Na Lei,Yin Qiao,Guanfu Liu,Renhao Xu,Guohua Jiang,Muslum Demir,Pianpian Ma
Cobalt-based perovskite SrCo 0.875 Nb 0.125 O 3 is an advantageous electrode material for supercapacitors . However, the particle form of SrCo 0.875 Nb 0.125 O 3 is not conducive to the electrochemical behavior. Based on this, surface MnO 2 modified SrCo 0.875 Nb 0.125 O 3 on carbon cloth (MnO 2 @SrCo 0.875 Nb 0.125 O 3 @CC) has been prepared as supercapacitor electrode. The dandelion-like morphology of MnO 2 significantly increases the specific surface area and inhibits the grain agglomeration of SrCo 0.875 Nb 0.125 O 3 , thus promoting the ion diffusion during the electrochemical process. As a result, the electrochemical performance of the composite is significantly optimized due to the synergistic effect of SrCo 0.875 Nb 0.125 O 3 and MnO 2 . The MnO 2 @SrCo 0.875 Nb 0.125 O 3 @CC electrode yields an ultra-high specific capacitance of 2066.0 mF cm −2 at 2 mA cm −2 current density. Compared with SrCo 0.875 Nb 0.125 O 3 @CC electrode and MnO 2 @CC electrode, this work provides a much improved performance. Besides, an asymmetric supercapacitor composed of MnO 2 @ SrCo 0.875 Nb 0.125 O 3 @CC as positive electrode and CuS@CC as negative electrode exhibits a voltage window of 1.8 V and a specific capacitance of 114.6 mF cm −2 when the current density is 3 mA cm −2 . A high energy density of 51.57 μ Wh cm −2 is achieved at a power density of 4.86 mW cm −2 for the device.
Na Lei,Pianpian Ma,Bo Yu,Shuhong Li,Jianming Dai,Guohua Jiang
The perovskite-type SrMn 0.875 Nb 0.125 O 3 (SMN) and SrCo 0.875 Nb 0.125 O 3 (SCN) materials are prepared through the solid-state reaction method as novel oxygen-intercalated electrode materials for supercapacitor . The crystal structure, powder morphology, and electrochemical performance have been characterized in detail. SMN exhibits a six-layer hexagonal (6 H ) structure with space group P 6 3 / mmc , while SCN shows the tetragonal structure of space group P 4/ mmm . Under the three-electrode system with 1 M Na 2 SO 4 neutral electrolyte solution, the specific capacitance ( C s ) of SCN can reach 894 mF cm −2 at 1 mA cm −2 , which is 4.7 times the value of SMN at the same condition. For SCN, the superiority of electrochemical performance is attributed to its porous surface morphology , perovskite structure with shorter B O bond length and large B-O-B bond angle, and a higher oxygen vacancy content. When combined with activated carbon (AC) electrode, the SCN//AC asymmetric supercapacitor with a working voltage of 2.0 V presents a specific energy density of 82.33 μWh cm −2 , while maintaining prominent cycling stability with a capacity retention of 88.88% after 10,000 cycles.
危险品化学品经营许可证（带存储）