Abstract: Described herein are devices and methods for flash freezing samples while applying an in situ electrical current or bias. Advantageously, the present application is directed towards materials, such as batteries or electrochemical cells, where applying an electrical current or bias leads to dynamic changes to the structure and chemistry of constituent materials, which underpin device performance and degradation. By concurrently applying electrical current or bias and flash freezing the sample, transient structures in the anode, cathode, or electrolyte can be observed with a high degree of temporal resolution at an atomic scale.

Abstract: A portable, compact gas delivery system can support an environmental transmission electron microscope. Environment transmission electron microscopy provides researchers a unique capability of assessing a material's surface conditions at atomic resolution in a variety of reactive and oxidizing environments. The ability to precisely control the analysis chamber's environmental conditions over time is key to the success of a typical surface analysis. The gas delivery system provides the correct balance or pressure delivery precision, contamination control, and gas isolation.

Abstract: The contact pressure on the surface of the electrodes in lithium metal anodes can be used to control the electrodeposited lithium morphology and suppress lithium short circuiting in lithium ion batteries. For example, the contact pressure on the electrode surfaces can be controlled using a load frame in a pouch cell configuration, which allows constant force to be applied over a variety of contact pressures from 0-1 MPa. In a coin cell configuration, compression can be controlled using a wave spring, Belleville washer, or one or more pieces of metal foam. Higher pressures produce larger lithium grains and suppress dendrite formation. Although high contact pressure suppresses observable lithium dendrites, short circuiting can occur at the high contact pressures. Therefore, there is an optimal contact pressure for controlled electrodeposited lithium morphology.