Kartik Sau 교수

Abstract All-solid-state batteries (ASSBs) are promising alternatives to conventional lithium-ion batteries. ASSBs consist of solid-fast-ion-conducting electrolytes and electrodes that offer improved energy density, battery safety, specific power, and fast-charging capability. Despite decades of intensive research, only a few have high ionic conductivity at ambient temperature. Developing fast ion-conducting materials requires both synthesis of high-conducting materials and a fundamental underst

An interatomic potential is proposed for the recently discovered family of superionic solids of the formula Na2M2TeO6, where M = Ni, Zn, Co, or Mg. Molecular dynamics simulations demonstrating the quality of the potential in reproducing various structural and transport properties of this promising class of materials is presented. The study provides fresh insights on the microscopic energetics and Na+ migration pathways. Strong ion–ion correlations, resulting in a highly cooperative conduction me

A series of molecular dynamics (MD) simulations are carried out, in which the Na+ content at the interlayers of Na2Ni2TeO6 is systematically varied, keeping the overall charge neutrality of the system, to identify the role of ion–ion correlation on Na+ diffusion in the system. It has been observed that interlayers having about 20% lower concentration of Na+ facilitate the highest conductivity that is one order of magnitude higher than those having normal Na+ concentration. The simulations predic

Complex hydrides are potential candidates for the solid electrolyte of all-solid-state batteries owing to their high ionic conductivities in which icosahedral anion reorientational motion plays an essential role in high cation diffusion. Herein, we report molecular dynamics (MD) simulations based on a refined force field and first-principles calculations of the two complex hydride systems Li2B12H12 and LiCB11H12 to investigate their structures, order–disorder phase-transition behavior, anion reo

Na3PS4 has received significant attention as a solid electrolyte for use in all-solid-state batteries because of its high ionic conductivities. In this work, we performed a series of molecular dynamics simulations using a refined set of potential parameters to study the origin of the high conductivity in the recently reported γ-phase. The potential model successfully reproduced the structural and dynamical behavior of the system. Importantly, it could reproduce the high- to low-temperature phase

Traditional refrigeration technologies based on compression cycles of greenhouse gases pose serious threats to the environment and cannot be downscaled to electronic device dimensions. Solid-state cooling exploits the thermal response of caloric materials to changes in the applied external fields (i.e., magnetic, electric and/or mechanical stress) and represents a promising alternative to current refrigeration methods. However, most of the caloric materials known to date present relatively small

Abstract Solid‐state methods for cooling and heating promise a sustainable alternative to current compression cycles of greenhouse gases and inefficient fuel‐burning heaters. Barocaloric effects (BCE) driven by hydrostatic pressure ( p ) are especially encouraging in terms of large adiabatic temperature changes (|Δ T | ≈ 10 K) and isothermal entropy changes (|Δ S | ≈ 100 J K −1 kg −1 ). However, BCE typically require large pressure shifts due to irreversibility issues, and sizeable |Δ T | and |Δ

${\mathrm{Li}}_{2}{\mathrm{B}}_{12}{\mathrm{H}}_{12}$ and its derivatives are promising solid electrolytes for solid-state batteries. In this work, a potential model is proposed, and an extensive classical molecular dynamics study is performed to understand the origin of the fast ion conduction in ${\mathrm{Li}}_{2}{\mathrm{B}}_{12}{\mathrm{H}}_{12}$. The proposed potential model reveals structural and dynamical properties of ${\mathrm{Li}}_{2}{\mathrm{B}}_{12}{\mathrm{H}}_{12}$ that are consist

The derivatives of LiTi2(PO4)3 are promising electrolytes for solid-state batteries. An extensive molecular dynamics study is performed employing a refined set of potential parameters to understand the influence of Ba substitution on Li+ ion conductivity in Bax/2Li1-xTi2(PO4)3 (0.0 ≤ x ≤ 0.83). The refined set of potential parameters reveals the structural and dynamical properties of Bax/2Li1-xTi2(PO4)3 which are consistent with experimental results. In the presence of Ba2+, the system endures a

Honeycomb-layered oxides have attracted recent attention because of their rich crystal chemistry. However, the atomistic mechanisms of cationic transport in these structures remain vastly unexplored. Herein, we perform an extensive, systematic molecular dynamics study on ${\mathrm{Na}}_{2}{\mathrm{LiFeTeO}}_{6}$ using combined force-field and first-principles-based molecular dynamics simulations. We use a refined set of interatomic potential parameters of a previously reported potential model th

The ordered–disordered transition temperature is reduced significantly with increasing cationic sizes. A possible principle for creating better ion-conducting materials is to have smaller cations in a larger unit cell.

We present an extensive molecular dynamics study performed systematically using a reliable set of inter-atomic potential parameters of A2Ni2TeO6 (where A = Li, Na, and K). We demonstrate the effectiveness of the inter-atomic potential that represents various structural and transport properties of this promising class of materials and predict an exponential increase in cationic diffusion with larger inter-layer distances. The simulations demonstrate the correlation between broadened inter-layer d

Although the fascinatingly rich crystal chemistry of honeycomb layered oxides has been accredited as the propelling force behind their remarkable electrochemistry, the atomistic mechanisms surrounding their operations remain unexplored. Thus, herein, we present an extensive molecular dynamics study performed systematically using a reliable set of inter-atomic potential parameters of A2Ni2TeO6 (where A = Li, Na, and K). We demonstrate the effectiveness of the Vashishta-Rahman form of the inter-at

Molecular dynamics (MD) study of Na+ transport in Na2Ni2TeO6 is performed systematically with varying strengths of Na+-Na+ repulsions. This virtual experiment is performed to understand the physics of the ion transport. The optimal short range Na-Na repulsion exhibits highest Na+ diffusion. The Na+ occupancy shows a systematic shift in favor of higher energy and the connecting channels between the interstitial sites are thicker as the short range repulsion between Na+ is increased. The microscop