CN103972495A - Preparation method of lithium ion battery positive pole material lithium nickelate manganate - Google Patents

Abstract

The invention relates to a preparation method of a lithium ion battery positive pole material lithium nickelate manganate. The invention belongs to the technical field of lithium ion batteries. The preparation method comprises the following steps: (1) preparation of metastable-state nickel manganese or nickel manganese oxide nanocrystal powder by mechanical alloying: adding a ball milling medium into Ni and Mn simple substances or oxides according to the stoichiometric proportion, and carrying out mechanical ball milling at the rotation speed of 300-500 r/min according to the grinding medium-to-material ratio of (10-50):1; (2) preparation of nickel manganese oxide presintered precursor: keeping the metastable-state nickel manganese or nickel manganese oxide nanocrystal powder prepared in the step (1) in an air or oxygen atmosphere at the constant temperature of 100-300 DEG C for 3-5 hours; and (3) preparation of lithium ion battery positive pole material lithium nickelate manganate by calcining: mixing a lithium source (2-5% excessive) and the nickel manganese oxide presintered precursor, calcining at 700-900 DEG C for 5-10 hours, cooling, grinding and screening. The method has the advantages of high yield, fewer foreign phases, high specific capacity, favorable loop stability, low energy consumption, low cost, simplified technological conditions, environment friendliness and the like.

Description

A kind of preparation method of lithium nickel manganese oxide lithium ion battery cathode material

technical field

The invention belongs to the technical field of lithium ion batteries, in particular to a preparation method of lithium nickel manganese oxide, a cathode material of lithium ion batteries.

Background technique

At present, the spinel-type lithium nickel manganese oxide (LiNi _0.5 Mn _1.5 O ₄ ) material has become an important material due to its high voltage platform, high energy density, good thermal stability, abundant raw material resources, low price, and environmental friendliness. A material with great potential for lithium-ion power batteries.

In the prior art, methods for synthesizing lithium nickel manganese oxide (LiNi _0.5 Mn _1.5 O ₄ ) mainly include solid-phase method, co-precipitation method, sol-gel method, hydrothermal method, ultrasonic spray drying pyrolysis method and the like.

Co-precipitation method and sol-gel method are complicated in process, high in production cost, and easily produce waste water and waste gas; hydrothermal method and ultrasonic spray drying pyrolysis method have high requirements on equipment, cumbersome operation, and immature technology; so they are currently suitable for industrial production The most common method is the solid phase method.

The solid-phase method is generally a one-step mixing and sintering method, that is, it is prepared by using lithium, nickel, and manganese compounds after being fully mixed and calcined at high temperature. The process is simple and the cost of manufacturing equipment is low. The disadvantage is that it is easy to generate oxide materials with uneven composition, resulting in slightly poor material consistency and low gram capacity; lithium and nickel atomic radii are similar, resulting in dislocation and mixing of Li and Ni in the crystal structure, resulting in active conversion of materials The rate is getting lower and lower, and the cycle stability is not good; and because of the wide distribution of material particles, there are technical problems such as poor subsequent processing performance.

Contents of the invention

In order to solve the technical problems in the known technology, the invention provides a preparation method of lithium nickel manganese oxide, a cathode material of a lithium ion battery.

The purpose of the present invention is to provide a lithium-ion battery cathode material nickel with high yield, less impurity phase, high specific capacity, good cycle stability, low energy consumption, simplified process conditions, reduced production cost, and environmental friendliness. The preparation method of lithium manganate.

The invention creatively adopts a mechanical alloying method to prepare lithium nickel manganese oxide, a cathode material of a lithium ion battery. The mechanical alloying method is mainly to put the metal or alloy powder in the high-energy ball mill through the long-term violent impact and collision between the powder particles and the grinding ball, so that the powder particles repeatedly undergo cold welding and fracture, resulting in the diffusion of atoms in the powder particles and becoming a sub-alloy. The method of steady-state ultrafine particles, that is, the method of mechanical activation to generate nanocrystalline particles.

The present invention combines the advantages of the solid-phase method and the liquid-phase precipitation method, and adopts a two-step synthesis method, that is, the components are obtained by mechanical alloying of nickel, manganese or their oxides, activated by mechanical ball milling, and calcined in air or oxygen atmosphere. The uniform nickel manganese oxide is added with a lithium source compound and then calcined at a high temperature to obtain a lithium nickel manganese oxide cathode material.

The technical scheme adopted in the preparation method of lithium ion battery cathode material lithium nickel manganese oxide of the present invention is:

A preparation method of lithium nickel manganese oxide lithium ion battery cathode material is characterized in that: the mechanical alloying method is used to prepare lithium ion battery cathode material nickel manganese oxide lithium, comprising the following process steps:

(1) Mechanical alloying to prepare metastable nickel-manganese or nickel-manganese oxide nanocrystalline powder

According to the stoichiometric ratio of Ni, Mn simple substance or oxide, add ball milling medium, under the conditions of rotating speed 300-500r/min, ball-to-material ratio 10-50:1, mechanical ball milling 3-100h, mechanical alloying method to obtain sub- Steady-state nickel-manganese or nickel-manganese oxide nanocrystalline powder;

(2) Preparation of pre-fired precursor of nickel manganese oxide

Place the metastable nickel-manganese or nickel-manganese oxide nanocrystalline powder prepared in step (1) in an air or oxygen atmosphere at a constant temperature of 100-300°C for 3-5 hours to obtain a nickel-manganese oxide pre-calcined precursor ;

Preparation of lithium nickel manganese oxide as cathode material for lithium ion battery by calcination

Mix a stoichiometric excess of 2-5% lithium source compound with a nickel-manganese oxide pre-calcined precursor, calcinate at 700-900° C. for 5-10 hours, cool to room temperature with the furnace, grind and sieve to obtain a lithium nickel manganese oxide product.

The preparation method of lithium-ion battery cathode material lithium nickel manganese oxide of the present invention can also adopt following technical scheme:

The preparation method of the lithium-ion battery cathode material lithium nickel manganese oxide is characterized in that when the metastable nickel-manganese or nickel-manganese oxide nanocrystalline powder is prepared by mechanical alloying, the purity of the elemental Ni is greater than 99.5%, and the purity of the elemental Mn The purity is greater than 99.8%.

The preparation method of the lithium-ion battery cathode material nickel manganese oxide is characterized in that: when preparing metastable nickel-manganese or nickel-manganese oxide nanocrystalline powder by mechanical alloying, the oxide of nickel is NiO or _{Ni2O 3.} Manganese oxide is any one or several of MnO, Mn ₂ O ₃ , Mn ₃ O ₄ , and MnO ₂ .

The preparation method of lithium nickel manganese oxide lithium ion battery anode material is characterized in that: when preparing metastable nickel manganese or nickel manganese oxide nanocrystalline powder by mechanical alloying, the ball milling medium is petroleum ether or absolute ethanol.

The preparation method of the lithium nickel manganese oxide cathode material for lithium ion batteries is characterized in that: when preparing lithium nickel manganese oxide lithium ion battery cathode material by calcining, the lithium source compound is Li ₂ CO ₃ , LiOH·H ₂ O, LiOH, One or a mixture of Li ₂ O or CH ₃ COOLi·2H ₂ O.

The preparation method of lithium nickel manganese oxide, the positive electrode material of lithium ion battery, is characterized in that: when preparing lithium nickel manganese oxide, the positive electrode material of lithium ion battery, the lithium nickel manganese oxide product is obtained by grinding and sieving after being cooled to room temperature in the furnace.

The advantages and positive effects that the present invention has are:

The preparation method of Lithium Nickel Manganese Oxide, the cathode material of lithium ion battery, has the following characteristics compared with the prior art due to the adoption of the brand-new technical solution of the present invention:

1. The raw material of the present invention is a simple substance or an oxide, and it is a solid phase reaction, so almost no three wastes are generated from the raw material to the product, the yield is high, the environment is friendly, and the production cost is low.

2. Compared with the one-step mixing and sintering method, the solid-phase two-step synthesis method in the present invention avoids the mixing of lithium and nickel, reduces the generation of impurity phases, improves the consistency of the product, and increases the specific capacity and cycle stability of the material ; Another particle size distribution tends to be uniform, easier to process.

3. Since the present invention utilizes the conditions of the mechanical alloying method to prepare the metastable nanocrystalline powder, the activity is high, the subsequent calcination temperature is low, and the energy consumption is reduced.

Description of drawings

Fig. 1 is the SEM figure of LiNi _0.5 Mn _1.5 O ₄ materials prepared by the present invention;

Fig. 2 is the XRD pattern of LiNi _0.5 Mn _1.5 O ₄ materials prepared by the present invention;

Fig. 3 is LiNi _0.5 Mn _1.5 O ₄ materials prepared by the present invention charge and discharge curve for the first time;

Fig. 4 is the first 100 1C discharge capacity curves of the LiNi _0.5 Mn _1.5 O ₄ material prepared in the present invention.

Detailed ways

In order to further understand the invention content, characteristics and effects of the present invention, the following examples are given, and detailed descriptions are as follows in conjunction with the accompanying drawings:

Refer to accompanying drawing 1, Fig. 2, Fig. 3 and Fig. 4.

Example 1

A preparation method of lithium nickel manganese oxide lithium ion battery positive electrode material, the present embodiment obtains 18.30g (0.10mol) LiNi _0.5 Mn _1.5 O ₄ positive electrode material, specifically comprising the following process steps:

(1) Mechanical alloying to prepare metastable nickel-manganese or nickel-manganese oxide nanocrystalline powder

Weigh 2.95g (0.05mol) of elemental Ni and 8.25g (0.15mol) of elemental Mn and mix them, add 10mL of petroleum ether, and perform mechanical ball milling for 48 hours under the conditions of a rotating speed of 500r/min and a ball-to-material ratio of 40:1 to obtain sub Stable nickel-manganese nanocrystalline powder.

(2) Preparation of pre-fired precursor of nickel manganese oxide

The nickel-manganese nanocrystalline powder was placed in an oxygen atmosphere at a constant temperature of 300° C. for 5 hours to obtain a nickel-manganese oxide precursor.

(3) Calcination to prepare lithium nickel manganese oxide, the cathode material for lithium-ion batteries

Mix 4.41g (0.105mol) LiOH·H ₂ O with nickel manganese oxide precursor, calcinate at 750°C for 10h, cool to room temperature with the furnace, grind and sieve to obtain LiNi _0.5 Mn _1.5 O ₄ product.

Example 2

A preparation method of lithium nickel manganese oxide lithium ion battery positive electrode material, the present embodiment obtains 36.60g (0.20mol) LiNi _0.5 Mn _1.5 O ₄ positive electrode material, specifically comprising the following process steps:

(1) Mechanical alloying to prepare metastable nickel-manganese or nickel-manganese oxide nanocrystalline powder

Weigh 7.50g (0.10mol) of NiO and 16.50g (0.30mol) of elemental Mn, add 25mL of petroleum ether, and perform mechanical ball milling for 48 hours at a speed of 450r/min and a ball-to-material ratio of 20:1 to obtain metastable state nickel manganese nanocrystalline powder.

(2) Preparation of pre-fired precursor of nickel manganese oxide

The nickel-manganese nanocrystalline powder was placed in an oxygen atmosphere at a constant temperature of 350° C. for 3 hours to obtain a nickel-manganese oxide precursor.

(3) Calcination to prepare lithium nickel manganese oxide, the cathode material for lithium-ion batteries

Mix 7.70g (0.104mol) Li ₂ CO ₃ and nickel manganese oxide precursor thoroughly, calcinate at 800°C for 8 hours, cool down to room temperature with furnace, grind and sieve to obtain LiNi _0.5 Mn _1.5 O ₄ product.

Example 3

A preparation method of lithium nickel manganese oxide lithium ion battery positive electrode material, the present embodiment obtains 18.30g (0.10mol) LiNi _0.5 Mn _1.5 O ₄ positive electrode material, specifically comprising the following process steps:

(1) Mechanical alloying to prepare metastable nickel-manganese or nickel-manganese oxide nanocrystalline powder

Weigh 2.95g (0.05mol) of elemental Ni and 11.44g (0.05mol) of Mn ₃ O ₄ , mix them, add 15mL of absolute ethanol, and perform mechanical ball milling for 24 hours at a speed of 450r/min and a ball-to-material ratio of 40:1. , to obtain metastable nickel-manganese nanocrystalline powder.

(2) Preparation of pre-fired precursor of nickel manganese oxide

The nickel-manganese nanocrystalline powder was placed in an oxygen atmosphere at a constant temperature of 300° C. for 4 hours to obtain a nickel-manganese oxide precursor.

(3) Calcination to prepare lithium nickel manganese oxide, the cathode material for lithium-ion batteries

Mix 3.85g (0.052mol) Li ₂ CO ₃ with the nickel manganese oxide precursor, calcinate at 800°C for 6 hours, cool to room temperature with the furnace, grind and sieve to obtain the LiNi _0.5 Mn _1.5 O ₄ product.

Example 4

A preparation method of lithium nickel manganese oxide lithium ion battery positive electrode material, the present embodiment obtains 36.60g (0.20mol) LiNi _0.5 Mn _1.5 O ₄ positive electrode material, specifically comprising the following process steps:

(1) Mechanical alloying to prepare metastable nickel-manganese or nickel-manganese oxide nanocrystalline powder

Weigh 7.50 g (0.10 mol) of NiO and 22.88 g (0.10 mol) of Mn ₃ O _{4 ,} mix them, add 30 mL of absolute ethanol, and perform mechanical ball milling for 60 h at a speed of 450 r/min and a ball-to-material ratio of 20:1. A metastable nickel-manganese nanocrystalline powder was obtained.

(2) Preparation of pre-fired precursor of nickel manganese oxide

The nickel-manganese nanocrystalline powder was placed in an oxygen atmosphere at a constant temperature of 350° C. for 4 hours to obtain a nickel-manganese oxide precursor.

(3) Calcination to prepare lithium nickel manganese oxide, the cathode material for lithium-ion batteries

Mix 7.62g (0.103mol) Li ₂ CO ₃ and nickel manganese oxide precursor thoroughly, calcinate at 800°C for 8 hours, cool to room temperature with furnace, grind and sieve to obtain LiNi _0.5 Mn _1.5 O ₄ product.

This embodiment has positive effects such as high product yield, less impurity phase, high specific capacity, good cycle stability, low energy consumption, simplified process conditions, reduced production cost, and environmental friendliness.

Claims (6)

1. a preparation method for lithium ion battery anode material nickel LiMn2O4, is characterized in that: adopt mechanical alloying method to prepare lithium ion battery anode material nickel LiMn2O4, comprise following processing step:

(1) metastable state nickel manganese or Ni, Mn oxide nanocrystalline powder are prepared in mechanical alloying

Adding Ni, Mn simple substance or oxide by stoichiometric proportion, add ball-milling medium, is under 300-500r/min, the ratio of grinding media to material condition that is 10-50:1 at rotating speed, mechanical ball milling 3-100h, and mechanical alloying method makes metastable state nickel manganese or Ni, Mn oxide nanocrystalline powder;

(2) prepare Ni, Mn oxide pre-burning presoma

Metastable state nickel manganese prepared by step (1) or Ni, Mn oxide nanocrystalline powder, be placed in constant temperature under 100-300 DEG C of condition of air or oxygen atmosphere and keep 3-5h, obtains Ni, Mn oxide pre-burning presoma;

(3) lithium ion battery anode material nickel LiMn2O4 is prepared in calcining

The Li source compound of the excessive 2-5% of stoichiometry is mixed with Ni, Mn oxide pre-burning presoma, in 700-900 DEG C of calcining 5-10h, cool to the furnace and grind the nickel LiMn2O4 product that sieves to obtain after room temperature.

2. the preparation method of lithium ion battery anode material nickel LiMn2O4 according to claim 1, it is characterized in that: when metastable state nickel manganese or Ni, Mn oxide nanocrystalline powder are prepared in mechanical alloying, the purity of simple substance Ni is greater than 99.5%, and the purity of simple substance Mn is greater than 99.8%.

3. the preparation method of lithium ion battery anode material nickel LiMn2O4 according to claim 1, is characterized in that: when metastable state nickel manganese or Ni, Mn oxide nanocrystalline powder are prepared in mechanical alloying, the oxide of nickel is NiO or Ni ₂o ₃, the oxide of manganese is MnO, Mn ₂o ₃, Mn ₃o ₄, MnO ₂in any one and several.

4. according to the preparation method of the lithium ion battery anode material nickel LiMn2O4 described in claim 1,2 or 3, it is characterized in that: when metastable state nickel manganese or Ni, Mn oxide nanocrystalline powder are prepared in mechanical alloying, ball-milling medium is benzinum or absolute ethyl alcohol.

5. according to the preparation method of the lithium ion battery anode material nickel LiMn2O4 described in claim 1,2 or 3, it is characterized in that: when lithium ion battery anode material nickel LiMn2O4 is prepared in calcining, Li source compound is Li ₂cO ₃, LiOHH ₂o, LiOH, Li ₂o or CH ₃cOOLi2H ₂the mixture of one or more in O.

6. the preparation method of lithium ion battery anode material nickel LiMn2O4 according to claim 1, is characterized in that: while preparing lithium ion battery anode material nickel LiMn2O4, cool to the furnace to grind to sieve after room temperature and make nickel LiMn2O4 product.