Name: Ms. Manisha Sanawa
Research Supervisor: Prof. Aninda Jiban Bhattacharyya
Title: Exploring Electrode Materials for Rechargeable Calcium-ion Batteries
Lithium-ion batteries have long dominated modern energy-storage systems. However, concerns over lithium’s supply chain and its uncertainty in providing sustainable energy storage, especially for large-scale applications, have accelerated the search for alternative chemistries.[1] Multivalent-ion batteries have gained attention as an alternative, owing to their natural abundance and multi-electron redox capability.[2] Among them, calcium-ion batteries stand out due to their crustal abundance and redox potential comparable to that of lithium.
Usage of aqueous electrolytes further enhances safety, cost-effectiveness, and environmental compatibility. However, the instability of calcium metal in aqueous media precludes its direct use as an anode.[3] Additionally, the relatively large hydrated radius of Ca²⁺ makes it imperative to seek host materials capable of accommodating and reversibly storing hydrated ions without significant structural degradation.[4] Motivated by this challenge, the present thesis focuses on exploring multiple classes of electrode materials as a host for aqueous calcium-ion batteries.
As part of this thesis, we explore various types of electrode systems, both organic and inorganic materials (e.g., Prussian blue analogues, layered oxides).[5] A key challenge across these materials is the capacity fade that arises from lattice distortion, structural phase transitions, and morphological changes during cycling. This thesis focuses on identifying the dominant degradation pathways and proposes strategies to enhance structural stability and electrochemical reversibility.[6] In addition, complementary studies on non-aqueous electrolytes were conducted to assess the dynamic nature of the solid electrolyte interphase (SEI) on calcium metal over time and its electrochemical performance.[7]