Nanoscale visualization of redox activity at lithium-ion battery cathodes

Abstract

Intercalation and deintercalation of lithium ions at electrode surfaces are central to the operation of lithium-ion batteries. Yet, on the most important composite cathode surfaces, this is a rather complex process involving spatially heterogeneous reactions that have proved difficult to resolve with existing techniques. Here we report a scanning electrochemical cell microscope based approach to define a mobile electrochemical cell that is used to quantitatively visualize electrochemical phenomena at the battery cathode material LiFePO 4 , with resolution of B100 nm. The technique measures electrode topography and different electrochemical properties simultaneously, and the information can be combined with complementary microscopic techniques to reveal new perspectives on structure and activity. These electrodes exhibit highly spatially heterogeneous electrochemistry at the nanoscale, both within secondary particles and at individual primary nanoparticles, which is highly dependent on the local structure and composition.

Nanoscale Electrochemistry of sp2 Carbon Materials: From Graphite and Graphene to Carbon Nanotubes

“…A similar, fast ET response was found for Fe(CN)6 4-/3-, but measurements had to be made rapidly following HOPG cleavage, to avoid a deterioration of the response. 15 Although SMCM can now be used with pipets as small as 100 nm diameter, 16 scanning electrochemical cell microscopy (SECCM)…”

Development of High-Resolution Scanning Electrochemical Microscopy for Nanoscale Topography and Electrochemical Simultaneous Imaging

“…32,33 We applied SECCM to the cathode material of lithium ion secondary batteries. 34 SECCM is effective for material research but is difficult for live cell imaging because the measurements must be performed under ambient conditions.…”

Characterization of local electrocatalytical activity of nanosheet-structured ZnCo 2 O 4 /carbon nanotubes composite for oxygen reduction reaction with scanning electrochemical microscopy

“…The increasing interest on developing novel MTMOs hybrids as ORR catalyst candidates thus raises a new request on high throughput electrochemical screening methods with high spatial resolution and also providing local electrocatalytic activity information of the MTMOs catalysts. Scanning electrochemical microscopy (SECM), as a kind of scanning probe microscope with using a microelectrode as probe, can provide the local reactivity of sample with high spatial and temporal resolutions based on the recorded probe currents [28][29][30][31][32][33][34]. And since only small amount of sample needed in SECM experiment and its rapid experimental process, SECM has the capability of quickly and simultaneously evaluating reactivities of different catalysts within one single experiment.…”