Dear Colleagues,

There is a strong need to enhance both the energy and power density of energy storage devices, especially in the fields of portable devices and transportation. Recently, Li-ion capacitors (LICs) have been attracting attention as energy storage devices which can compensate for the low power density and short cycle life of existing Li-ion batteries and for the low energy density of electric double-layer capacitors. LICs are categorized as hybrid capacitors, in which non-faradaic processes generating the electric double layer proceed on the cathode, and faradaic reactions occur within the anode through Li-ion insertion/extraction. Since the development of coin-type LICs by Kanebo in 1991 and the development of 1000 F-class high-capacitance LICs by Fuji Heavy Industries (now Subaru) in 2005, academia and industrial sectors have been intensively performing R&D. It is now an appropriate time to publish a Special Issue targeting recent developments and reviewing the technological trends and market penetration of LICs.

In addition to the wide variety in material selections of cathode and anode active materials, binders, electrolytes and separators, LICs have various device factors such as the mass ratio of cathode and anode active materials, anode pre-lithiation (pre-doping of Li ions) level and working cell voltage range that significantly influence their charge–discharge performances and lifetimes. Field experiences with LICs embedded in systems of the electronic device, transportation, robotics and machinery sectors are now highly needed to be published in order to share knowledge on their actual performances. The journal Batteries invites contributions to this Special Issue featuring recent technological developments in LICs from the aspect of materials, devices and systems. Review articles regarding LIC technology are also welcome.

Topics of interest include, but are not limited to, the following:

• Performance enhancement of LICs by using novel materials (cathode and anode active materials, conductive agents, binders, current collectors, electrolytes, separators, etc.) and by device optimization (electrode design, pre-lithiation strategy, cell assembly and packaging methodology, etc.);
• Material and electrochemical studies towards device components intended for use in LICs;
• Working mechanism studies of LICs in various working conditions (high and low temperatures, excessive charging and discharging, etc.);
• Aging behavior and modeling of LICs in various working conditions;
• Diagnosis or monitoring technology of LICs;
• Case studies of prototypes or commercial LICs used in industrial applications such as electronic devices and vehicles, and in special environments;
• Hybridization of LICs with other types of energy devices such as secondary batteries and fuel cells.

Prof. Dr. Seiji Kumagai
Guest Editor

Manuscript Submission Information

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• lithium-ion capacitors
• electrochemical capacitors
• hybrid capacitors
• electrode
• electrolyte
• pre-lithiation
• energy density
• power density
• lifetime
• aging
• diagnosis
• monitoring