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Alkaline metal‐air batteries are advantageous in high voltage, low cost, and high safety. However, metal anodes are heavily eroded in strong alkaline electrolytes, causing serious side reactions including dendrite growth, passivation, and hydrogen evolution. To address this limitation, we successfully synthesized an organic N‐heterocycle compound (NHCC) to serve as an alternative anode. This compound not only exhibits remarkable stability but also possesses a low redox potential (−1.04 V vs. Hg/HgO) in alkaline environments. To effectively complement the low redox potential of the NHCC anode, we designed a dual‐salt highly concentrated electrolyte (4.0 M KOH+10.0 M KCF3SO3). This electrolyte expands the electrochemical stability window to 2.3 V through the robust interaction between the O atom in H2O molecule with the K+ of KCF3SO3 (H−O⋅⋅⋅KCF3SO3). We further demonstrated the K+ uptaken/extraction storage mechanism of NHCC anodes. Consequently, the alkaline aqueous NHCC anode‐air batteries delivers a high battery voltage of 1.6 V, high‐rate performance (101.9 mAh g−1 at 100 A g−1) and long cycle ability (30,000 cycles). Our work offers a molecular engineering strategy for superior organic anode materials and develops a novel double superconcentrated conductive salt electrolyte for the construction of high‐rate, long‐cycle alkaline aqueous organic anode‐air batteries. [ABSTRACT FROM AUTHOR]

The high thermodynamic instability and side reactions of Zn‐metal anode (ZMA), especially at high current densities, greatly impede the commercialization of aqueous zinc‐ion batteries (AZIBs). Herein, a fluorine‐rich double protective layer strategy is proposed to obtain the high reversibility of AZIBs through the introduction of a versatile tetradecafluorononane‐1,9‐diol (TDFND) additive in aqueous electrolyte. TDFND molecule with large adsorption energy (−1.51 eV) preferentially absorbs on the Zn anode surface to form a Zn(OR)2− (R=−CH2−(CF2)7−CH2−) cross‐linking complex network, which balances space electric field and controls the Zn2+ ion flux, thus enabling the uniform and compact deposition of Zn (002) crystal planes. Meanwhile, TDFND with low Lowest unoccupied molecular orbital (LUMO, 0.10 eV) energy level is priorly decomposed to regulate the interfacial chemistry of ZMA by building a ZnF2‐rich solid electrode/electrolyte interface (SEI) layer. It is found that a 14 nm‐thick SEI layer delivers excellent structural integrity to suppress parasitic reactions by blocking the direct contact of active water and ZMA. Consequently, the Zn electrode exhibits a superior cycling life over 430 h at 10 mA cm−2 and a high average Coulombic efficiency of 99.8 % at 5 mA cm−2. Furthermore, a 68 mAh pouch cell delivers 80.3 % capacity retention for 1000 cycles. [ABSTRACT FROM AUTHOR]

Sodium-ion hybrid capacitors (NIHC) with sodium ion battery type anodes and supercapacitor type cathodes are emerging as an attractive energy storage device due to the integration of high energy, high power and long lifetime. However, the battery type electrodes usually exhibit sluggish reaction kinetics than capacitor type cathodes due to slow Na ion insertion and extraction, which greatly hinders the rate performance. In this paper, carbon coated MoS 2 nanosheets are vertically grown on carbon cloth (CC) substrate using a hydrothermal reaction followed by calcination. The expanded interlayer distance of the MoS 2 ensures high ionic mobility while the highly conductive CC not only provides a self-supporting structure without the addition of insulative binder and additional conductive additive, but also effectively prevents the restacking of the MoS 2 sheets during cycling. Thus the architecture delivers a high area capacity of 0.511 mAh cm −2 at a current density of 0.2 mA cm −2 and a stable capacity retention of 83.3% after 200 cycles at 1 mA cm −2 . Furthermore, NIHC constructed with above anode delivers a high areal energy density of 1.22 mWh cm −2 at a power of 0.76 mW cm −2 , demonstrating an excellent energy-power delivery. [ABSTRACT FROM AUTHOR]

Tin dioxide (SnO 2) is a promising anode material for lithium-ion and sodium-ion batteries. However, the huge volume expansion during cycling makes it far away from practical application. Herein, we report a template-free "heterogeneous carbonization" strategy for fabricating SnO 2 /carbon/void/carbon nanofibers (SCVC) compound membrane with finite spatial domain in carbon matrix as buffer layer for volume changes of SnO 2. Reduced graphene oxide (rGO) is also imported into the SCVC membrane, acting as conductive binders to construct a free-standing SCVC-rGO electrode with exceptionally conductive network. The resultant SCVC-rGO anodes in lithium/sodium-ion batteries could deliver excellent electrochemical performances of higher reversible capacity, longer lifespan and superior rate capability. As lithium-ion battery anode, the SCVC-rGO electrode shows specific capacities of 950 mA h g−1 after 400 cycles at a current of 0.5 A g−1, and 824 mA h g−1 after 650 cycles at 1 A g−1. In sodium-ion batteries, the SCVC-rGO electrode gives rise to the specific capacity of 407 mA h g−1 after 2000 cycles at the current of 1 A g−1 with exceptional capacity retention. SnO 2 /carbon/void/carbon nanofibers membrane combined with reduced graphene oxide (SCVC-rGO) is constructed by a template free, one-step heterogeneous carbonization strategy. The internal void formed in situ in SnO 2 /C can be used as confined space to accommodate its volume expansion, while the residual ultrathin carbon layer on SnO 2 nanocrystals can prevent their amalgamation and recrystallization. The SCVC-rGO anodes exhibit excellent cycling stability and rate capability in LIBs and SIBs. [Display omitted] • One-step strategy of heterogenous carbonization to in-situ form buffering voids. • Based on the different carbon yields from various precursors and without the help of templates and corrosives. • Internal voids and residual ultrathin carbon layer ensure the complete reversibility of electrochemical reactions. • Excellent cycling stability and rate capability in half cells of LIBs and SIBs have been achieved. [ABSTRACT FROM AUTHOR]