Among the various energy-storage systems, lithium-ion capacitors (LICs) are receiving intensive attention due to their high energy density, high power density, long lifetime, and good stability. As a hybrid of lithium-ion batteries and supercapacitors, LICs are composed of a battery-type electrode and a capacitor-type electrode and can potentially combine the advantages of the high energy density of batteries and the large power density of capacitors. Here, the working principle of LICs is discussed, and the recent advances in LIC electrode materials, particularly activated carbon and lithium titanate, as well as in electrolyte development are reviewed. The charge-storage mechanisms for intercalative pseudocapacitive behavior, battery behavior, and conventional pseudocapacitive behavior are classified and compared. Finally, the prospects and challenges associated with LICs are discussed. The overall aim is to provide deep insights into the LIC field for continuing research and development of second-generation energy-storage technologies.

An innovative approach for efficient synthesis of petal-like molybdenum disulfide nanosheets inside hollow mesoporous carbon spheres (HMCSs), the yolk-shell structured MoS@C, has been developed. HMCSs effectively control and confine in situ growth of MoS nanosheets and significantly improve the conductivity and structural stability of the hybrid material. The yolk-shell structured MoS@C is proven to achieve high reversible capacity (993 mA h g at 1 A g after 200 cycles), superior rate capability (595 mA h g at a current density of 10 A g), and excellent cycle performance (962 mA h g at 1 A g after 1000 cycles and 624 mA h g at 5 A g after 400 cycles) when evaluated as an anode material for lithium-ion batteries. This superior performance is attributed to the yolk-shell structure with conductive mesoporous carbon as the shell and the stack of two-dimensional MoS nanosheets as the yolk.

This review summarizes the progress of pre-lithiation technologies involving the fundamental research and practical application of LICs.

Nanoparticle/MOF materials usually have new or enhanced applications compared with bare MOF or NPs.

Next‐generation Li‐ion batteries (LIBs) with higher energy density adopt some novel anode materials, which generally have the potential to exhibit higher capacity, superior rate performance as well as better cycling durability than conventional graphite anode, while on the other hand always suffer from larger active lithium loss (ALL) in the first several cycles. During the last two decades, various pre‐lithiation strategies are developed to mitigate the initial ALL by presetting the extra Li sources to effectively improve the first Coulombic efficiency and thus achieve higher energy density as well as better cyclability. In this progress report, the origin of the huge initial ALL of the anode and its effect on the performance of full cells are first illustrated in theory. Then, various pre‐lithiation strategies to resolve these issues are summarized, classified, and compared in detail. Moreover, the research progress of pre‐lithiation strategies for the representative electrochemical systems are carefully reviewed. Finally, the current challenges and future perspectives are particularly analyzed and outlooked. This progress report aims to bring up new insights to reassess the significance of pre‐lithiation strategies and offer a guideline for the research directions tailored for different applications based on the proposed pre‐lithiation strategies summaries and comparisons.

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Polyoxometalates (POMs) are a class of discrete molecular inorganic metal-oxide clusters with reversible multielectron redox capability. Taking advantage of their redox properties, POMs are thus expected to be directly involved in the lithium−sulfur batteries (Li−S, LSBs) system as a bidirectional molecular catalyst. Herein, we design a threedimensional porous structure of reduced graphene−carbon nanotube skeleton supported POM catalyst as a highconductive and high-stability host material. Based on various spectroscopic techniques and in situ electrochemical studies together with computational methods, the catalytic mechanism of POM clusters in Li−S battery was systematically clarified at the molecular level. The constructed POM-based sulfur cathode delivers a reversible capacity 1110 mAh g −1 at 1.0 C and cycling stability up to 1000 cycles at 3.0 C. Furthermore, Li−S pouch/ beaker batteries with a POM-based cathode were successfully demonstrated. This work provides essential inputs to promote molecular catalyst design and its application in LSBs.