Graphene incorporated mesoporous perovskite with excellent conductivity and catalytic activity for low temperature solid oxide fuel cells

Abstract

In modern times, energy transformation sources with superior efficacy and eco-friendliness have become remarkably attractive in terms of fuel cell technology. In this regard, graphene-incorporated nanocomposites show strong catalytic activity as anode materials in fuel cells, especially in solid oxide fuel cells (SOFCs). In this work, a sol–gel protocol was followed for the synthesis of perovskite and graphene-incorporated perovskite anode materials with compositions La_0.6Sr_0.4Al_0.2Cu_0.8O₃ and La_0.6Sr_0.4Al_0.2Cu_0.8O₃–graphene, respectively. The material properties of the prepared composites were studied using various techniques, such as SEM, FTIR, XRD, EDX, BET, and DSC. The DSC and BET studies confirmed that the graphene-incorporated perovskite is more stable thermally with a mesoporous structure and a narrow pore size distribution. The conductivities of the materials were studied using a 4-probe DC conductivity technique. The maximum electrical conductivities attained were 78.7 S cm⁻¹ at 500 °C for La_0.6Sr_0.4Al_0.2Cu_0.8O₃–graphene and 10.6 S cm⁻¹ at 700 °C for La_0.6Sr_0.4Al_0.2Cu_0.8O₃. The fuel cell performances were checked via the fabrication of asymmetrical cells comprising three layers, i.e., anode, electrolyte, and cathode materials. The maximum open circuit voltage (OCV) and power density were obtained as 1.024 V and 513 mW cm⁻² at 550 °C with La_0.6Sr_0.4Al_0.2Cu_0.8O₃–graphene, using air as the oxidant and hydrogen as the fuel. Therefore, this catalytic material could play a vital role in advancing the performances of SOFCs working at low temperatures.