Latest advances on operando analysis in the field of next-generation battery research are highlighted by means of three examples: recording the pressure change and performing X-ray diffraction analysis of metal-oxygen batteries allows to gain detailed understanding of the main reactions and side reactions; analyzing a solid electrolyte in a hot-press setup allows to monitor crystallization and stability during its synthesis. Since batteries are (electro)chemical reactors, the benefit of using the introduced operando techniques for classical reaction engineering is highlighted thereof.