Operando pair distribution function analysis of nanocrystalline functional materials: the case of $\mathrm{Ti}{\mathrm{O}}_2$-bronze nanocrystals in Li-ion battery electrodes

Abstract

Structural modelling of $operando$ pair distribution function (PDF) data of functional materials can be highly complex. To aid the understanding of complex operando PDF data, we here demonstrate a toolbox for PDF analysis. The tools include the structureMining, similarityMapping, nmfMapping apps available through the online service 'PDF in the cloud' (PDFitc, www.pdfitc.org), as well as noise-filtering using principal component analysis (PCA). The tools are applied to both ex situ and operando PDF data for 3 nm $\mathrm{Ti}{\mathrm{O}}_2$-bronze nanocrystals, which function as the active electrode material in a Li-ion battery. The tools enable structural modelling of the ex situ and operando PDF data, revealing two pristine $\mathrm{Ti}{\mathrm{O}}_2$ phases (bronze and anatase) and two lithiated $\mathrm{L}{\mathrm{i}}_{\mathrm{x}}\mathrm{Ti}{\mathrm{O}}_2$ phases (lithiated versions of bronze and anatase), and the phase evolution during Galvanostatic cycling is characterized.

Preprint, 82 pages in total (front page: 1 page, abstract: 1 page, paper: 34 pages, supporting information: 40 pages, references: 5 pages, synopsis: 1 page), 35 figures in total (frontpage: 1 figure, paper: 8 figures, supporting information: 26 figures)