The exploration of new and efficient energy storage mechanisms through nanostructured electrode design is crucial for the development of high‐performance rechargeable batteries. Herein, black phosphorus quantum dots (BPQDs) and Ti3C2 nanosheets (TNSs) are employed as battery and pseudocapacitive components, respectively, to construct BPQD/TNS composite anodes with a novel battery‐capacitive dual‐model energy storage (DMES) mechanism for lithium‐ion and sodium‐ion batteries. Specifically, as a battery‐type component, BPQDs anchored on the TNSs are endowed with improved conductivity and relieved stress upon cycling, enabling a high‐capacity and stable energy storage. Meanwhile, the pseudocapacitive TNS component with further atomic charge polarization induced by POTi interfacial bonds between the two components allows enhanced charge adsorption and efficient interfacial electron transfer, contributing a higher pseudocapacitive value and fast energy storage. The DMES mechanism is evidenced by substantial characterizations of X‐ray photoelectron spectroscopy and X‐ray absorption fine structure spectroscopy, density functional theory calculations, and kinetics analyses. Consequently, the composite electrode exhibits superior battery performance, especially for lithium storage, such as high capacity (910 mAh g−1 at 100 mA g−1), long cycling stability (2400 cycles with a capacity retention over 100%), and high rate capability, representing the best comprehensive battery performance in BP‐based anodes to date.

The intercalation strategy has become crucial for 2D layered materials to achieve desirable properties, however, the intercalated guests are often limited to metal ions or small molecules. Here, we develop a simple, mild and efficient polymer-direct-intercalation strategy that different polymers (polyethyleneimine and polyethylene glycol) can directly intercalate into the MoS2 interlayers, forming MoS2-polymer composites and interlayer-expanded MoS2/carbon heteroaerogels after carbonization. The polymer-direct-intercalation behavior has been investigated by substantial characterizations and molecular dynamic calculations. The resulting composite heteroaerogels possess 3D conductive MoS2/C frameworks, expanded MoS2 interlayers (0.98 nm), high MoS2 contents (up to 74%) and high Mo valence (+6), beneficial to fast and stable charge transport and enhanced pseudocapacitive energy storage. Consequently, the typical MoS2/N-doped carbon heteroaerogels exhibit outstanding supercapacitor performance, such as ultrahigh capacitance, remarkable rate capability and excellent cycling stability. This study offers a new intercalation strategy which may be generally applicable to 2D materials for promising energy applications.

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Polypyrrole-coated multiwalled carbon nanotubes (PPy-MWCNT) were used for the fabrication of activated carbon-coated MWCNT doped with nitrogen (N-AC-MWCNT). The conceptually new method for the fabrication of non-agglomerated PPy-MWCNT with good coating uniformity allowed the fabrication of uniform and welldispersed N-AC-MWCNT with high surface area. The use of N-AC-MWCNT allowed the fabrication of supercapacitor electrodes with high mass loading in the range of 15−35 mg cm −2 and with a high active material to current collector mass ratio of 0.21−0.50. The N-AC-MWCNT electrodes showed excellent electrochemical performance in aqueous 0.5 M Na 2 SO 4 electrolyte. The maximum specific capacitance of 3.6 F cm −2 (103.1 F g −1 ) was achieved for mass loading of 35 mg cm −2 at a scan rate of 2 mV s −1 . The aqueous supercapacitor cells, based on N-AC-MWCNT electrodes, exhibited excellent performance with energy density of 16.1 mWh g −1 , power density of 14.4 W g −1 , and enlarged voltage window of 1.8 V. The individual electrodes and cells showed good capacitance retention at high charge−discharge rates and good cycling stability. Moreover, the N-AC-MWCNT electrodes showed promising performance for capacitive deionization of water. The feasibility of capacitive removal of organic dyes from aqueous solutions has been demonstrated. A quartz crystal microbalance method was used as a tool for the analysis of electrosorption and electrodesorption of ions and charged dyes during charge and discharge.

The exploration of ideal electrode materials overcoming the critical problems of large electrode volume changes and sluggish redox kinetics induced by large ionic radius of Na+/K+ ions is highly desirable for sodium/potassium‐ion batteries (SIBs/PIBs) toward large‐scale applications. The present work demonstrates that single‐phase ternary cobalt phosphoselenide (CoPSe) in the form of nanoparticles embedded in a layered metal–organic framework (MOF)‐derived N‐doped carbon matrix (CoPSe/NC) represents an ultrastable and high‐rate anode material for SIBs/PIBs. The CoPSe/NC is fabricated by using the MOF as both a template and precursor, coupled with in situ synchronous phosphorization/selenization reactions. The CoPSe anode holds a set of intrinsic merits such as lower mechanical stress, enhanced reaction kinetics, as well as higher theoretical capacity and lower discharge voltage relative to its counterpart of CoSe2, and suppressed shuttle effect with higher intrinsic electrical conductivity relative to CoPS. The involved mechanisms are evidenced by substantial characterizations and density functional theory (DFT) calculations. Consequently, the CoPSe/NC anode shows an outstanding long‐cycle stability and rate performance for SIBs and PIBs. Moreover, the CoPSe/NC‐based Na‐ion full cell can achieve a higher energy density of 274 Wh kg−1, surpassing that based on CoSe2/NC and most state‐of‐the‐art Na‐ion full cells based on P‐, Se‐, or S‐containing binary/ternary anodes to date.