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Developing efficient energy conversion and storage technology is gradually becoming more and more necessary with the increasing shortage of fuel resources and the growth of environmental pollution. Demand and applications for the emerging technology such as new-energy vehicles and massive-scale energy storage are also expanding. Therefore, new rechargeable batteries, especially the most promising electrochemical energy storage device, lithium-ion batteries (LIBs), play an important role on the energy storage stage. LIBs have achieved large-scale industrialization, while the various non-negligible problems still exist compared with the demand for the future. Significantly, most electrochemical reactions occur on the electrode-electrolyte interface, and interface components, surface structure and property determine the performance of batteries. Thus, numerous efforts have been made to form or modify the electrode-electrolyte interface. This article reviews recent research about surfaceinterface modification in electrodes and organic liquid electrolytes in LIBs. Specifically, the basic growth mechanism of electrolyte-electrode interface and SEI layer is referred. The summary and discussion of surface modification and the innovative design of SEI layer are mainly focused on. Finally, future research directions focusing on electrode-electrolyte interface for lithium storage are proposed.

Potassium-ion capacitor (PIC) is a new type of electrochemical energy storage device, and carbon-based materials are considered as one of the most promising candidate anode materials for K + storage. However, the migration rate of K + is slow and the material structure is easy to be damaged during the intercalation and de-intercalation processes because the K + has a larger radius, resulting in a significant decline in performance. Therefore, the development of low-cost carbon materials to meet the thermodynamic and kinetic requirements of K + diffusion has become the bottleneck of current development. In this work, the F and N co-doped porous carbon nanosheets (FNCPC) were prepared by direct high-temperature carbonization, in which the low-cost coal pitch as the carbon source, polytetrafluoroethylene as the fluorine source and sodium chloride as the template agent. The structure design of the nanosheet effectively shortens the transport path of ions, and the co-doping of F and N widens the layer spacing of carbon, alleviates the volume expansion problem, and also forms more surface defects, which provides more reactive sites for K + storage. In addition, electrochemical kinetic analysis and density functional theory (DFT) show that the FNCPC has remarkable pseudocapacitance characteristics and strong K adsorption energy. Benefiting from the synergistic optimization of structure and chemical properties, the FNCPC anode exhibits excellent potassium storage capacity (a high specific capacity of 212.8 mAh•g -1 at 2 A•g -1 ) and good cyclic stability. Furthermore, the PIC (AC//FNCPC) was constructed by using commercial activated carbon (AC) as cathode electrode and FNCPC as anode electrode, which