In situ/operando synchrotron-based X-ray techniques for lithium-ion battery research

Lithium-ion battery (LIB) technology is the most attractive technology for energy storage systems in today’s market. However, further improvements and optimizations are still required to solve challenges such as energy density, cycle life, and safety. Addressing these challenges in LIBs requires a fundamental understanding of the reaction mechanisms in various physical/chemical processes during LIB operation. Advanced in situ/operando synchrotron-based X-ray characterization techniques are powerful tools for providing valuable information about the complicated reaction mechanisms in LIBs. In this review, several state-of-the-art in situ/operando synchrotron-based X-ray techniques and their combination with other characterization tools for battery research are introduced. Various in situ cell configurations and practical operating tips for cell design and experimental set-ups are also discussed. The mechanisms that shorten lithium-ion battery lifetimes and cause safety issues can be identified using advanced x-ray light source at National Synchrotron Light Source II. Xiao-Qing Yang from Brookhaven National Laboratory in the USA and Xiqian Yu at the Chinese Academy of Science in Beijing review efforts to look inside working batteries using synchrotron-generated X-rays with a specially designed in situ cell. These experiments can record the changes of lithium battery electrodes, such as the evolution of structures as the battery during charge-discharge by x-ray diffraction (XRD) and the complementary techniques including X-ray absorption spectroscopy, which can pinpoint the individual element responsible for improving the battery’s performance and lifetime. Testing battery with different electrochemical history can be removed and re-inserted into the synchrotron beam to track individual nanostructures as the battery cycles and ages. Advanced in situ/operando synchrotron based X-ray characterization techniques are powerful tools in providing valuable information about the complicate reaction mechanisms in lithium-ion batteries. In this review, the state-of-the-art of in situ/operando synchrotron-based X-ray techniques and their combination for battery research are introduced. Various types of in situ cell designs and practical operation tips for experimental set ups are also discussed.