Research Projects

The scarcity of fossil fuels, rising pollution, and increasing demand for energy drive the necessity of extensive utilization of clean energy storage systems like supercapacitors (SCs) for practical applications. In India, two major issues that prevent the successful commercialization of SCs are i) the unavailability of suitable electrode materials and ii) the lack of expertise in handling volatile and moisture-sensitive electrolytes during cell designing. Thus, the current proposal is addressing the development of highly capacitive layered transition metal carbides (known as MXenes) based SCs with aqueous electrolytes to enable the manufacturing of efficient SCs, in ambient conditions. Among the various types of MXenes, the M₂X type shows ~50% higher gravimetric capacitance than other types because exposure of their M surface to electrolyte remains maximum which means better electrode/electrolyte interaction than others. Therefore, here, we will be developing M₂X type MXenes having M=Ti/V, & X=C. The use of Ti/V containing MXenes for SCs is possibly advantageous due to their unique structure and properties such as containing multiple redox active sites, large interlayer spacing for accepting the electrolytic ions, excellent electrical conductivity to help smooth charge transfer, and high surface area. However, parent MXenes suffer from the poor surface area (due to their high agglomeration tendency in solution) which causes insufficient active sites, interrupted charge transfer, and finally low storage performance. Therefore, structural and compositional modifications of Ti₂C and V₂C MXenes are here proposed to prepare 0D dots and hollow spheres, 1-3 layered 2D-sheets, 3D porous networks, and composites with transition metal oxides to enrich their surface and electrochemical properties. However, another major problem is (for almost all the MXenes based SCs) the unavailability of precursor MAX phases (requires to derive MXenes) of high purity, and in large quantity. To the best of our knowledge, in India, no one is commercially manufacturing the required MAX phases, and globally also there are 2-3 companies who sells MAX of low purity (70-90%) at a very high price (1200-2000 INR/g). Few reports on the synthesis of Ti₂AlC and V₂AlC are also available but in lab scale and mostly need high-end sintering arrangements. Therefore, this proposal will first focus on developing M₂AlX type (M=Ti/V & X=C) MAX phases with 95% purity in 100-200 g scale by using a simple and cost-effective pressureless sintering process. After developing the desired MAXs, Ti₂C and V₂C MXenes will be derived and modified structurally and compositionally to manufacture SC devices having 80-100 F of capacitance and energy density of 20-30 Wh/kg in two different forms i.e. 2032 type coin and 18650 type cylindrical cell with the practical demonstration of the devices by running the consumer electronics like pulse oximeter, hand-blender, trimmer, and toys.

MAX, MXenes, pressureless sintering, electrodes, aqueous-electrolytes, supercapacitors