Strain Engineering to Modify the Electrochemistry of Energy Storage Electrodes

Abstract

Strain engineering has been a critical aspect of device design in semiconductor manufacturing for the past decade, but remains relatively unexplored for other applications, such as energy storage. Using mechanical strain as an input parameter to modulate electrochemical potentials of metal oxides opens new opportunities intersecting fields of electrochemistry and mechanics. Here we demonstrate that less than 0.1% strain on a Ni-Ti-O based metal-oxide formed on superelastic shape memory NiTi alloys leads to anodic and cathodic peak potential shifts by up to ~30 mV in an electrochemical cell. Moreover, using the superelastic properties of NiTi to enable strain recovery also recovers the electrochemical potential of the metal oxide, providing mechanistic evidence of strain-modified electrochemistry. These results indicate that mechanical energy can be coupled with electrochemical systems to efficiently design and optimize a new class of strain-modulated energy storage materials.

Highly Active Core–Shell Carbon/NiCo2O4 Double Microtubes for Efficient Oxygen Evolution Reaction: Ultralow Overpotential and Superior Cycling Stability

“…Further enlarging the XRD results between 40 and 50° of 2θ (Figure b), the 2θ angle of NCO‐400‐N 2 was bigger, suggesting a smaller lattice distance than that of NCO‐400‐Air. Based on the XRD results, the strain in lattice could be calculated according to Here, ε represents the strain in crystal lattice, d 1 represents the crystal distance of NCO‐400‐Air, θ 1 represents the diffraction angle of NCO‐400‐Air, d 2 is the crystal distance of NCO‐400‐N 2 , and θ 2 is the diffraction angle of NCO‐400‐N 2 , respectively.…”

Discovery of a Multinary Noble Metal–Free Oxygen Reduction Catalyst

“…Hence, we hypothesize that catalytic activity cannot be solely predicted based on the properties of the constituent elements, and superior multinary catalysts do not uniquely rely on the position of their elements in such volcano plots alone. Strain effects or interparticle distance were shown to affect electrocatalytic activity. Strain effects can be strongly modulated in multinary solid solutions; however, more importantly, the homogeneous distribution of all elements induces a numerous amount of new active site configurations with different constitutions of neighboring atoms electronically interacting with each other.…”

Curvature-Induced Modification of Mechano-Electrochemical Coupling and Nucleation Kinetics in a Cathode Material

“…16,17,41 Yet only recently have the effects of lattice strain been systematically explored as a potential means of improving the functional performance of Li-ion batteries. 15,42 Pint and coworkers demonstrated that the application of a modest biaxial tensile strain in the ab plane of V 2 O 5 (1.66%) can modulate the intercalation potential and improve the diffusion kinetics of Li ions by as much as 40 mV and 250%, respectively. 15 However, the promise of strain-induced performance improvements described in these works is limited practically by the need for epitaxial films for which strain is dissipated with increasing film thickness.…”

“…The observed relationship between increasing lithiation rates at higher curvatures parallels the effects of applied strain. 15,42 Mapping of mesoscale domain formation through region of interest (ROI) analysis, PCA, and SVD provide meaningful insight into the spatial distribution of lithiated phases between and within individual particles. The STXM images collected for the three particle morphologies shown in Figures 1B-1D are evaluated using these techniques in greater detail below.…”