摘要
本文研究了以碳包覆磷酸钛钠[NaTi_2(PO_4)_3/C]为负极、活性炭(AC)为正极的超级电容器.以柠檬酸为碳源,采用液相法制备前驱物,利用高温固相反应制备得到NaTi_2(PO_4)_3/C纳米颗粒.正负极活性物质质量比值为2.2,组装NaTi_2(PO_4)_3/C//Na_2SO_4//AC钠离子基水系混合超级电容器.电化学性能测试表明,在电压范围0.15~1.4 V,电流密度为0.5 A·g^(-1)的条件下,该电容器的比功率为121.15 W·kg^(-1),比能量为18.71 Wh·kg^(-1).提升电流密度至10 A·g^(-1),比功率可达2.42 kW·kg^(-1),相应比能量为14.13 Wh·kg^(-1).在1 A·g^(-1)的电流密度下,循环1000圈,该电容器的比容量仍保持在初始值的76%.该器件很有希望作为高功率的辅助能量储存设备实现应用.
Supercapacitors have been regarded as one of the next-generation energy storage devices because of the high power density, excellent cycling performance, long lifespan and easy maintenance. However, its relatively low specific energy hinders its application in the future. Recently, Na-ion based aqueous hybrid supercapacitors have attracted worldwide attention due to its high energy density, environment friendly and low cost. In our work, the Na-ion aqueous hybrid supercapacitor is constructed with NaTi2（PO4）3/C and commercial activated carbon as electrode materials. NaTi2（PO4）3/C nanoparticles with the size of about 40 nm were synthesized by high-temperature solid state reaction method using the NaTi2（PO4）3/C precursor that was prepared through the solution method with Ti（C4H9O）4, NH4H2PO4, Na2CO3 as the raw materials, and citric acid as the carbon source. The electrochemical tests were performed using 1 mol·L-1 Na2SO4 solution as the electroiyte. The carbon-coated NaTi2（PO4）3 electrode delivers the discharge capacity of 122 mAh·g-1 and shows an excellent cycling stability with the retention of 60% of the initial capacity after 1000 cycles at a 10C rate. The supercapacitor was consisted of NaTi2（PO4）3/C anode, AC cathode and 1 mol·L-1 Na2SO4 electrolyte. And the weight ratio of active materials in cathode and anode was 2.2. Cyclic voltammetry, galvanostatic test were employed to study the electrochemical properties of the supercapacitor. The as-fabricated device was then cycled between 0.15 - 1.4 V with different current density. Our results show the power density of 121.15 W·kg-1 with specific energy of 18.71 Wh ·kg-1 at the current density of 0.5 A·g-1. Moreover, the specific energy and power density goes to 14.13 Wh·kg-1 and 2.42 kW·kg-1 at a higher current density of 10 A·g-1. More importantly, the device showed an excellent cycling stability with the retention of 76% after 1000 cycles at a current density of 1 A·g-1. This research shows the designed hybrid supercapacitor has the potential to be used as auxiliary high-power energy storage device for the practical applications.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2017年第2期241-246,共6页
Acta Chimica Sinica
基金
国家重点基础研究项目(2014CB932302)
国家自然科学基金(21673116,21403107,21373111)
江苏省自然科学基金(BK20160068,BK20140055)
江苏省高校优势学科建设项目
江苏省产学研联合项目(BY2015069-01)资助~~
关键词
水溶液
钠离子
混合型超级电容器
磷酸钛钠
活性炭
aqueous electrolyte
sodium-ion
hybrid supercapacitor
NaTi2（PO4）3
activated carbon
