Pitfalls in Electrochemical Liquid Cell Transmission Electron Microscopy for Dendrite Observation

The growth of dendrites on the electrodes during charge-discharge cycles can lead to short-circuit and potential ignition, which limit the capacity and application of the rechargeable batteries. With the development of in situ electrochemical liquid cell transmission electron microscopy, the growth process of metallic dendrites can be observed in real-time. However, there remains a great challenge to operate the electrochemical liquid cell experiments successfully and repetitively. Herein, the lithium-ion battery electrolyte system and the other electrolyte system of silver nitrate with sodium nitrate aqueous solution are adopted in our experiments to demonstrate the problems in conducting electrochemical liquid cell experiments. Influence factors are summarized, including the tube residual, cleanliness of electrodes, bubbles in the liquid cell, and the stability of the electrochemical system. All these aspects affect the electrochemical liquid cell experiments, and understanding these influencing factors is beneficial to improve the success rate of experiments. This work may offer guidance for the wide application of in situ electrochemical liquid cell transmission electron microscopy in observing the growth of dendrites in batteries.