A decade of advanced rechargeable batteries development guided by in situ transmission electron microscopy

Abstract Advanced rechargeable batteries (ARBs) with the properties of green resource, safe operation and low cost, have received much attention due to the continually depletion of fossil fuels and the deterioration of global environment. The increasing pursuit of energy is pushing scientists to develop superior ARBs and it is a prerequisite to learn an in-depth understanding for components evolution and fundamental mechanism of electrode materials during charge and discharge process. As a state-of-art technique in the past few years, in situ transmission electron microscopy (TEM) presents high temporal and spatial resolutions in real-time observation, suggesting that the nonequilibrium state information can be probed during dynamic operating conditions. This powerful tool allows the direct observation of the electrode materials for the morphology change and electrochemical interface evolution during charge and discharge process. In addition, phase transformation can also be detected, and more detailed information about lattice information, crystallographic defect and element information will even be revealed. Currently, in situ TEM characterizations are initially employed for the investigation of ARBs electrode materials, which can visualize the complex electrochemical reaction at nano or even atomic scale. In this review, we conclude five kinds of classifications of in situ TEM setups for the monitoring ARBs and illuminate their detailed specific features. Besides, important imaging results from these published works within the past 10 years (2010–2020) are comprehensively analyzed. With the constant improvement of in situ TEM setups, some critical electrochemical reactions can be observed, which further facilitate the design of electrode materials for ARBs. In addition, we also propose how to utilize in situ TEM techniques to further settle the main challenges of ARBs and summarize the main challenges to further develop in situ TEM techniques in future. We believe this technique will play a vital role in investigating more underlying mechanism for ARBs.