Why nanoelectrochemistry is necessary in battery research?

The active materials constitute the heart of any battery so that unambiguous determination of their intrinsic properties is of essential importance to achieve progress in battery research. A variety of in situ techniques with high lateral resolution has been developed or adapted for battery research. Surprisingly, nanoelectrochemistry is not attracting sufficient attention from the battery community despite the existing examples of relevant in situ and highly resolved spatiotemporal information. Herein, the important role of nanoelectrochemistry in battery research is highlighted to help encourage its use in this field. In the first part, two examples in which the use of nanoelectrochemistry is a must are provided, that is, determination of intrinsic kinetics of active materials and understanding of relationships between particle structure and electrochemical activity. In the second part, pros and cons of three mature nanoelectrochemistry techniques in battery research, that is, particle-on-a-stick measurements, nanoimpact measurements, and scanning electrochemical probe microscopy, are discussed providing representative examples.Spanish Government (MINECO) through the Research Challenges Programme (grant RTI2018-099228-A-I00) and Ramón y Cajal award (RYC2018-026086-I) as well as the NanoBat project. NanoBat has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement no. 861962