In-situ/operando characterization techniques in lithium-ion batteries and beyond

Nowadays, in-situ/operando characterization becomes one of the most powerful as well as available means to monitor intricate reactions and investigate energy-storage mechanisms within advanced batteries. The new applications and novel devices constructed in recent years are necessary to be reviewed for inspiring subsequent studies. Hence, we summarize the progress of in-situ/operando techniques employed in rechargeable batteries. The members of this large family are divided into three sections for introduction, including bulk material, electrolyte/electrode interface and gas evolution. In each part,various energy-storage systems are mentioned and the related experimental details as well as data analysis are discussed. The simultaneous strategies of various in-situ methods are highlighted as well. Finally,current challenges and potential solutions are concluded towards the rising influence and enlarged appliance of in-situ/operando techniques in the battery research.