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The zinc anode mainly faces technical problems such as short circuits caused by the growth of dendrite, low coulomb efficiency, and a short cycle life caused by side reactions, which impedes the rapid development of aqueous zinc-ion batteries (AZIBs). Herein, a common ionic liquid, 1,1-Spirobipyrrolidinium tetrafluoroborate ([SBP]BF4), is selected as a new additive for pure ZnSO4 electrolyte. It is found that this additive could regulate the solvation sheath of hydrated Zn2+ ions, promote the ionic mobility of Zn2+, homogenize the flux of Zn2+, avoid side reactions between the electrolyte and electrode, and inhibit the production of zinc dendrites by facilitating the establishment of an inorganic solid electrolyte interphase layer. With the 1% [SBP]BF4-modified electrolyte, the Zn||Zn symmetric cell delivers an extended plating/stripping cycling life of 2000 h at 1 mA cm−2, which is much higher than that of the cell without additives (330 h). As a proof of concept, the Zn‖V2O5 battery using the [SBP]BF4 additive shows excellent cycling stability, maintaining its specific capacity at 97 mAh g−1 after 2000 cycles at 5 A g−1, which is much greater than the 46 mAh g−1 capacity of the non-additive battery. This study offers zinc anode stabilization through high-efficiency electrolyte engineering. [ABSTRACT FROM AUTHOR]

Similar to lithium‐ion batteries (LIBs), during the first charge/discharge process of lithium‐ion capacitors (LICs), lithium‐intercalated anodes (e.g., silicon, graphite, and hard carbon) also exhibit irreversible lithium intercalation behaviors, such as the formation of a solid electrolyte interface (SEI), which will consume Li+ in the electrolyte and significantly reduce the electrochemical performance of the system. Therefore, pre‐lithiation is an indispensable procedure for LICs. At present, commercial LICs mostly use lithium metal as the lithium source to compensate for the irreversible capacity loss, which has the demerits of operational complexity and danger. However, the pre‐lithiation strategy based on cathode sacrificial lithium salts (CSLSs) has been proposed, which has the advantages of low cost, simple operation, environmental protection, and safety. Therefore, there is an urgent need for a timely and comprehensive summary of the application of CSLSs to LICs. In this review, the important roles of pre‐lithiation in LICs are detailed, and different pre‐lithiation methods are reviewed and compared systematically and comprehensively. After that, we systematically discuss the pre‐lithiation strategies based on CSLSs and mainly introduce the lithium extraction mechanism of CSLSs and the influence of intrinsic characteristics and doping amount of CSLSs on LICs performance. In addition, a summary and outlook are conducted, aiming to provide the essential basic knowledge and guidance for developing a new pre‐lithiation technology. [ABSTRACT FROM AUTHOR]

Owing to their unique nanosize effect and surface effect, pseudocapacitive quantum dots (QDs) hold considerable potential for high‐efficiency supercapacitors (SCs). However, their pseudocapacitive behavior is exploited in aqueous electrolytes with narrow potential windows, thereby leading to a low energy density of the SCs. Here, a film electrode based on dual‐confined FeOOH QDs (FQDs) with superior pseudocapacitive behavior in a high‐voltage ionic liquid (IL) electrolyte is put forward. In such a film electrode, FQDs are steadily dual‐confined in a 2D heterogeneous nanospace supported by graphite carbon nitride (g‐C3N4) and Ti‐MXene (Ti3C2). Probing of potential‐driven ion accumulation elucidates that strong adsorption occurs between the IL cation and the electrode surface with abundant active sites, providing sufficient redox reaction of FQDs in the film electrode. Furthermore, porous g‐C3N4 and conductive Ti3C2 act as ion‐accessible channels and charge‐transfer pathways, respectively, endowing the FQDs‐based film electrode with favorable electrochemical kinetics in the IL electrolyte. A high‐voltage flexible SC (FSC) based on an ionogel electrolyte is fabricated, exhibiting a high energy density (77.12 mWh cm−3), a high power density, a remarkable rate capability, and long‐term durability. Such an FSC can also be charged by harvesting sustainable energy and can effectively power various wearable and portable electronics. [ABSTRACT FROM AUTHOR]

Large Li 2 O 2 aggregations can produce high-capacity of lithium oxygen (Li-O 2 ) batteries, but the larger ones usually lead to less-efficient contact between Li 2 O 2 and electrode materials. Herein, a hierarchical cathode architecture based on different discharge characteristics of α-MnO 2 and Co 3 O 4 is constructed, which can enable the embedded growth of large Li 2 O 2 aggregations to solve this problem. Through experimental observations and first-principle calculations, it is found that α-MnO 2 nanorod tends to form uniform Li 2 O 2 particles due to its preferential Li + adsorption and similar LiO 2 adsorption energies of different crystal faces, whereas Co 3 O 4 nanosheet tends to simultaneously generate Li 2 O 2 film and Li 2 O 2 nanosheets due to its preferential O 2 adsorption and different LiO 2 adsorption energies of varied crystal faces. Thus, the composite cathode architecture in which Co 3 O 4 nanosheets are grown on α-MnO 2 nanorods can exhibit extraordinary synergetic effects, i.e., α-MnO 2 nanorods provide the initial nucleation sites for Li 2 O 2 deposition while Co 3 O 4 nanosheets provide dissolved LiO 2 to promote the subsequent growth of Li 2 O 2 . Consequently, the composite cathode achieves the embedded growth of large Li 2 O 2 aggregations and thus exhibits significantly improved specific capacity, rate capability, and cyclic stability compared with the single metal oxide electrode.