Lithium-ion battery negative electrode material ca9co12o28 with layered structure and preparation method thereof

Abstract

The invention discloses a layered structured negative electrode material Ca9Co12O28 of a lithium ion battery and a preparation method of the layered structure negative electrode material, relating to the field of the lithium ion battery. The method comprises the following steps of mixing and dissolving 1 part of calcium source, 1-2 parts of cobalt sources and 0.005-0.01 part of surfactant in water according to the mole part, and enabling the mixture to react for 1.5-3 hours at 35-45 DEG C; adding 4-5 parts of weak acid, rising a temperature to 47-55 DEG C for reaction for 1.5-3 hours, adding 18-20 parts of polyalcohol, rising the temperature to 70-85 DEG C for reaction for 1.5-3 hours, and carrying out reduced pressure distillation to remove moisture; and carrying out reaction for 3-5 hours at 140-160 DEG C, and calcining resin for 3-5 hours at 800-900 DEG C. The Ca9Co12O28 is of a layered structure, the grain size is 0.5-1.2 micrometers, and the discharging specific capacity is maintained at 236mAh g<-1> after the Ca9Co12O28 is charged and discharged for 200 times in a condition that the current density is 1,800-2,000mAh g<-1>. The Ca9Co12O28 disclosed by the invention is uniform in size, the rate performance of the electrode material can be improved, and rapid charging and discharging is achieved.

Description

technical field [0001] The invention relates to the field of lithium batteries, in particular to a layered lithium ion battery negative electrode material Ca 9 co 12 o 28 and its preparation method. Background technique [0002] Since traditional fossil fuels are non-renewable energy sources with limited storage capacity and pollute the environment during use, they cannot meet the energy needs of human development. Therefore, new clean, green, environmentally friendly, and renewable energy sources are allowed to be developed as alternative energy sources. [0003] Lithium-ion batteries (hereinafter referred to as lithium batteries) have rapidly become the main research and development focus of rechargeable power supplies for portable electronic products due to their light weight, high specific energy, long cycle life, and environmental protection. [0004] Existing lithium batteries usually use carbon materials as negative electrode materials, and the theoretical capacity...

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Problems solved by technology

[0007] Ca 9 co 12 o 28 It is usually synthesized by high-temperature solid-solid reaction method, co-precipitation method or Pechini (polymer precursor method). High-temperature solid-solid reaction method and co-precipitation method cannot control the product morphology and grain size, and long-term high-temperature calcination will lead to The product particles agglomerate to form irregular micron-scale products; although the Pechini method can obtain nanoparticles with uniform particle size and effectively shorten the lithium ion diffusion path, the obtained Ca 9 co 12 o 28 Particles are too small, increasing the Ca 9 co 12 o 28 The contact area with the electrolyte leads to the formation of a large-area solid electrolyte interface film, which consumes part of the lithium ions, increases the irreversible capacity of the first charge and discharge, and reduces the charge and discharge efficiency of the electrode material; It is easy to dissolve in the electrolyte, so that the capacity of the battery decays rapidly during the charging and discharging process

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