Profile — Dr. Ayush Chandra Pundir

An undergraduate training in mechanical engineering at Dehradun Institute of Technology provided a grounding in thermodynamics, transport and mechanical behaviour that later proved useful in understanding electrode degradation and cell-level constraints.

The move into materials science came with the M.Tech at NIT Hamirpur, where work on single-phase zinc stannate introduced sol-gel synthesis, phase analysis and the discipline of relating processing conditions to measured structure. That programme concluded with a Gold Medal.

Doctoral study at IIT Roorkee, under Prof. Anjan Sil, then concentrated the work on lithium-sulfur systems and, over seven years, extended it from single-material synthesis to complete cell design.

The unifying question across this work is how the arrangement of matter at a few nanometres governs what a cell does over hundreds of cycles. Sulfur cathodes make that question unusually sharp, because their failure modes are chemical, structural and kinetic at once.

Rather than optimising a single component, the approach treats the host, the separator and the interface between them as one coupled system. A polar oxide that anchors polysulfides is only useful if the surrounding carbon still conducts and the pore network still admits ions.

Materials are synthesised in-house by hydrothermal and sol-gel routes, then characterised structurally and chemically before any electrochemical claim is made — XRD with Rietveld refinement, Raman, BET, FE-SEM, HR-TEM and XPS as the work requires.

Electrodes are fabricated and coin cells assembled in a controlled glove-box environment. Evaluation combines cyclic voltammetry, galvanostatic charge-discharge, impedance spectroscopy, GITT and extended cycling.

Post-mortem examination of disassembled cells is treated as part of the experiment rather than an afterthought: recovered separators and electrodes frequently explain a capacity trend that the cycling curve alone cannot.

Lithium-ion technology is mature, but the materials it depends on are constrained in cost and availability. Sulfur and sodium are abundant, and the chemistry is attractive — the obstacles are interfacial and kinetic rather than thermodynamic.

That makes the field a materials problem in the strictest sense, and one where careful synthesis and honest characterisation still change outcomes.

The near-term intention is to carry adsorption-and-catalysis separator designs into more demanding conditions: higher sulfur loading, leaner electrolyte, and full cells rather than half cells, where reported gains are frequently harder to sustain.

Over a longer horizon the interest extends to solid-state and quasi-solid-state components, and to the recovery and reuse of active materials from spent cells — closing the loop between what a battery is made from and what becomes of it.

Students learn electrochemistry most durably when they are asked to interpret real data, including data that does not behave. Laboratory sessions and literature discussion are therefore treated as instruction, not supplement.

In mentoring, the aim is to move a student from following a protocol to designing one: choosing a measurement because it discriminates between two explanations, and reporting the result whichever way it falls.