Materials Design Rules for Multivalent Ion Mobility in Intercalation Structures

Abstract

The diffusion of ions in solid materials plays an important role in many aspects of materials science such as the geological evolution of minerals, materials synthesis, and in device performance across several technologies. For example, the realization of multivalent (MV) batteries, which offer a realistic route to superseding the electrochemical performance of Li-ion batteries, hinges on the discovery of host materials that possess adequate mobility of the MV intercalant to support reasonable charge and discharge times. This has proven especially challenging, motivating the current investigation of ion mobility (Li + , Mg 2+ , Zn 2+ , Ca 2+ , and Al 3+ ) in spinel Mn 2 O 4 , olivine FePO 4 , layered NiO 2 , and orthorhombic δ-V 2 O 5 . In this study, we not only quantitatively assess these structures as candidate cathode materials, but also isolate the chemical and structural descriptors that govern MV diffusion. Our finding that matching the intercalant site preference to the diffusion path topology of the host structure controls mobility more than any other factor leads to practical and implementable guidelines to find fast-diffusing MV ion conductors.

Assessing Local Structure Motifs Using Order Parameters for Motif Recognition, Interstitial Identification, and Diffusion Path Characterization

“…We now apply the validated order parameters based structure motif recognition criteria and the order parameters themselves (as a degree of perfect-motif resemblance) to automatically find structure motifs in a large materials database , determine interstitials (Broberg et al, 2016), and analyze the coordination environment along solid-state jump-diffusion paths (Rong et al, 2015).…”

“…Finding and quantitatively assessing primary building blocks of zeolite materials (SiO 4 tetrahedra) can be used to predict the feasibility of synthesizing a (hypothetical) material (Li et al, 2013;Mazur et al, 2015) and to rate their likelihood for industrial deployment-for example, as a catalyst- . Design rules for novel battery materials are frequently developed employing information about the coordination pattern of the migrating ion (Rong et al, 2015) and the host structure (Li et al, 2009;Wang et al, 2015). Models based on structural fragments can be used to assess influencing factors to the superconductivity critical temperature (Isayev et al, 2015).…”

Fulfilling the promise of the materials genome initiative with high-throughput experimental methodologies

“…3), as well as in the Cr, Ti, and Mn sulfide spinels. Furthermore, Rong et al 71 formulated multivalent ionic mobility design rules as a function of structure type and coordination environment. Indeed, sluggish yet reversible Mg intercalation in Mn oxide spinels was subsequently proven 72 and, excitingly, recent work 73 experimentally demonstrated well-behaved Mg intercalation in the cubic TiS 2 spinel.…”

Titanium Sulfides as Intercalation-Type Cathode Materials for Rechargeable Aluminum Batteries

“…17 Our selection of transition metal sulfides in place of oxides as Al-ion cathode materials is crucial: Due to the strong Coulombic effect, the energy barrier for multivalent ion transport in the oxide crystal structure is high. 18 Therefore, a more polarizable (softer) anionic framework is needed for facile Al 3+ ion intercalation−extraction, making transition metal sulfides promising candidates as Al-ion cathode materials. Although Mo 6 S 8 showed unambiguous electrochemical Al intercalation−extraction properties, its specific capacity was not ideal due to its high molecular mass.…”