Carbon-coated porous manganese monoxide composite material and preparation method and application thereof

Abstract

The invention discloses a carbon-coated porous manganese monoxide core-shell structure composite material and a preparation method and an application thereof. The preparation method comprises the following steps: firstly, with styrene as a carbon source and potassium peroxodisulfate as an initiator, carrying out soap-free emulsion polymerization to obtain a polystyrene microsphere template, and then carrying out surface modification on microspheres with concentrated sulfuric acid; with common manganese sulfate as a manganese source, preparing manganese carbonate particles embedded with a plurality of polystyrene microspheres by a liquid phase deposition method, and then adding a shell layer material to coat the particle surfaces with a carbon layer; and finally, carrying out high-temperature carbonization to obtain a novel carbon-coated porous manganese monoxide core-shell structure composite material. The composite material is spherical particles with uneven surfaces; and the spherical particles comprise manganese monoxide grains, multi-scale holes and the carbon layer. The special structure with the carbon layer and the multi-scale holes can play a role in buffering volume expansion of manganese monoxide in the repeated charging and discharging processes. The composite material disclosed by the invention has excellent cycling stability and rate capability as an anode material for a lithium-ion battery.

Description

technical field [0001] The invention relates to a preparation method of a novel carbon-coated porous manganese monoxide core-shell structure composite material and its application as a lithium-ion battery negative electrode material. Background technique [0002] Since the commercialization of lithium-ion batteries in the 1990s, lithium-ion batteries have occupied an important position in the electronic commodity market. Today, with the development of technology, various electronic products, such as mobile phones, notebook computers, digital cameras and tablet computers are increasingly miniaturized and lightweight. Therefore, new batteries with high efficiency and small size have become people's pursuit. In short, lithium-ion secondary batteries with high capacity, long life and fast charging and discharging have become a research hotspot for researchers. Electrode materials are one of the core components of lithium-ion batteries, which play a decisive role in battery per...

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Problems solved by technology

Such as MnO / Ccore–shellnanorodshighcapacityanodematerialsforlithium-ionbatteries MnO 2 Nanowires were used as precursors, and MnO / C core-shell nanorods were prepared by in situ reduction method with F127 as carbon source. -1 The secondary cycle capacity is 800mAhg at the current density -1 , compared to MnO 2 The nanowire is greatly improved, but the loss is faster, and the specific capacity is only 75% after 40 cycles

The literature Green and facilefabrication of hollow porous MnO / C microspheres from microalgaes for lithium-ion batteries prepared a kind of hollow porous MnO / C microspheres by biological template method. -1 The reversible specific capacity reaches 700mAhg under the current density -1 , after 50 cycles, the specific capacity maintains 94% of the initial value, and the rate performance has also improved, but the first charge and discharge efficiency is below 80%, and the capacity needs to be further improved

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