The ever-growing energy requirements, the decreasing fossil fuel resources and the urgent need for environmental protection have spurred the search for sustainable energy alternatives, including both renewable energy sources and efficient storage technologies. Lithium/sodium (Li/Na)-ion batteries (LIBs/SIBs) are the most attractive and promising energy storage devices in the consumer market. The primary progress made by using advanced transmission electron microscopy (TEM) characterization and its close correlation with the battery properties are reviewed here. In addition, the atomic structure and chemistry of electrode materials are illustrated with respect to the surface reconstruction and the interface structure. The phase transformation and defect evolution are then discussed with respect to (1) the intermediate state of LiFePO₄ that results in a high rate capability; (2) the in situ electrochemical reaction on nanomaterials; and (3) the alloying reaction for the high-energy-density silicon (Si) anode. The fundamental science underlying the microstructure evolution has been explored in depth to the atomic level and is discussed further in the context of electronic structure theory.

不断增长的能源需求，不断减少的化石燃料资源以及对环境保护的迫切需求促使人们寻求可持续能源替代品，包括可再生能源和高效存储技术。锂/钠（Li / Na）离子电池（LIB / SIB）是消费市场上最有吸引力，最有前途的储能设备。本文回顾了使用先进的透射电子显微镜（TEM）表征取得的主要进展及其与电池性能的密切关系。此外，还针对表面重建和界面结构说明了电极材料的原子结构和化学性质。然后针对（1）LiFePO的中间状态讨论了相变和缺陷演变₄导致高速率能力；（2）在纳米材料上的原位电化学反应；（3）高能密度硅（Si）阳极的合金化反应。微观结构演化的基础科学已深入到原子水平，并在电子结构理论的背景下进行了进一步讨论。