磷酸镁多孔材料的制备及其在结构超级电容器的应用

Preparation of porous magnesium phosphate material and its application in structural supercapacitors

以NaHCO_3为引气剂,利用化学发泡法制备磷酸镁多孔材料(MPCPM),该材料孔径发达、强度较高。利用MPCPM和KOH复合形成结构载体/电解质双连续相系统,并与石墨烯电极组装成一种新型结构超级电容器。研究发现,MPCPM孔隙连通度是影响结构超级电容器电学性能的主要因素。内部连通孔隙结构有利于离子的运输,从而改善结构超级电容器的储能容量。使用循环伏安、交流阻抗、恒流充放电以及抗压强度测试等方法研究化学发泡剂NaHCO_3掺量及养护龄期对结构超级电容器电学性能和力学性能的影响。NaHCO_3掺量为2.5%时比电容最高可达62.2 F·g^(-1),比不掺加NaHCO_3时提高了34.1%。并且当NaHCO_3掺量为2%其比电容为38.79 F·g^(-1),同时抗压强度高达18.76 MPa,显示出良好的多功能性。

The magnesium phosphate based porous material(MPCPM)was prepared by chemical foaming method using NaHCO3 as an air entraining agent.The MPCPM was characteristic of developed pore structure and high strength,hence it is possible to develop a multifunctional composite which is prepared by the MPCPM supportor and KOH electrolyte.The composite was sandwiched by two graphene electrodes,then a novel structural supercapacitor was fabricated.Experimental results show that electrochemical properties of the structural supercapacitor can be attributed to the pore connectivity of MPCPM.The MPCPM contains a great amount of connected pores which can provide paths for ion motion and ion storage.The effects of the NaHCO3 content and the curing age on the electrochemical and mechanical properties of the structural supercapacitor were analyzed.CV,EIS and CD analyses reveal that the structural supercapacitor exhibits ideal capacitive behavior and charge/discharge performance.The maximum specific capacitance is as high as 62.2 F·g?1 with the NaHCO3 content at 2.5%,it is increased by 34.1%compared with the MPCPM without addition of NaHCO3.Moreover,the structural supercapacitor exhibits a specific capacitance of 38.79 F·g?1 and a compressive strength of 18.76 MPa with the NaHCO3 content at 2%.It can achieve a balance between electrochemical performance and mechanical property.And this novel structural supercapacitor may have potential application in multifunctional civil engineering structures.