# Cobalt–Silicon Material Libraries Derived from High Throughput Experimentation and Their Application in Lithium Batteries

## TL;DR

This paper explores how combining silicon with cobalt in specific ratios can improve lithium battery performance by understanding phase formation and lithium ion movement.

## Contribution

The study uses high-throughput experimentation to reveal detailed phase formation in cobalt-silicon mixtures and their electrochemical behavior.

## Key findings

- Cobalt-silicon silicides form only in narrow compositional ranges.
- Lithium storage capacity decreases due to impeded lithium ion motion in these mixtures.
- High-throughput methods provide insights into phase formation and battery performance.

## Abstract

Silicon is one of
the most promising anode materials in lithium
batteries due to its high storage capacity; however, it suffers from
extensive volume changes during charge and discharge in a battery
cell. Mixtures of silicon with transition metals potentially forming
transition metal silicides are under intense investigation as mechanically
stable and electronically conductive frameworks with additional silicon
in between. The overall capacity for lithium storage in such mixtures
in general decreases with increasing transition metal content, and
the interpretation of the data in the literature is controversial.
In this work, it is shown how approaches toward high-throughput experimentation
allow a deeper insight into the details of phase formation in transition
metal silicides and thus their impact on the electrochemical performance
of silicon-silicide frameworks as electrodes for advanced lithium
batteries. Silicides appear to evolve solely in narrow compositional
ranges around commensurate ratios of cobalt and silicon, while the
observed capacity reduction is attributed to an impeded and finally
blocked motion of lithium ions.