Aluminum-doped spinel manganese-based material and preparation method thereof

Abstract

The invention discloses an aluminum-doped spinel manganese-based material and a preparation method thereof. The method comprises the steps of respectively putting configured manganese source compound solution, or a nickel source compound, aluminum salt compound solution and a precipitator solution into a reactor according to the flow rate being 0.5-2L / h, stirring to control the pH value of a system to be 7-8.5 and the heating temperature of the system to be 30 DEG C-60 DEG C, heating and then curing for 10h-20h to obtain a spherical precipitate precursor, washing and drying the spherical precipitate precursor; forging the dried precipitate for 5-20h under the temperature being 600-900 DEG C; and sufficiently mixing oxidizing materials and a lithium source compound according to a proportion that the stoichiometric ratio exceeds the lithium source compound by 1-10%, and forging for 5-20h under the temperature being 600-900 DEG C to obtain the modified spinel manganese-based material. According to the method disclosed by the invention, the feature of the precursor and the distribution uniformity of an Al element can be improved effectively; due to the reasonable high forging temperature and doping proportion, the structure stability of the aluminum-doped spinel manganese-based material can be improved greatly, and the circulation performance and high-temperature and low-temperature performances of the material can be improved; and the process is simple, and the repeatability is good.

Description

technical field

[0001] The invention belongs to the field of lithium ion batteries, and relates to a lithium ion positive electrode material, in particular to a method for preparing an aluminum-doped spinel manganese-based material. Background technique

[0002] Li-Mn-O spinel manganese-based materials are considered to be positive electrode materials for lithium-ion batteries with good application prospects due to their three-dimensional lithium ion channels and stable thermodynamic properties. And its derived LiM x mn 2-x o 4 (M=Cr, Co, Fe, Ni, etc.) materials have a high-voltage platform above 4.5V and have higher energy density, which has also attracted widespread attention. Among them, Li-Ni-Mn-O spinel manganese-based materials have become a hot spot in the research of high-voltage materials due to their high discharge specific capacity due to their 4.7V voltage platform. However, spinel manganese-based materials such as Li-Mn-O and Li-Ni-Mn-O have certain limitati...

Examples

Embodiment 1

[0030] MnSO 4 ·H 2 O was dissolved in deionized water to make a 2mol / L solution. with anhydrous Na 2 CO 3 As a precipitating agent, it can be dissolved in deionized water to form a 2mol / L solution. Using a peristaltic pump, the MnSO 4 solution with Na 2 CO 3 The solution was poured into the reactor at a flow rate of 0.5mol / L. Weigh a certain amount of aluminum isopropoxide in proportion, dissolve aluminum isopropoxide and acetylacetone in ethanol according to the molar ratio of 1:1, the concentration is 0.8mol / L, and dissolve the above aluminum isopropoxide solution at a certain dropwise into the reactor. The pH of the control system is ≈8, the temperature of the system is 50°C, the stirring speed is 600r / min, and the (Mn 0.925 Al 0.075 )CO 3precipitation. After the precipitate was filtered and dried, it was calcined at 850 °C for 5 h to obtain M 2 o 3 (M=Mn, Al) oxide. After fully mixing the oxide and lithium carbonate with an amount of 1.05 times the stoichiom...

Embodiment 2

[0035] Weigh 0.1mol nickel sulfate and 0.3mol manganese sulfate according to the molar ratio of 1:3, and dissolve them in deionized water to prepare a mixed solution of 2mol / L. Weigh 0.4mol sodium carbonate and prepare a 2mol / L solution as a precipitant. The manganese sulfate solution, nickel sulfate solution and sodium carbonate solution were pumped into the reactor at a flow rate of 0.5 mol / L by a peristaltic pump. Weigh a certain amount of aluminum isopropoxide in proportion, dissolve aluminum isopropoxide and acetylacetone in ethanol according to the molar ratio of 1:1, the concentration is 0.8mol / L, and drop the aluminum salt solution at a certain speed added to the reactor. The pH value is controlled at 8.3, the temperature is 50°C, the stirring speed is 400r / min, and the reaction time is 20h. After several times of filtration, washing, and drying, a carbonate precipitate is obtained. The precipitate was heat-treated at 600°C for 5h to obtain the oxide. Fully grind th...

Embodiment 3

[0038] Dissolve manganese sulfate in deionized water to make a 1mol / L solution. Ammonium bicarbonate was used as a precipitating agent, dissolved in deionized water to form a 1mol / L solution. The manganese sulfate solution and the ammonium bicarbonate solution were pumped into the reactor at a flow rate of 0.5 mol / L by a peristaltic pump. Weigh a certain amount of aluminum isopropoxide in proportion, dissolve aluminum isopropoxide and acetylacetone in ethanol according to the molar ratio of 1:1, the concentration is 0.8mol / L, and drop the aluminum salt solution at a certain speed added to the reactor. The pH of the control system is ≈7.5, the temperature of the system is 50°C, the stirring speed is 600r / min, and the (Mn 0.925 Al 0.075 )CO 3 precipitation. After the precipitate was filtered and dried, it was calcined at 800 °C for 5 h to obtain M 2 o 3 (M=Mn, Al) oxide. After fully mixing the oxide and lithium carbonate with an amount of 1.01 times the stoichiometric ra...

technical field

[0001] The invention belongs to the field of lithium ion batteries, and relates to a lithium ion positive electrode material, in particular to a method for preparing an aluminum-doped spinel manganese-based material. Background technique

[0002] Li-Mn-O spinel manganese-based materials are considered to be positive electrode materials for lithium-ion batteries with good application prospects due to their three-dimensional lithium ion channels and stable thermodynamic properties. And its derived LiM x mn 2-x o 4 (M=Cr, Co, Fe, Ni, etc.) materials have a high-voltage platform above 4.5V and have higher energy density, which has also attracted widespread attention. Among them, Li-Ni-Mn-O spinel manganese-based materials have become a hot spot in the research of high-voltage materials due to their high discharge specific capacity due to their 4.7V voltage platform. However, spinel manganese-based materials such as Li-Mn-O and Li-Ni-Mn-O have certain limitati...

Examples

Embodiment 1

[0030] MnSO 4 ·H 2 O was dissolved in deionized water to make a 2mol / L solution. with anhydrous Na 2 CO 3 As a precipitating agent, it can be dissolved in deionized water to form a 2mol / L solution. Using a peristaltic pump, the MnSO 4 solution with Na 2 CO 3 The solution was poured into the reactor at a flow rate of 0.5mol / L. Weigh a certain amount of aluminum isopropoxide in proportion, dissolve aluminum isopropoxide and acetylacetone in ethanol according to the molar ratio of 1:1, the concentration is 0.8mol / L, and dissolve the above aluminum isopropoxide solution at a certain dropwise into the reactor. The pH of the control system is ≈8, the temperature of the system is 50°C, the stirring speed is 600r / min, and the (Mn 0.925 Al 0.075 )CO 3precipitation. After the precipitate was filtered and dried, it was calcined at 850 °C for 5 h to obtain M 2 o 3 (M=Mn, Al) oxide. After fully mixing the oxide and lithium carbonate with an amount of 1.05 times the stoichiom...

Embodiment 2

[0035] Weigh 0.1mol nickel sulfate and 0.3mol manganese sulfate according to the molar ratio of 1:3, and dissolve them in deionized water to prepare a mixed solution of 2mol / L. Weigh 0.4mol sodium carbonate and prepare a 2mol / L solution as a precipitant. The manganese sulfate solution, nickel sulfate solution and sodium carbonate solution were pumped into the reactor at a flow rate of 0.5 mol / L by a peristaltic pump. Weigh a certain amount of aluminum isopropoxide in proportion, dissolve aluminum isopropoxide and acetylacetone in ethanol according to the molar ratio of 1:1, the concentration is 0.8mol / L, and drop the aluminum salt solution at a certain speed added to the reactor. The pH value is controlled at 8.3, the temperature is 50°C, the stirring speed is 400r / min, and the reaction time is 20h. After several times of filtration, washing, and drying, a carbonate precipitate is obtained. The precipitate was heat-treated at 600°C for 5h to obtain the oxide. Fully grind th...

Embodiment 3

[0038] Dissolve manganese sulfate in deionized water to make a 1mol / L solution. Ammonium bicarbonate was used as a precipitating agent, dissolved in deionized water to form a 1mol / L solution. The manganese sulfate solution and the ammonium bicarbonate solution were pumped into the reactor at a flow rate of 0.5 mol / L by a peristaltic pump. Weigh a certain amount of aluminum isopropoxide in proportion, dissolve aluminum isopropoxide and acetylacetone in ethanol according to the molar ratio of 1:1, the concentration is 0.8mol / L, and drop the aluminum salt solution at a certain speed added to the reactor. The pH of the control system is ≈7.5, the temperature of the system is 50°C, the stirring speed is 600r / min, and the (Mn 0.925 Al 0.075 )CO 3 precipitation. After the precipitate was filtered and dried, it was calcined at 800 °C for 5 h to obtain M 2 o 3 (M=Mn, Al) oxide. After fully mixing the oxide and lithium carbonate with an amount of 1.01 times the stoichiometric ra...

Images