Materials’ Methods: NMR in Battery Research

Abstract

Improving electrochemical energy storage is one of the major issues of our time. The search for new battery materials together with the drive to improve performance and lower cost of existing and new batteries is not without its challenges. Success in these matters is undoubtedly based on first understanding the underlying chemistries of the materials and the relations between the components involved. A combined application of experimental and theoretical techniques has proven to be a powerful strategy to gain insights into many of the questions that arise from the "how do batteries work and why do they fail" challenge. In this Review, we highlight the application of solid-state nuclear magnetic resonance (NMR) spectroscopy in battery research: a technique that can be extremely powerful in characterizing local structures in battery materials, even in highly disordered systems. An introduction on electrochemical energy storage illustrates the research aims and prospective approaches to reach these. We particularly address "NMR in battery research" by giving a brief introduction to electrochemical techniques and applications as well as background information on both in and ex situ solid-state NMR spectroscopy. We will try to answer the question "Is NMR suitable and how can it help me to solve my problem?" by shortly reviewing some of our recent research on electrodes, microstructure formation, electrolytes and interfaces, in which the application of NMR was helpful. Finally, we share hands-on experience directly from the lab bench to answer the fundamental question "Where and how should I start?" to help guide a researcher's way through the manifold possible approaches.

In Situ Stripline Electrochemical NMR for Batteries

“…Nuclear magnetic resonance (NMR) spectroscopy possesses unique investigative advantages in unraveling details of local structure and dynamic battery chemistries, and its application has long been recognized and actively pursued in both ex‐situ and in situ approaches. In the latter, notwithstanding some impressive progress achieved recently,,, a few perennial technical challenges still exist. First, intrinsic incompatibility between traditional coil‐based NMR detection and the conducting materials of the electrodes necessary for a working battery metallic electrodes deteriorates the already low mass‐detection sensitivity of NMR .…”

Correlating Structure and Properties of Super‐Concentrated Electrolyte Solutions: 17O NMR and Electrochemical Characterization

“…In order to deeply investigate the processes occurring in the novel electrochemical energy storage systems based on lithium metal anode, the combination of electrochemical techniques with bulk and advanced spectroscopic ones is mandatory. In this context, nuclear magnetic resonance (NMR) spectroscopy plays a key role to understand the processes taking place in a battery . NMR exploits the magnetic properties of atomic nuclei to find out information on the chemical environment in molecules and solids, as well as on its changes over time.…”

Novel Methods for Sodium‐Ion Battery Materials

“…Combining with magic‐angle spinning (MAS), it can present a high experimental resolution for ex situ solid‐state experiments, which has been applied to different parts of electrochemical batteries. A recent review about NMR in battery research gave a systematic introduction to electrochemical techniques and applications as well as background information on both in situ and ex situ ss‐NMR spectroscopy, which will not be repeated here . Clement et al studied the electrochemical performance and structural stability of Mg‐doped Na 2/3 Mn 1− y Mg y O 2 ( y = 0.0, 0.05, 0.1) cathodes by ex situ ss‐NMR .…”

“…Galvanostatic/chronopotentiometric methods are commonly used to determine the measurable information regarding electrochemical performance evaluation and composition–structural properties of the battery components. With respect to the electrochemical methods, several recent reviews have made larger contributions to the groundwork for the discussions, and these are recommended to readers for related content . Experimental techniques for NIB materials based on the relationships between the properties and performances shown in Figure can be roughly classified into four parts: structure‐related techniques, composition‐related techniques, size‐ and morphology‐related techniques, and surface‐ and interface‐related techniques, which are summarized in Table 1 .…”