Method for preparing silicon-carbon negative electrode of lithium battery through mechanical compounding without firing

Abstract

The invention provides a method for preparing a silicon-carbon negative electrode of a lithium battery through mechanical compounding without firing and a product thereof. The method comprises the following steps: ball-milling silicon powder and carbon powder; then subjecting the treated silicon powder and carbon powder to mixing and ball-milling with raw materials such as SBR styrene-butadiene latex, silicate minerals and a conductive filler to form a slurry mixture; mixing the slurry mixture with a surfactant to form composite slurry coated with silicon-carbon mixed powder; sufficiently impregnating the obtained composite slurry with conductive foamed plastic; and finally, curing the composite slurry at room temperature to form a carrier-loaded silicon / carbon negative pole piece with a foam structure. The method can realize curing at normal temperature; preparation process is simple; a physical confinement can be formed for the silicon-carbon negative electrode material; and the compounding capacity of silicon / carbon powder is improved. In addition, a certain amount of the styrene-butadiene latex is doped into the composite slurry, so an active material and a conductive agent canbe uniformly embedded into the foamed plastic, and a conductive channel is fully and effectively formed; and the specific surface area of the negative electrode material is large, an electrolyte andthe negative electrode material can be fully infiltrated, and the cycle performance of the battery is effectively improved.

Description

technical field [0001] The invention relates to the field of lithium batteries, in particular to a method for preparing a silicon-carbon negative electrode of a lithium battery. Background technique [0002] In recent years, the wide application of lithium-ion batteries in mobile phones, notebook computers, new energy vehicles, and energy storage has put forward higher requirements for lithium-ion batteries, requiring higher energy density, better cycle life, and more Good high and low temperature charge and discharge performance and safety performance, etc., which require the positive and negative electrode materials for lithium-ion batteries to be further developed and improved. The main components of lithium-ion batteries are positive electrodes, negative electrodes, electrolytes, separators, and packaging components. Among them, the most mature application of commercial anode is graphite anode, whose theoretical specific energy is 372mAh / g, but it has been developed clo...

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Problems solved by technology

[0004] Aiming at the problems that the existing silicon-carbon anode materials have complex procedures and poor electrolyte infiltration effect, the present invention proposes a method for preparing silicon-carbon anodes of lithium batteries by mechanical compounding without firing. solidification, the preparation process is simple, and does not need to be sintered at high temperature. In addition, a certain amount of styrene-butadiene latex is mixed into the composite slurry, and the uniformly dispersed styrene-butadiene latex emulsion droplets are easy to combine with silicate minerals, conductive additives, and nano silicon The styrene-butadiene latex emulsion particles carrying powder materials have good compatibility with porous conductive foam plastics, and can make active materials and conductive agents evenly embedded in foam plastics, fully and effectively Form a conductive channel, and the specific surface area of ​​the negative electrode material is large, the electrolyte can fully infiltrate the negative electrode material, and the cycle performance of the battery is effectively improved

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