Research Activities in Khani Laboratory of Electrochemistry and Materials Science
Khani’s work spans a diverse array of interdisciplinary projects in materials science and engineering, including the thermal and electrochemical failure mechanisms of next-generation batteries, electrochemical energy storage, sensors, electrocatalysis, electroplating, scanning electrochemical microscopy, and chemometrics. The current focus of research in the Khani Laboratory includes the design and synthesis of polymer and inorganic fast ion-conducting solid-state and quasi-solid-state electrolytes, polymer-based cathodes, and the characterization of thermal stability, gas evolution, interphase degradation, structural evolution, and cell-level failure behavior in emerging battery chemistries, including solid-state, lithium-metal, sodium-ion, and potassium-ion batteries.
Thermal and Electrochemical Failure Mechanisms of Next-Generation Batteries
Thermal stability, gas evolution, interphase degradation, and failure behavior are among the most important safety challenges facing next-generation battery technologies, including solid-state, lithium-metal, sodium-ion, potassium-ion, and other high-energy-density cells. Our lab is building a focused research program to understand how these systems respond under normal operation, elevated temperature, overcharge, overdischarge, and other abusive electrochemical and thermal conditions. Our work connects materials-level reactions with cell-level failure behavior by tracking heat generation, gas evolution, structural changes, interphase degradation, and internal cell failure in real time. This approach allows us to identify the origins of failure, determine reaction pathways, and understand how electrode, electrolyte, interphase, and cell-design choices influence battery reliability and thermal stability. Our capabilities include an integrated suite of operando, in situ, and ex situ characterization tools for probing thermally driven and electrochemically driven degradation pathways:
The goal of this research area is to establish a mechanistic understanding of battery failure across materials, interfaces, and full cells. Our vision is to develop new testing methods, failure mode and effects analysis (FMEA), improved safety metrics, and science-based guidelines that help de-risk the commercial adoption of emerging battery technologies through collaborations with academic, national laboratory, and industry partners.
Solid-State Lithium-Metal Batteries
Our main research focus is dedicated to advancing solid-state batteries with a Li+-conducting solid-state electrolyte and lithium-metal anode, which promise higher energy density and enhanced safety compared to traditional lithium-ion batteries with carbon anode and flammable liquid electrolyte. We focus on developing and optimizing different types of solid-state electrolytes to overcome current limitations in solid-state batteries.
Inorganic Solid-State Electrolyte: Our interest in inorganic solid electrolytes centers around oxide-based solid-state electrolytes, such as garnet-type and NASICON-type oxides, due to their superior anodic and cathodic stability, high ionic conductivity, mechanical strength, and thermal stability. Our research involves developing new materials and synthesis methods to increase Li+ ion conductivity, reduce synthesis costs, and improve the interface chemistry between the solid electrolyte and both the cathode and lithium-metal anode, with the ultimate goal of improving battery performance and longevity.
Polymer Electrolyte: We design and synthesize fast Li+-conducting polymer electrolytes, including polyethylene oxide-perfluorinated electrolytes, single-ion-conducting polymer electrolytes, and quasi-polymer electrolytes. Our polymer design strategy focuses on achieving a polymer electrolyte with high room-temperature Li+ conductivity (e.g., 10-3 S/cm), high interface stability with NMC cathodes, and high mechanical strength. A key advantage of polymer electrolytes is their high flexibility, making them compatible with current lithium-ion battery production processes.
Composite-Polymer Electrolyte: We work on composite-polymer electrolytes to combine the benefits of inorganic fillers (e.g. high Li+ conductivity of 10-3-10-4 S/cm and high Young’s modulus of 100-150 GPa) and polymer matrices (high film flexibility, processability, and high electrolyte/electrode interface contact). By incorporating nanoparticles or nanofibers of inorganic fillers into polymer electrolytes, we aim to boost ionic conductivity, mechanical robustness, and interfacial stability. This hybrid approach seeks to overcome the shortcomings of individual electrolyte systems in all solid-state batteries.
Metal Oxide Anode for Ultrafast-Charging Applications
We work on different metal oxide anodes, including TiNb2O7, Nb2O5, and V2O5, for fast-charging and low-temperature applications, where traditional lithium-ion batteries with carbon anodes have significant limitations. The goal is to increase the intrinsic ionic and electronic properties of these metal oxides and improve the interface of liquid electrolyte with these metal-oxide anodes to enable safe, fast-charging applications (e.g., 10C, 6 minutes). We use various electrochemical and computational tools to understand the ionic and electronic conduction mechanisms in these materials, allowing us to tune their chemistry for target applications.
Electrocatalysis
In this area, we aim to investigate the structure-activity relationships in electrocatalyst materials using advanced operando electrochemical and surface characterization techniques such as operando surface-enhanced Raman spectroscopy and scanning electrochemical microscopy. Our goal is to delve into the mechanisms of electrochemical reactions—such as carbon dioxide reduction (CO2RR), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), and hydrogen evolution reaction (HER)—on metal-based electrocatalysts, ultimately using this information to enhance activities and selectivities.
Sponsors
