Titanium doped niobium oxide for stable pseudocapacitive lithium ion storage and its application in 3 V non-aqueous supercapacitors

Developing high energy density supercapacitors is of great importance to the transportation, consumer eIectronics and micro-grid energy storage sectors. In this contribution, we introduce a titanium doping strategy to enhance the electrochemical performance of orthorhombic phase niobium oxide (T-Nb2O5). The Ti doping is abIe to provide an additionaI redox reaction and reduce the charge transfer resistance during the eIectrochemicaI reaction. As a resuIt, Ti doped T-Nb205 shows a pseudocapacitive Li+ storage capacity of 204.3 mA h g(-1) and a capacity retention of 88.8% after 1000 cycIes at 5C rate. Moreover, a non-aqueous supercapacitor prototype based on Ti doped T-Nb2O5 and poIyaniIine-singIe waII carbon nanotubes is fabricated. The 3 V prototype supercapacitor achieves an enhanced energy density of 110.3 Wh kg(-1) at 150 W kg(-1).