Lithium-ion batteries (LiBs) are recognized as the most rapidly growing energy storage technology. To improve the energy and power density of LiBs, tremendous progress has been made in every battery component. In this review, we focus on the investigations of electrolyte and electrode designs aimed at understanding and enhancing ion transport properties to improve the performance of LiBs. Theoretical, computational, and experimental studies of the importance of transport properties are highlighted, and the efforts to enhance the lithium transference number in organic electrolytes is discussed. We also review the significant ion transport challenges in porous electrodes and the demonstrated examples of advanced, high power/energy density electrodes. Overall, we focus on the most recent and pioneering works in terms of complex electrolytes with high transport properties and thick porous electrodes for high performance LiBs. This review intends to provide guidance for development of advanced electrolytes and electrodes for high performance LiBs through comprehensive compilation of prior understanding via experimental, computational, and theoretical points of view.

To improve the energy density of lithium-ion batteries, the development of advanced electrolytes with enhanced transport properties is highly important. Here, we show that by confining the conventional electrolyte (1 M LiPF6 in EC-DEC) in a microporous polymer network, the cation transference number increases to 0.79 while maintaining an ionic conductivity on the order of 10−3 S cm−1. By comparison, a non-porous, condensed polymer electrolyte of the same chemistry has a lower transference number and conductivity, of 0.65 and 7.6 × 10−4 S cm−1, respectively. Within Li-metal/LiFePO4 cells, the improved transport properties of the porous polymer electrolyte enable substantial performance enhancements compared to a commercial separator in terms of rate capability, capacity retention, active material utilization, and efficiency. These results highlight the importance of polymer electrolyte structure–performance property relationships and help guide the future engineering of better materials.

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