Multifunctional bio carbon: a coir pith waste derived electrode for extensive energy storage device applications

Abstract

As a sequel to our earlier findings on the suitability of coir pith derived carbon (CPC) in lithium-ion and lithium sulfur batteries, the extended suitability of CPC electrode for sodium-ion batteries (SIBs) and electrical double layer capacitors (EDLCs) has been demonstrated through the present work. Herein, the activation temperature of CPC plays a vital role and an optimum temperature of 850 °C is found to be essential to demonstrate superior electrochemical performance in sodium-ion batteries and the product is denoted as CPC-850. An initial capacity of 280 mA h g⁻¹ and a progressive capacity of 220 mA h g⁻¹ up to 300 cycles with negligible capacity fading have been observed at 50 mA g⁻¹. Furthermore, CPC-850 delivers ∼110 mA h g⁻¹ for 1000 cycles at 1 A g⁻¹ and demonstrates tolerance up to 5 A g⁻¹, corresponding to 13.44C rate. In EDLCs, a CPC-850 symmetric cell exhibits 191 F g⁻¹ at 0.1 A g⁻¹ current density. Notably, CPC-850//CPC-850 withstands rated currents such as 1, 2, 5 and 10 A g⁻¹ and delivers 168, 152, 150 and 128 F g⁻¹ up to 10 000 cycles. Hence, the multifunctional capability and versatile suitability of the CPC electrode in electrochemical energy storage devices could be understood.