Local Lithiation via Nanobattery Probes: Battery Interfaces at the Nanoscale

Greater knowledge of interfacial charge/mass transport processes in battery materials - especially as a function of lithiation - is essential to understand and overcome materials limitations in performance. Increased use of nanostructured and/or nanoscale electrodes in energy storage systems, calls for research tools that allow for direct, local probes of materials interfaces and inhomogeneity. Here we present a new approach to measure local interfacial structure, electronics, and electrochemical properties as a function of local chemical changes, like lithiation. Building upon our laboratory's recent success in developing scanning probe techniques for energy storage science [1], we introduce novel probes layered with nanothin, functional energy-storage materials. We perform in situ measurements of the electronic properties of oxide-clad probes, via electron tunneling spectroscopy, determining effective electron transport gaps. We then utilize these probes as fine Li sources and as nanobattery probes for local cycling against a silicon anode substrate. Post lithiation, conventional in-situ STM and SEM reveal local physical changes in the cycled Si(111) anode surface. [1] J.M. Larson et al, Small, 2015, DOI: 10.1002/smll.201500999