用于光储一体化器件的低内阻电极材料研究

Research on low internal resistance electrode materials forintegrated photovoltaic-storage device

光储一体化器件能够将太阳能转化后直接以化学能的形式储存在储能材料中,实现对太阳能的直接利用。提升光储一体化器件的总能量转化效率是目前一大研究重点。研究制备了还原氧化石墨烯(rGO)原位负载氢氧化镍纳米颗粒低内阻复合材料用于超级电容器正极并组装光储一体化器件。该电极在2和20A/g的电流密度下放电比容量分别为1586.4和1108F/g,保持率高达70.0%。而未经负载的纯氢氧化镍电极在2和20A/g的电流密度下放电比容量分别为622.8和304F/g,保持率仅为48.8%。另外,在2A/g电流密度下,复合电极的库仑效率为96.5%,而纯氢氧化镍电极的库仑效率仅为48.4%。复合电极中的薄片状氢氧化镍纳米颗粒相较于纯氢氧化镍具备更大的电极-电解液界面,有利于电子、质子在界面处地快速交换;同时,复合电极中的rGO能够在充放电过程中迅速将电子导出,降低电极内阻。将复合电极材料用于光储一体化器件,获得高达14.21%的总能量转换效率。对光储器件中储能材料的设计提供新思路。

The integrated photovoltaic-storage device can convert solar energy into chemical energy for direct storage to achieve the direct use of solar energy.Improving the total energy conversion efficiency is a major research focus.A low internal resistance composite material that is in-situ grown nickel hydroxide nanosheets on reduced graphene oxide(rGO)was prepared for the cathode of supercapacitor and the integrated photovoltaic-storage device was assembled.The discharge specific capacitance of the composite electrode is 1586.4 F/g at 2 A/g and even 1108 F/g at 50 A/g,and the retention rate is as high as 70.0%.The discharge specific capacitance of the nickel hydroxide electrode is 622.8 F/g at 2 A/g and even 304 F/g at 50 A/g,and the retention rate is 48.8%.In addition,the coulombic efficiency of composite electrode is 96.5%,while that of nickel hydroxide electrode is only 48.4%at 2 A/g.Compared with the nickel hydroxide,the composite material has a larger electrode electrolyte interface,which is conducive to the rapid exchange of electrons and protons at the interface.Meanwhile,the electrons can be exported quickly in the charging-discharging process by rGO in electrode,which reduces the internal resistance of the device.The total energy conversion efficiency of 14.21%was obtained by using composite materials in integrated photovoltaic-storage device.It is expected to provide a new direction for the design of energy storage materials for the integrated photovoltaic-storage device.