Research Projects

1.Origin of proposal The push for zero emissions and SDG 7 has driven clean energy research, especially solar-powered storage. Solar-grid system, EVs, and drones have increased battery demand. Batteries for drones and house purpose are lightweight, high-energy batteries like 21700 cells, valued for their 5000 mAh capacity and energy density. However, the compact 21700 cells with high energy density liberate tremendous heat during its charging/discharging for longer cycles. Ohmic Joule heating, reaction heat, entropic heat, and side reactions are vital in heat generation. Temperature of the cell need to be controlled otherwise it disrupts its performance. To ensure its best performance, the temperature shall be maintained below 50 ⁰C. Among all strategies, passive cooling using phase change materials (PCM) with cascading is a novel strategy, which is having multiple PCM in staggered nature with high-to-low phase transition temperature. Also, despite their several advantages, conventional PCMs like paraffin and fatty acids suffer from low thermal conductivity (~0.2 W/m·K) and leakage issues during solid-to-liquid phase transitions. To overcome these limitations, the fabrication of composite PCMs (CPCMs) embedded with nanoplatelet-like structured materials and porous scaffolds has garnered significant interest. This proposal aims to develop prototype based on boron nitride and porous scaffold incorporated in PCM cascading. 2.Hypothesis and Methodology PPCMs absorb and release thermal energy during phase transitions, enabling efficient thermal management. For high-heat-generating 21700 cells, PCM absorbs heat upon melting and releases it during solidification. A cascade PCM, using multiple PCMs with different melting points in sequence, allows gradual heat absorption. This work includes: (i) preparation of boron nitride nanoplatelets (BN) and porous scaffold, (ii) fabrication of BN and scaffold-incorporated cascade PCM, and (iv) thermal evaluation. BN nanoplatelets enhance thermal conductivity, while porous scaffolds ensure shape stability. The cascade system positions higher melting point PCM near the 21700 cell, followed by lower melting point PCM. As temperature rises, each PCM melts in turn, absorbing heat progressively. Compared to single PCM systems, cascade PCMs offer better thermal regulation, extended cooling time, improved safety, and enhanced battery lifespan, making them ideal for applications like drones where thermal spikes are frequent. 3. Objectives • Design and synthesize a porous scaffold structure infused with Boron nitride nanoplatelets to host phase change materials (PCM) •Development PCM with enhanced thermal conductivity (5x) and shape stabilization •Development of functionally-graded phase change materials with cascading concept •Evaluate the thermal regulation performance of the cascade PCM composite for 21700 cells •Develop a prototype with temperature control for solar battery with real-time monitoring.