Fabrication and performance evaluation of rare earth lanthanum sulfide film for supercapacitor application: Effect of air annealing

In this work, the electrochemical properties of rare earth lanthanum sulfide (La2S3) films obtained by chemical bath deposition method are investigated as an electrode material for supercapacitor application. The effect of air annealing on structural, surface morphological and wettability properties of La2S3 films is studied. The X-ray diffraction and FT-Raman analysis confirm the formation La2S3 film. A porous spongy network of La2S3 film reveals the hydrophilic nature. The supercapacitive properties of La2S3 electrode are evaluated using cyclic voltammetry and galvanostatic charge–discharge mode. The maximum specific capacitance of 294Fg−1 is achieved for air-annealed La2S3 electrode at a scan rate of 5mVs−1 with 89% electrochemical cyclic stability over 1000cycles. The spongy network of air-annealed La2S3 film enhances the supercapacitive performance. The auspicious properties of La2S3 electrode are effective for the fabrication of flexible La2S3/LiClO4-PVA/La2S3 solid-state supercapacitor device. The specific capacitance of supercapacitor device with diverse bending angles and cyclic stability is examined. [Display omitted] •Spongy network of La2S3 film is prepared by simple, inexpensive, chemical bath deposition method.•The supercapacitive performance of air-annealed La2S3 is higher than that of as-deposited electrode.•The flexible lightweight supercapacitor exhibits good electrochemical performance.