Coordination compounds in lithium storage and lithium-ion transport

Abstract

Lithium-ion batteries (LIBs) have enabled wireless revolution of portable digital products. However, for high-performance applications such as large-scale energy storage and next-generation portable devices, the energy and power densities as well as the cycle life of LIBs still need to be further enhanced. This can be realized by improving the electrochemical performance of the three main components of LIBs: cathode, anode, and electrolyte. In addition to LIBs, lithium–metal batteries (LMBs) have also attracted considerable attention owing to their ultra-high energy density arising from the lithium–metal anode. However, LMB performance is currently limited by dendrite formation and poor interfacial contact between electrode and electrolyte. Herein we highlight the applications of coordination chemistry in LIBs and LMBs, especially for realization of promising next-generation electrode and electrolyte materials based on coordination compounds with well-defined molecular structures. We start by introducing the development of coordination chemistry from discrete coordination compounds to coordination polymers and metal–organic frameworks. Then, we present the design strategies of coordination compounds for lithium storage and lithium-ion transport. Approaches to enhance the electrochemical properties, working potential, capacity, cycling stability, and rate capability of coordination compound-based electrodes are discussed in detail. The reticular chemistry endowing metal–organic frameworks with desired structures and pore metrics as electrolytes for lithium-ion transmission is also summarized. Finally, the current challenges and promising research directions of coordination chemistry for LIBs and LMBs are presented.