In situ characterization of charge rate dependent stress and structure changes in V2O5 cathode prepared by atomic layer deposition

Abstract

The insertion/extraction of lithium into/from various host materials is the basic process by which lithium-ion batteries reversible store charge. This process is generally accompanied by strain in the host material, inducing stress which can lead to capacity loss. Therefore, understanding of both the structural changes and the associated stressinvestigated almost exclusively separate to dateis a critical factor for developing highperformance batteries. Here, we report an in situ method, which utilizes Raman spectroscopy in parallel with optical interferometry to study effects of varying charging rates (C-rates) on the structure and stress in a V 2 O 5 thin film cathode. Abrupt stress changes at specific crystal phase transitions in the Li-V-O system are observed and the magnitude of the stress changes with the amount of lithium inserted into the electrode are correlated. A linear increase in the stress as a function of x in Li x V 2 O 5 is observed, indicating that Crate does not directly contribute to larger intercalation stress. However, a more rapid increase in disorder within the Li x V 2 O 5 layers is correlates with higher Crate. Ultimately, these experiments demonstrate how the simultaneous stress/Raman in situ approach can be utilized as a characterization platform for investigating various critical factors affecting lithium-ion battery performance.

Interfacial Incompatibility and Internal Stresses in All‐Solid‐State Lithium Ion Batteries

“…Inspired by this, H. Jung et al [334] described that lithium intercalation produced an increasing tensile stress in the Li x V 2 O 5 , as shown in Figure 18d. The Raman spectroscopy capturing the structural and chemical information of the electrodes is understandable upon Li insertion/removal.…”

“…[331] Considering the fact that the inherent reason generated the strains/stresses should lie on the electrochemically driven structural change, the strains/stresses within the electrodes were, therefore, highly rate-dependent. [334] Copyright 2017, Elsevier. Energy Mater.…”

“…[333,334] The MEMS optical sensor contained an array of flexible circular membranes coated on the electrode surface (Figure 18c). The stresses will be calculated by monitoring the membrane deflection using optical interferometry [334] …”

“…Reproduced with permission. [334] Copyright 2017, Elsevier. e) Schematic drawing of a typical synchrotron operando XRD technique to monitor the strain/stress level in the anode/cathode, and evolution of d-spacing of the (111) plane upon discharging of the Ge particle.…”

“…an in situ experimental setup (Figure 18b) combining a microelectromechanical systems (MEMS) optical sensor with Raman spectroscopy to concurrently monitor the real-time stress and structural change in the electrodes. [333,334] The MEMS optical sensor contained an array of flexible circular membranes coated on the electrode surface ( Figure 18c). The stresses will be calculated by monitoring the membrane deflection using optical interferometry [334]…”