A High-Efficiency Energy Storage Scheme of Solar Micro-Power Systems

Abstract

In self-power sensor nodes, the capability of energy harvesting and storing of the solar micro-power system determines their lifetime and adaptability to the environment. As a load of solar cells, energy storage devices directly influence the output conversion efficiency of solar cells and output power of solar micro-power system. In this paper, the advantages and disadvantages of NiCD batteries, NiMH batteries, Polymer Lithium-ion batteries and Super-capacitors are analyzed based on features of the solar micro-power system. A hybrid storage system combined with Polymer Lithium-ion batteries and the super-capacitors is designed. Experimental results show that the power density of hybrid storage system is larger than that of Polymer Lithium-ion batteries. The capability of pulsing load is improved over 60%, and the energy storage loss is reduced.