A lithium-rich/3d graphene composite cathode material

Abstract

The invention relates to a high-capacity lithium-rich / 3D graphene composite cathode material, the molecular formula of which is Li1+x[Mn1-y-z(CoyNiz?)]1-xO2 / 3D graphene, wherein, 0.02≤x≤0.6, 0< y<1, 0<z<1, and 0<1-y-z<1. During the preparation, the mixed solution of transition metal, urea and high boiling point solvent is prepared, and it is added into the uniformly dispersed graphene oxide or 3D graphene solution, and the precursor is obtained by reflux at a high temperature of 95-200 °C, and then the precursor It can be obtained by mixing with lithium salt in appropriate proportion, and going through high-temperature solid state. The positive electrode material has a small and uniform particle size, uniform element distribution, high electrochemical activity, good cycle performance and high rate electrochemical performance, and excellent comprehensive performance.

Description

technical field

[0001] The invention belongs to the field of electrochemistry, and in particular relates to a high-capacity lithium-rich / 3D graphene composite positive electrode material suitable for lithium-ion batteries. Background technique

[0002] At present, lithium-ion batteries have been widely used in various digital electronic devices, and have broad application prospects in the fields of electric vehicles and energy storage power stations in the future. People have put forward higher and higher requirements for the next generation of high-performance lithium-ion batteries, which can be summarized as "three highs and two lows": high energy density, high power characteristics, high safety performance, low cost, and low pollution. In terms of cathode materials, there are layered LiMO 2 (M=Mn, Ni, Co), such as LiCoO 2 、LiNi 0.33 mn 0.33 co 0.33 o 2 The discharge specific capacity is only 140~170mAh·g -1 , while spinel LiMn 2 o 4 and olivine LiFeP 4 The theor...

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