A kind of preparation method of high-performance porous co-mn-o nano sheet material and its obtained material and application

Abstract

The invention discloses a preparation method for a high-performance porous Co-Mn-O nanosheet material as well as the material obtained by the preparation method and an application of the Co-Mn-O nanosheet material. The porous Co-Mn-O nanosheet with a controllable thickness and size is prepared in one step by using a synthetic method induced by a surfactant, taking an amphiphilic block copolymer asthe surfactant and a pore forming agent, taking water, ethanol and ethylene glycol as solvent phases, and adopting a high-temperature and high-pressure solvent thermal reaction. The porous Co-Mn-O nanosheet can be used as a negative electrode material to be used in a lithium ion battery and has excellent performance. The porous two-dimensional Co-Mn-O nanosheet is designed according to the characteristics in charge-discharge cycles of the negative electrode material of the lithium battery, thus problems such as remarkable volume effects and poor conductivity in a negative electrode material of a lithium battery are fully solved, and the electrochemical performance of the electrode material is greatly modified; and the preparation raw materials are cheap, the operation process is simple, the yield is high, the charge-discharge performance and the speed of the material are excellent, and the porous Co-Mn-O nanosheet is convenient for industrialized production.

Description

technical field

[0001] The invention relates to the technical field of negative electrode materials for lithium ion batteries, in particular to the preparation and application of a high-performance porous Co-Mn-O nanosheet. Background technique

[0002] Rechargeable lithium-ion batteries are currently one of the most promising energy storage devices. In recent decades, a great deal of research has been carried out on the improvement of cathode materials for lithium-ion batteries. Among these anode materials, 3d transition metal oxides (iron, cobalt, nickel, and copper oxides) have been extensively studied. In particular, cobalt oxide is an important transition metal oxide attractive for its high theoretical capacity (890mAh g -1 broad interests). However, its poor cycle stability and rate capability are mainly attributed to the huge volume effect and severe particle agglomeration during Li-ion deintercalation.

[0003] Cobalt exhibits a higher oxidation potential than ma...

Examples

Embodiment 1

[0032] 1) Prepare a mixed solution with 13mL absolute ethanol, 13mL ethylene glycol and 1ml water.

[0033] 2) Add 0.2g P-123 to the above mixed solution, and dissolve it evenly by ultrasonic;

[0034] 3) Add 0.0921g C 4 h 6 MnO 4 4H 2 O and 0.09375g C 4 h 6 CoO 4 4H 2 O is dispersed in the above mixed solution (cobalt acetate: manganese acetate molar ratio is 1 / 1), after ultrasonic dissolution is complete, aging for 72h;

[0035] 4) Put the above-mentioned aged solution into a 50mL polytetrafluoroethylene substrate, and put it on the shell of a stainless steel reaction kettle for hydrothermal reaction at 170°C for 5h.

[0036] 5) After collecting, washing and vacuum-drying the material after the hydrothermal reaction, the powder was sintered in a muffle furnace at 600 ° C for 5 h to obtain a black powder, which is a porous Co-Mn-O nanosheet (denoted as Co-Mn -O-1);

[0037]6) Fully grind the dried composite material as the lithium ion electrode negative electrode ma...

Embodiment 2

[0039] Same operation as Example 1, except that the cobalt acetate: the manganese acetate mol ratio is 2 / 1). (Denoted as Co-Mn-O-2)

[0040] Adopt TEM to characterize the morphology of the prepared sample in this embodiment, as Figure 4 shown. The Si nanoparticles are evenly and effectively covered by the carbon coating.

Embodiment 3

[0042] Same operation as Example 1, except that cobalt acetate: manganese acetate mol ratio is 4 / 1). (Denoted as Co-Mn-O-4).

technical field

[0001] The invention relates to the technical field of negative electrode materials for lithium ion batteries, in particular to the preparation and application of a high-performance porous Co-Mn-O nanosheet. Background technique

[0002] Rechargeable lithium-ion batteries are currently one of the most promising energy storage devices. In recent decades, a great deal of research has been carried out on the improvement of cathode materials for lithium-ion batteries. Among these anode materials, 3d transition metal oxides (iron, cobalt, nickel, and copper oxides) have been extensively studied. In particular, cobalt oxide is an important transition metal oxide attractive for its high theoretical capacity (890mAh g -1 broad interests). However, its poor cycle stability and rate capability are mainly attributed to the huge volume effect and severe particle agglomeration during Li-ion deintercalation.

[0003] Cobalt exhibits a higher oxidation potential than ma...

Examples

Embodiment 1

[0032] 1) Prepare a mixed solution with 13mL absolute ethanol, 13mL ethylene glycol and 1ml water.

[0033] 2) Add 0.2g P-123 to the above mixed solution, and dissolve it evenly by ultrasonic;

[0034] 3) Add 0.0921g C 4 h 6 MnO 4 4H 2 O and 0.09375g C 4 h 6 CoO 4 4H 2 O is dispersed in the above mixed solution (cobalt acetate: manganese acetate molar ratio is 1 / 1), after ultrasonic dissolution is complete, aging for 72h;

[0035] 4) Put the above-mentioned aged solution into a 50mL polytetrafluoroethylene substrate, and put it on the shell of a stainless steel reaction kettle for hydrothermal reaction at 170°C for 5h.

[0036] 5) After collecting, washing and vacuum-drying the material after the hydrothermal reaction, the powder was sintered in a muffle furnace at 600 ° C for 5 h to obtain a black powder, which is a porous Co-Mn-O nanosheet (denoted as Co-Mn -O-1);

[0037]6) Fully grind the dried composite material as the lithium ion electrode negative electrode ma...

Embodiment 2

[0039] Same operation as Example 1, except that the cobalt acetate: the manganese acetate mol ratio is 2 / 1). (Denoted as Co-Mn-O-2)

[0040] Adopt TEM to characterize the morphology of the prepared sample in this embodiment, as Figure 4 shown. The Si nanoparticles are evenly and effectively covered by the carbon coating.

Embodiment 3

[0042] Same operation as Example 1, except that cobalt acetate: manganese acetate mol ratio is 4 / 1). (Denoted as Co-Mn-O-4).

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