碳微球负载CuO纳米片用作锂离子电池的高性能负极材料

CuO nanosheets embedded on carbon microspheres as high-performance anode material in lithium-ion batteries

氧化铜(CuO)具有高理论容量、丰富的资源以及生态友好等特点,被认为是一种理想的锂离子电池负极材料.然而,由于CuO本身的低导电性和循环时巨大的体积膨胀,它在电池应用中的容量利用率和循环稳定性仍然存在不足.本工作中,我们通过在甲壳素衍生的碳微球的内外壁上直接原位合成CuO纳米片,构造出一种三维多孔碳@CuO复合材料.得益于碳微球的三维多孔导电框架和CuO纳米片的合理分布,CuO的容量利用率和结构稳定性在充电/放电过程中得到明显改善,所制备的电极具有优越的循环稳定性和出色的可逆容量.本工作为合理设计三维碳/过渡金属氧化物杂化体并用作电池负极材料提供了新的思路.

Because of its high capacity,availability,and environmental friendliness,copper oxide(CuO)is a desirable anode material for lithium-ion batteries(LIBs).However,due to low intrinsic electrical conductivity and enormous volume expansion during cycling,the capacity utilization and cycle stability of the CuO anode remain insufficient for battery applications.In this study,we design and fabricate a threedimensional(3D)porous carbon@CuO composite(C@CuO)by in situ synthesis of CuO nanosheets directly on the internal and external walls of chitin-derived carbon microspheres.Benefiting from the hierarchical conductive framework of the carbon microspheres and a rational distribution of CuO nanosheets,the capacity utilization and structural stability of the CuO nanosheets are substantially improved during the charge/discharge process.Thus,the C@CuO microspheres as the anode material for LIBs demonstrate a high reversible capacity of 626 mA h g−1 at 100 mA g−1 with a capacity retention of~93%over 200 cycles,a stable specific capacity of 553 mA h g−1 after 600 cycles even at a high current density of 1000 mA g−1,and superior rate capability with a high discharge capacity of 262 mA h g−1 at 5000 mA g−1.Therefore,this study innovatively constructs carbon microspheres with a hierarchical structure accompanied by self-growing CuO nanosheets as the anode material for LIBs,which may provide a new idea for the rational design of 3D carbon/metal oxide hybrids.