CN-121698389-B - Glassy indium yttrium oxide modified ternary layered oxide positive electrode material and preparation method thereof

CN121698389BCN 121698389 BCN121698389 BCN 121698389BCN-121698389-B

Abstract

The invention discloses a glassy indium yttrium oxide modified ternary layered oxide positive electrode material and a preparation method thereof, wherein the preparation method comprises the steps of (1) mixing and grinding N-vinylamide polymer, indium acetate, yttrium acetate and ternary layered oxide positive electrode material to form uniform mixed powder; the method comprises the steps of (1) mixing mixed powder with ultrapure water to form suspension, performing ultrasonic dispersion, (3) heating and evaporating a sample after ultrasonic dispersion, (4) sintering the sample after evaporation, naturally cooling to room temperature after sintering to obtain a sintered product, and (5) grinding, washing and drying the sintered product, and grinding and sieving again to obtain a final product. The core structure of the obtained anode material is ternary layered oxide anode material, and the outer layer is a glassy indium yttrium oxide coating layer obtained by in-situ derivatization. The method improves the problems of capacity stability and voltage attenuation in the cycling process of the ternary layered oxide positive electrode material, improves the multiplying power performance of the material, and is suitable for large-scale production.

Inventors

CHEN YUFANG
Du Yanshuo
LU DI
XIAO PEITAO
SHI XIANXIAN
ZHENG CHUNMAN
Teng tao
ZHANG XIAO
WANG JINHUI

Assignees

中国人民解放军国防科技大学

Dates

Publication Date: 20260508
Application Date: 20260212

Claims (7)

1. The preparation method of the glassy indium yttrium oxide modified ternary layered oxide positive electrode material is characterized by comprising the following steps of: (1) Mixing and grinding N-vinylamide polymer, indium acetate, yttrium acetate and ternary layered oxide anode material to form uniform mixed powder, wherein the N-vinylamide polymer is polyvinylpyrrolidone or polyvinylcaprolactam, and the mass ratio of the N-vinylamide polymer to the indium acetate to the yttrium acetate to the ternary layered oxide anode material is 0.01-0.02:0.009-0.018:0.001-0.002:1; (2) Mixing the mixed powder with ultrapure water to form suspension, and then performing ultrasonic dispersion; (3) Heating and evaporating the sample after ultrasonic dispersion; (4) Sintering the evaporated sample, and naturally cooling to room temperature after sintering to obtain a sintered product, wherein the temperature rising rate of sintering is 1-15 ℃ per minute, the sintering temperature is 500 ℃, and the sintering time is 5 hours; (5) Grinding, washing and drying the sintered product, and grinding and sieving again to obtain the final product.
2. The method for preparing the glassy indium yttrium oxide modified ternary layered oxide positive electrode material according to claim 1, wherein the positive electrode material is a lithium-rich manganese-based or high-nickel ternary positive electrode material.
3. The preparation method of the glassy indium yttrium oxide modified ternary layered oxide positive electrode material according to claim 1, wherein the step (3) is characterized in that a sample after ultrasonic dispersion is added into a split flask and then is installed on a heating device for heating and evaporation, and the heating device is one of water bath heating, heating jacket heating, magnetic stirring heating and rotary evaporator heating devices.
4. The method for preparing a glassy indium yttrium oxide modified ternary layered oxide positive electrode material according to claim 3, wherein in the step (3), the evaporation condition is that the temperature is 100-150 ℃, and the rotation speed is 10-60 r/min.
5. The method for preparing a glassy indium yttrium oxide modified ternary layered oxide positive electrode material according to claim 1, wherein in the step (5), the drying temperature is 60 ℃, and the drying time is 1-6 h.
6. A glassy indium yttrium oxide modified ternary layered oxide positive electrode material, characterized in that it is prepared by the preparation method according to any one of claims 1 to 5.
7. The glassy indium yttrium oxide modified ternary layered oxide cathode material according to claim 6, wherein the glassy indium yttrium oxide modified ternary layered oxide cathode material has a core structure of a ternary layered oxide cathode material and an outer layer of a glassy indium yttrium oxide coating layer obtained by in-situ derivatization.

Description

Glassy indium yttrium oxide modified ternary layered oxide positive electrode material and preparation method thereof Technical Field The invention relates to the technical field of preparation of lithium ion battery anode materials, in particular to a glassy indium yttrium oxide modified ternary layered oxide anode material and a preparation method thereof. Background Lithium ion secondary batteries are important in the fields of consumer electronics and power batteries because of high energy density, portability and stability, but the actual energy density is generally between 300Wh/kg and 400Wh/kg, and is mainly limited by the development of anode and cathode materials, wherein the problems of lower capacity and energy density of the anode materials are particularly prominent, and become key factors for limiting the development of batteries. Although the positive electrode material systems such as the practical lithium cobalt oxide and lithium iron phosphate have been widely applied, the capacity of the positive electrode material system still cannot meet the requirements, ternary oxide positive electrode materials with specific capacities of up to 200mAh/g to 300mAh/g and higher working voltages are widely concerned, the realization of ultra-high energy density is expected to break through the existing bottleneck, however, the problems of oxygen loss, irreversible crystal phase conversion, transition metal ion dissolution, electrolyte decomposition, gas evolution and the like are faced in the charging and discharging process, poor circulation capacity and voltage stability are caused, and simultaneously, the multiplying power performance and coulombic efficiency are lower, so that the practical application is severely restricted. To improve stability, researchers have performed a number of doping and cladding modifications, for example, lun et al found that fluorine doping can suppress Jahn-Teller distortion of Mn 3+, promote orbital rearrangement and increase redox participation of manganese, thereby improving overall capacity, guo et al co-doped fluorine and aluminum to make the material reach a capacity of 217 mAh g -1 at 0.5C rate, a capacity retention rate of 88.21% after 150 cycles, and a specific capacity of 157 mAh g -1 at 10C. Heterostructure coating is also a common method, ma et Al construct a highly uniform AlPO 4 coating on the surface of a material by utilizing the chemical conversion of Al 3+ in phosphate buffer solution, so that the material obtains 282.1 mAh g -1 discharge specific capacity at 30 mA g -1 current density, and in 2018, a 14 nm thick Li 4Mn5O12 spinel coating constructed by Zhang et Al effectively reduces the activation and oxygen loss of the material above 4.5V after the first charge, improves coulomb efficiency, remarkably improves cycle stability and rate capability, and ensures that the capacity retention rate of the material after 300 cycles at 0.1C rate reaches 83.1%. However, the single doping or cladding modification effect is limited, and it is difficult to solve the difference of the structure and the performance attenuation mechanism driven by the different structural characteristics of the surface and the bulk of the material, so that the material still has a performance short plate under the actual working condition, and a certain distance is still provided for completely meeting the application requirements. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide the glassy indium yttrium oxide modified ternary layered oxide positive electrode material with excellent electrochemical performance and cycle stability and the preparation method thereof. In order to solve the technical problems, the technical scheme provided by the invention is that the preparation method of the glassy indium yttrium oxide modified ternary layered oxide positive electrode material comprises the following steps: (1) Mixing and grinding N-vinylamide polymer, indium acetate, yttrium acetate and ternary layered oxide anode material to form uniform mixed powder; (2) Mixing the mixed powder with ultrapure water to form suspension, and then performing ultrasonic dispersion; (3) Heating and evaporating the sample after ultrasonic dispersion; (4) Sintering the evaporated sample, and naturally cooling to room temperature after sintering to obtain a sintered product; (5) Grinding, washing and drying the sintered product, and grinding and sieving again to obtain the final product. In the preparation method of the glassy indium yttrium oxide modified ternary layered oxide positive electrode material, preferably, in the step (1), the N-vinylamide polymer is polyvinylpyrrolidone or polyvinylcaprolactam. In the preparation method of the glassy indium yttrium oxide modified ternary layered oxide cathode material, preferably, in the step (1), the mass ratio of the N-vinylamide polymer to the indium acetate to the yttrium acetate to the ternary layered o