind it, then spray dry it. The powder obtained after spray drying is calcined at 900°C for 36 hours, cooled with the furnace, and the obtained powder is ground and passed through 300 mesh screen.

Example 3:

To prepare Li _1.21 Mn _0.53 Ni _0.13 Co _0.13 P _0.006 Si _0.02 O _2.4 , weigh 48.615g of lithium carbonate, 66.252g of manganese carbonate, 11.347g of tricobalt tetroxide, 10.559g of nickel oxide, 0.750g of ammonium dihydrogen phosphate and 1.307g of silicon dioxide , mix, add 1000g of deionized water, add it to the grinder and grind it, then spray dry it, and the powder obtained after spray drying is calcined at 900°C for 36h, cooled with the furnace, the obtained powder is ground, and passed through 300 Mesh sieve.

Example 4:

Prepare Li _1.21 Mn _0.52 Ni _0.13 Co _0.12 P _0.02 Si _0.01 O _2.025 , weigh 52.612g lithium carbonate, 70.346g manganese carbonate, 11.335g tricobalt tetroxide, 11.427g nickelous oxide, 2.706g ammonium dihydrogen phosphate and 0.707g silicon dioxide , mix, add 800g of deionized water, add it to the grinder and grind it, then spray dry it, and the powder obtained after spray drying is calcined at 900°C for 36h, cooled with the furnace, the obtained powder is ground, and passed through 300 Mesh sieve.

Example 5:

Prepare Li _1.211 Mn _0.534 Ni _0.129 Co _0.124 P _0.002 S _0.05 O _2.144 , weigh 54.038g lithium carbonate, 74.137g manganese carbonate, 12.021g tricobalt tetroxide, 11.637g nickelous oxide, 0.278g ammonium dihydrogen phosphate and 15.874g nickel sulfate, Mix, add 1000g of deionized water, add it to a grinder and grind it, then spray dry it. After spray drying, the powder obtained is calcined at 900°C for 48 hours, cooled with the furnace, and the obtained powder is ground and passed through 300 mesh screen.

Embodiment 6:

Prepare Li _1.17 Mn _0.50 Ni _0.29 P _0.04 S _0.05 O _2.125 , weigh 48.323g lithium carbonate, 64.250g manganese carbonate, 24.214g nickel oxide, 5.141g ammonium dihydrogen phosphate and 14.292g nickel sulfate, mix, add 1000g deionized Water is added to the grinder for grinding, then spray-dried, and the powder obtained after spray-drying is calcined at 900°C for 48 hours, cooled with the furnace, and the obtained powder is ground and passed through a 300-mesh sieve.

Embodiment 7:

Prepare Li _1.17 Mn _0.50 Ni _0.29 P _0.04 S _0.05 O _2.125 , weigh 48.323g lithium carbonate, 48.595g manganese dioxide, 26.806g11.520g nickel trioxide, 5.141g ammonium dihydrogen phosphate and 7.386g ammonium sulfate, mix, Add 1000g of deionized water, add it to a grinder, grind it, and then spray dry it. The powder obtained after spray drying is calcined at 900°C for 48 hours, and cooled with the furnace. The obtained powder is ground and passed through a 300-mesh sieve.

Embodiment 8:

Prepare Li _1.2 Mn _0.54 Ni _0.13 Cr _0.05 Al _0.03 Mg _0.03 P _0.02 S _0.03 O _2.1 , weigh 54.801g lithium carbonate, 76.725g manganese carbonate, 12.002g nickel oxide, 3.214g metal chromium, 2.094g aluminum oxide, Mix 1.495g magnesium oxide, 2.842g ammonium phosphate and 4.900g ammonium sulfate, add 1000g deionized water, grind them in a grinder, and carry out microwave drying. The powder obtained after drying is calcined at 900°C for 36h, then The furnace is cooled, and the obtained powder is ground and passed through a 300-mesh sieve.

Embodiment 9:

Prepare Li _1.35 Mn _0.52 Ni _0.15 Cu _0.08 Cr _0.03 P _0.006 Si _0.01 O _2.025 , weigh 60.717g lithium carbonate, 55.035g manganese dioxide, 10.717g metal nickel, 7.747g copper oxide, 1.900g metal chromium, 0.840g diphosphate Mix ammonium hydrogen and 0.732g silicon dioxide, add 1000g deionized water, grind it in a grinder, and then dry it in vacuum. The body is ground and passed through a 300-mesh sieve.

Example 10:

Prepare Li _1.25 Mn _0.62 Ni _0.06 Co _0.02 Cu _0.03 P _0.03 Si _0.02 O _2.1 , weigh 54.694g lithium carbonate, 63.838g manganese dioxide, 4.170g metal nickel, 1.396g metal cobalt, 2.826g copper oxide, 4.085g diphosphate Mix ammonium hydrogen and 1.423g silicon dioxide, add 1000g deionized water, grind in a grinder, and carry out microwave drying. After drying, the powder obtained is calcined at 900°C for 12 hours, and cooled with the furnace. The obtained powder The body is ground and passed through a 300-mesh sieve.

Example 11:

To prepare Li _1.2 Mn _0.6 Ni _0.15 Cu _0.05 P _0.02 Si _0.01 O _2.07 , weigh 50.787g of lithium carbonate, 59.756g of manganese dioxide, 12.834g of nickel oxide, 4.556g of copper oxide, 3.024g of diammonium hydrogen phosphate and 0.688g of diammonium Silicon oxide, mix, add 1000g deionized water, add it to the grinder and grind it, then carry out blast drying, the powder obtained after drying is calcined at 950 °C for 24 hours, cooled with the furnace, the obtained powder is ground, and passed 300 mesh sieve.

Example 12:

Prepare Li _1.25 Mn _0.62 Ni _0.06 Co _0.04 P _0.015 Si _0.1 O 2.223 , weigh _52.834g of lithium carbonate, 81.486g of manganese carbonate, 5.124g of nickel oxide, 3.671g of tricobalt tetroxide, 1.672g of ammonium dihydrogen phosphate and 6.871g of silicon dioxide , mix, add 1200g of deionized water, add it to a grinder and grind it, then spray dry it. After spray drying, the powder obtained is calcined at 950°C for 12 hours, cooled with the furnace, and the obtained powder is ground and passed through 300 Mesh sieve.

Example 13

To prepare Li _1.15 Ni _0.52 Co _0.15 Al _0.05 Ti _0.30 P _0.006 Si0 _.01 O _2.03 , weigh 44.259g of lithium carbonate, 24.182g of nickel oxide, 12.993g of tricobalt tetroxide, 3.047g of aluminum oxide, 43.099g of titanium dioxide, and 0.745g of phosphoric acid Ammonium dihydrogen and 0.649g of silicon dioxide are mixed, 1200g of deionized water is added, and after grinding in a grinder, spray drying is carried out. The powder obtained after spray drying is calcined at 950°C for 12 hours, and then cooled with the furnace. The obtained powder is ground and passed through a 300-mesh sieve.

Example 14

Prepare Li _1.2 Mn _0.6 Co _0.10 Cu _0.05 P _0.02 S _0.01 O _2.07 , weigh 52.514g lithium carbonate, 81.693g manganese carbonate, 9.507g tricobalt tetroxide, 2.724g ammonium dihydrogen phosphate and 1.565g ammonium sulfate, mix, add 1200g deionized Water is added to the grinder for grinding, then spray-dried, and the powder obtained after spray-drying is calcined at 950°C for 12 hours, cooled with the furnace, and the obtained powder is ground and passed through a 300-mesh sieve.

Comparative example 1:

Prepare Li _1.20 Mn _0.54 Ni _0.13 Co _0.13 O ₂ , weigh 37.371g of lithium carbonate, 50.797g of manganese carbonate, 8.539g of cobalt tetroxide, 7.946g of nickelous oxide, mix, add 800g of deionized water, and grind in a grinder, Spray drying is carried out, and the powder obtained after spray drying is calcined at 900° C. for 36 hours, cooled with the furnace, and the obtained powder is ground and passed through a 300-mesh sieve.

Comparative example 2:

Prepare Li _1.19 Mn _0.53 Ni _0.15 Co _0.13 P _0.0005 O _2.01 , weigh 51.113g lithium carbonate, 70.824g manganese carbonate, 12.131g tricobalt tetroxide, 13.025g nickelous oxide and 0.403g ammonium sulfate, mix, add 800g deionized water, add After being ground in a grinder, it is spray-dried, and the powder obtained after spray-drying is calcined at 900°C for 36 hours, cooled with the furnace, and the obtained powder is ground and passed through a 300-mesh sieve.

Comparative example 3:

Prepare Li _1.132 Mn _0.490 Ni _0.123 Co _0.120 P _0.136 Si _0.005 O _2.289 , weigh 46.446g lithium carbonate, 65.551g manganese carbonate, 10.202g nickelous oxide, 10.696g tricobalt tetroxide, 17.366g ammonium dihydrogen phosphate and 0.334g silicon dioxide , mix, add 1000g of deionized water, add it to the grinder and grind it, then spray dry it, and the powder obtained after spray drying is calcined at 900°C for 36h, cooled with the furnace, the obtained powder is ground, and passed through 300 Mesh sieve.

Fig. 1 is the X-ray diffraction full spectrum [Fig. 1a] of the material prepared by embodiment 1, 2, 3 and 4 (the XRD collection of patterns of the material prepared by other specific embodiments is similar, omitted) and embodiment 1, 2, 3 and 4 The X-ray diffraction 18～19.6° spectrum of the prepared material [Fig. 1b], as can be seen from Fig. 1a, the prepared material is a layered α-NaFeO ₂ layered structure. As can be seen from Fig. 1b, the characteristic peak of the material Move slightly towards a small angle.

Positive electrode preparation

Use the materials prepared in Examples 1, 2, 3, 4 and Comparative Examples 1-3 as active materials, and weigh them with conductive agent (SP) and binder (PVDF) according to the ratio of 8:1:1. Dry mix the active material and the conductive agent for 4 hours, dissolve PVDF in N-N dimethylformamide, then add the conductive agent of the mixed active material to it, stir evenly to form a positive electrode slurry, and coat the positive electrode slurry on on aluminum foil and dry in the oven.

Half-cell preparation for materials testing

The dried electrode is cut into 1×1cm, then rolled, dried in a vacuum oven, and used as the positive electrode of the battery. The negative electrode of the battery is made of metal lithium. The main components of the electrolyte are 1M LiPF ₆ and DMC/EC/ DEC (1:1:1), put the positive electrode, negative electrode and electrolyte in the container to form the test battery.

Electrochemical performance test of materials

The assembled test battery was tested for its initial charge and discharge performance at a current density of 20mA/g (0.1C) and a charge and discharge voltage range of 4.8 to 2V. Test the rate performance of the battery at 0.1C, 0.2C, 0.5C, 1C, 2C, and 3C rates.

Using the positive electrode materials prepared in Example 1, Example 2, Example 3, and Example 4, the comparison chart of the first charge and discharge of the assembled battery is shown in Figure 2 . It can be seen from Figure 2 that the first charge specific capacity of Example 1 is 346.8mAh/g, the discharge specific capacity is 259.9mAh/g, the Coulombic efficiency is 74.9%, and the first charge specific capacity of Example 2 is 328.2mAh/g , the discharge specific capacity is 263.9mAh/g, the Coulombic efficiency is 80.2%, the first charge specific capacity of Example 3 is 353.9mAh/g, the discharge specific capacity is 277.1mAh/g, the Coulombic efficiency is 78.3%, the first The charge specific capacity is 369.7mAh/g, the discharge specific capacity is 283.6mAh/g, and the Coulombic efficiency is 76.7%.

Fig. 3 is the comparison chart of the rate performance of the lithium-ion battery assembled by the positive electrode material prepared in Example 1, 2, 3 and 4, the positive electrode material prepared in Example 1, assembled lithium-ion battery, and the discharge specific capacity of the battery at 0.1C is 259.9 mAh/g, the discharge specific capacity of 0.2C is 235.5mAh/g, the discharge specific capacity of 0.5C is 217.8mAh/g, the discharge specific capacity of 1C is 197.2mAh/g, the discharge specific capacity of 3C is 154.1mAh/g, Finally, the discharge specific capacity back to 0.1C is 236.1mAh/g. The positive electrode material prepared in Example 2 was assembled into a lithium-ion battery. The discharge specific capacity of the battery at 0.1C was 263.9mAh/g, the discharge specific capacity at 0.2C was 249.3mAh/g, and the discharge specific capacity at 0.5C was 225.3mAh/g , the discharge specific capacity of 1C is 196.2mAh/g, the discharge specific capacity of 3C is 157.3mAh/g, and finally the discharge specific capacity of 0.1C is 252.5mAh/g. The positive electrode material prepared in Example 3 was assembled into a lithium-ion battery. The discharge specific capacity of the battery at 0.1C was 277.1mAh/g, the discharge specific capacity at 0.2C was 253.5mAh/g, and the discharge specific capacity at 0.5C was 232.8mAh/g , the discharge specific capacity of 1C is 210.0mAh/g, the discharge specific capacity of 3C is 173.2mAh/g, and finally the discharge specific capacity of 0.1C is 257.2mAh/g. The positive electrode material prepared in Example 4 was assembled into a lithium-ion battery. The discharge specific capacity of the battery at 0.1C was 283.6mAh/g, the discharge specific capacity at 0.2C was 258.0mAh/g, and the discharge specific capacity at 0.5C was 235.4mAh/g , the discharge specific capacity of 1C is 220.9mAh/g, the discharge specific capacity of 3C is 185.5mAh/g, and finally the discharge specific capacity of 0.1C is 262.1mAh/g.

Fig. 4 is the first charge and discharge comparison chart of the battery assembled with positive electrode materials prepared in Example 4 and Comparative Example 1, Comparative Example 2, and Comparative Example 3. It can be seen from Fig. 5 that the first charge specific capacity of Example 4 is 369.7 mAh/g, the discharge specific capacity is 283.6mAh/g, and the Coulombic efficiency is 76.7%, while the first charge specific capacity of Comparative Example 1 is 319.7mAh/g, the discharge specific capacity is 248.8mAh/g, and the Coulombic efficiency is 77.8%. The first charge specific capacity of example 2 is 335.7mAh/g, the discharge specific capacity is 231.6mAh/g, the coulombic efficiency is 69.0%, the first charge specific capacity of comparative example 3 is 252.8mAh/g, the discharge specific capacity is 195.2mAh/g , and the Coulombic efficiency was 77.2%. In comparative example 1, phosphorus was not added, in comparative example 2, the phosphorus added was low, and in comparative example 3, phosphorus was too high and silicon was too low. Discharge specific capacity will be adversely affected.

Figure 5 is a comparison chart of the rate performance of lithium-ion batteries assembled with positive electrode materials prepared in Example 4 and Comparative Example 1, Comparative Example 2, and Comparative Example 3. The rate performance of Example 4 is mentioned above, and the positive electrode material prepared in Comparative Example 1 , Assemble a lithium-ion battery, the discharge specific capacity of the battery at 0.1C is 248.8mAh/g, the discharge specific capacity at 0.2C is 220.4mAh/g, the discharge specific capacity at 0.5C is 198.4mAh/g, and the discharge specific capacity at 1C is 179.9mAh/g, the discharge specific capacity of 3C is 146.7mAh/g, and finally the discharge specific capacity of 0.1C is 230.5mAh/g. The positive electrode material prepared in Comparative Example 2 was assembled into a lithium-ion battery. The discharge specific capacity of the battery at 0.1C was 231.6mAh/g, the discharge specific capacity at 0.2C was 193.4mAh/g, and the discharge specific capacity at 0.5C was 178.1mAh/g. , the discharge specific capacity of 1C is 169.9mAh/g, the discharge specific capacity of 3C is 124.7mAh/g, and finally the discharge specific capacity of 0.1C is 202.1mAh/g. The positive electrode material prepared in Comparative Example 3 was assembled into a lithium-ion battery. The discharge specific capacity of the battery at 0.1C was 195.2mAh/g, the discharge specific capacity at 0.2C was 184.3mAh/g, and the discharge specific capacity at 0.5C was 163.8mAh/g. , the discharge specific capacity of 1C is 146.5mAh/g, the discharge specific capacity of 3C is 123.1mAh/g, and finally the discharge specific capacity of 0.1C is 194.5mAh/g. The data show that the discharge of the positive electrode material prepared in Example 4 is better than that of Comparative Examples 1, 2 and 3. Adding silicon or sulfur to the phosphorus-containing lithium-rich material can not only improve the first charge and discharge performance of the material, but also The material also exhibits excellent electrochemical performance at high rates. Combining the above data, the method provided by the present invention not only saves the cost in the process, but also the performance of the material meets the requirements of the power battery, and this method can be applied to industrial production.

The positive electrode materials prepared in Examples 5-14 are assembled into lithium-ion batteries, and the discharge performance data at different rates are shown in the following table in the voltage range of 4.8-2.0V.

Claims (36)

1. a kind of phosphorous anode material for lithium-ion batteries, chemical formula Li_aMn_bNi_cM_dP_eZ_fO_g, wherein M be Co, Al, Ti, At least one of Fe, Cr, Cu, Zr, Mg, at least one of Z S, Si, and 0.95≤a<1.6,0≤b≤1,0≤c≤0.9,0 ≤ d≤0.5,0.006≤e≤0.020,0.01≤f≤0.15,1.95≤g<2.5.

2. a kind of phosphorous anode material for lithium-ion batteries according to claim 1, which is characterized in that 0<b≤0.9.

3. a kind of phosphorous anode material for lithium-ion batteries according to claim 1, which is characterized in that 0.05≤b≤ 0.9。

4. a kind of phosphorous anode material for lithium-ion batteries according to claim 1, which is characterized in that 0.1≤c≤0.9.

5. a kind of phosphorous anode material for lithium-ion batteries according to claim 1, which is characterized in that 0.02≤f≤ 0.05。

6. a kind of phosphorous anode material for lithium-ion batteries according to claim 1, which is characterized in that the positive material Material is one kind in consisting of：Li_1.21Mn_0.52Ni_0.13Co_0.12P_0.02Si_0.01O_2.025、 Li_1.21Mn_0.53Ni_0.13Co_0.13P_0.006Si_0.02O_2.14、、LiMn_0.28Ni_0.58Co_0.18Al_0.03Zr_0.03P_0.02S_0.08O_2.305、 Li_1.04Mn_0.16Ni_0.76Fe_0.16Al_0.05Mg_0.03P_0.006S_0.05O_2.11、Li_1.5Mn_0.453Ni_0.28Cr_0.15P_0.007S_0.01O_2.209、 Li_1.2Mn_0.54Ni_0.13Cr_0.05Al_0.03Mg_0.03P_0.02S_0.03O_2.1、、LiMn_0.35Ni_0.582Mg_0.20P_0.008S_0.01O_2.032、 Li_1.2Mn_0.6Ni_0.15Cu_0.05P_0.02Si_0.01O_2.07、Li_1.35Mn_0.52Ni_0.15Cu_0.08Cr_0.03P_0.006Si_0.01O_2.025、 Li_1.25Mn_0.62Ni_0.06Co_0.04P_0.015Si_0.1O_2.223。

7. a kind of method preparing phosphorous anode material for lithium-ion batteries described in claim 1, which is characterized in that at least contain There are following 4 steps：

1) with lithium source, phosphorus source, manganese source and nickel source, and in cobalt source, silicon source, titanium source, source of iron, chromium source, copper source, zirconium source and magnesium source At least one, and it is used as raw material selected from least one of sulphur source and silicon source, weigh corresponding original by the molar ratio of the chemical formula Material；

2) liquid is added in the feed, carries out wet-milling, is not more than 50 weight % i.e. 0 weight %&lt by solid content;The weight of solid content≤50 % is measured, surplus is liquid, and liquid is water, ethyl alcohol or aqueous organopolysiloxane, wherein the concentration of aqueous organopolysiloxane is no more than 50 weights Measure % i.e. 0 weight %<The weight % of the concentration of aqueous organopolysiloxane≤50, remaining is water；

3) the good slurry of wet-milling is dried；

4) material after drying is roasted, calcination temperature is 750~1100 DEG C, and roasting time is 5~60h.

8. the preparation method of positive electrode according to claim 7, which is characterized in that the lithium source is anhydrous hydroxide At least one of lithium, the water lithium hydroxide containing crystallization, lithium carbonate.

9. the preparation method of positive electrode according to claim 7, which is characterized in that the phosphorus source is phosphate or phosphorus Oxide.

10. the preparation method of positive electrode according to claim 9, which is characterized in that the phosphorus source is phosphate.

11. the preparation method of positive electrode according to claim 10, which is characterized in that the phosphorus source is phosphoric acid hydrogen two At least one of ammonia, ammonium di-hydrogen phosphate, phosphoric acid ammonia.

12. the preparation method of positive electrode according to claim 10, which is characterized in that the phosphorus source is phosphoric acid hydrogen two Ammonia.

13. the preparation method of positive electrode according to claim 10, which is characterized in that the phosphorus source is biphosphate Ammonia.

14. the preparation method of positive electrode according to claim 7, which is characterized in that the manganese source is manganese metal, one At least one of manganese oxide, manganese dioxide, manganese carbonate.

15. the preparation method of positive electrode according to claim 7, which is characterized in that the nickel source is metallic nickel, oxygen Change at least one of sub- nickel, nickel sesquioxide, nickel hydroxide, nickelous carbonate.

16. the preparation method of positive electrode according to claim 7, which is characterized in that the cobalt source is metallic cobalt, four At least one of Co 3 O, cobalt sesquioxide, cobalt protoxide, cobalt hydroxide, cobalt carbonate.

17. the preparation method of positive electrode according to claim 7, which is characterized in that the silicon source is metallic aluminium, three At least one of Al 2 O, aluminium hydroxide.

18. the preparation method of positive electrode according to claim 7, which is characterized in that the titanium source be titanium dioxide, At least one of titanium isopropoxide.

19. the preparation method of positive electrode according to claim 7, which is characterized in that the source of iron is metallic iron, three Aoxidize at least one of two iron, ferroso-ferric oxide, iron hydroxide, ferrous hydroxide.

20. the preparation method of positive electrode according to claim 7, which is characterized in that the chromium source is crome metal, three Aoxidize at least one of two chromium, chromium hydroxide.

21. the preparation method of positive electrode according to claim 7, which is characterized in that the copper source is copper oxide, oxygen Change at least one of cuprous, copper carbonate.

22. the preparation method of positive electrode according to claim 7, which is characterized in that the zirconium source is zirconium oxide, hydrogen At least one of zirconium oxide.

23. the preparation method of positive electrode according to claim 7, which is characterized in that the magnesium source is magnesium carbonate, oxygen Change at least one of magnesium.

24. the preparation method of positive electrode according to claim 7, which is characterized in that manganese source, nickel source and the cobalt source It is aoxidized in manganese nickel cobalt, oxalic acid manganese nickel cobalt, carbonic acid manganese nickel cobalt, oxidation manganese nickel cobalt extremely for manganese nickel cobalt alloy, manganous hydroxide nickel cobalt, hydroxyl Few one kind.

25. the preparation method of positive electrode according to claim 7, which is characterized in that the manganese source and nickel source is manganese At least one of nickel alloy, manganous hydroxide nickel, hydroxyl manganese oxide nickel, manganese oxalate nickel, manganese carbonate nickel, manganese oxide nickel.

26. the preparation method of positive electrode according to claim 7, which is characterized in that the manganese source and cobalt source is manganese At least one of cobalt alloy, manganous hydroxide cobalt, hydroxyl manganese oxide cobalt, manganese oxalate cobalt, manganese carbonate cobalt, manganese oxide cobalt.

27. the preparation method of positive electrode according to claim 7, which is characterized in that the nickel source and cobalt source is nickel At least one of cobalt alloy, hydroxide nickel cobalt, hydroxy cobalt nickel oxide, oxalic acid nickel cobalt, carbonic acid nickel cobalt, cobalt nickel oxide.

28. the preparation method of positive electrode according to claim 7, which is characterized in that the sulphur source is sulfate, Asia The hydride of sulfate, sulfur oxide or sulphur.

29. the preparation method of positive electrode according to claim 28, which is characterized in that the sulphur source is sulfate.

30. the preparation method of positive electrode according to claim 28, which is characterized in that the sulphur source be nickel sulfate or At least one of ammonium sulfate.

31. the preparation method of positive electrode according to claim 7, which is characterized in that the silicon source is silica.

32. the preparation method of positive electrode according to claim 7, which is characterized in that the water is deionized water；Institute The aqueous organopolysiloxane stated is at least one of aqueous solution, PVA aqueous solutions, aqueous sucrose solution of ethyl alcohol.

33. the preparation method of positive electrode according to claim 7, which is characterized in that the drying be vacuum drying, At least one of forced air drying, spray drying, microwave drying.

34. the preparation method of positive electrode according to claim 7, which is characterized in that the temperature of roasting is 800~1000 ℃。

35. a kind of anode of lithium ion battery, which is characterized in that with described in any one of claim 1-6 positive electrode or The positive electrode prepared according to any one of claim 7-34 the methods is mixed with conductive carbon and bonding agent, and will To mixture coated in the anode for forming the lithium ion battery on support conducting base.

36. a kind of lithium ion battery, which is characterized in that by the anode compatible with electricity of the anode described in claim 35, diaphragm, electricity Solution matter, which is placed in container, forms lithium ion battery.