Scalable Synthesis of Ni3B2O6 Nanograins and Fabrication of a Coin Cell Supercapacitor for Powering Temperature Sensor Devices

• Published in: ACS applied electronic materials 2023-09, Vol.5 (9), p.5005-5016
• Main Authors: Somanath, Beena, C, Manjunatha, Athreya, Yash, KP, Shwetha, Abraham, Nelsa, Viswanathan, Suresh Babu, MK, Sudha Kamath, Kumar, S. Girish, Khosla, Ajit
• Format: Article
• Language: English
• ISSN: 2637-6113; 2637-6113
• DOI: 10.1021/acsaelm.3c00765

In this work, we present a facile and scalable method to synthesize nickel orthoborate nanograins (NBNG) by a simple solution combustion method. The expected crystallinity, phases, and functional groups of NBNG were confirmed by X-ray diffraction (XRD), Raman, and Fourier transform infrared (FTIR) spectroscopy techniques. In addition, the morphological features, chemical composition, and surface area of the NBNG nanograins were analyzed by field-emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and Brunauer–Emmett–Teller (BET) techniques. Electrochemical studies confirm that the NBNG displayed a specific capacitance of 684 F g–1 at 1 A g–1 with a retention of 73.6% after 5000 cycles, which is found to be a very promising value compared to the data reported so far. Further, its asymmetric coin cells prepared by using activated carbon (AC) as the opposite electrode (NBNG//AC) displayed a very encouraging specific capacitance of 138.86 F g–1 at 1 A g–1 (with a retention of 83% after 5000 cycles), an energy density of 59.06 Wh kg–1, and a power density of 1166.67 W kg–1. Inspired by these values, we further used an NBNG//AC supercapacitor device to power the Arduino microcontroller circuit-based temperature sensor device. The sensor device powered by four NBNG//AC coin cells showed the desired temperatures to be between 25 and 34 °C. The electrochemical results of NBNG//AC reported in this work will surely inspire many material scientists to further explore and develop highly functional transition metal borate-based materials for energy and electronic device applications.