Electrochemistry-Driven Interphase Doubly Protects Graphite Cathodes for Ultralong Life and Fast Charge of Dual-Ion Batteries.

Dual-ion batteries (DIBs) with graphite as cathode material, show superiority in terms of sustainability, affordability, and environmental impact over Li-ion batteries that rely on transition-metal based cathodes. However, graphite cathodes severely suffer from poor structural stability during anion storage at high potentials because of the co-intercalation and oxidative decomposition of electrolytes. This work presents an in situ electrochemistry-driven route to create a bifunctional interphase through implantation of diethylenetriaminepenta(methylene-phosphonic acid) (DTPMP) on the surface of graphite particles.

Ultrafast Charge and Long Life of High-Voltage Cathodes for Dual-Ion Batteries via a Bifunctional Interphase Nanolayer on Graphite Particles.

Dual-ion batteries (DIBs) with Co/Ni-free cathodes especially graphite cathodes are very attractive energy storage systems in the long run because of the cost effectiveness and sustainability. However, graphite cathodes severely suffer from poor structural stability during anions storage at high potentials owing to the oxidative decomposition of electrolytes and volume expansion. This work proposes an artificial cathode/electrolyte interphase (CEI) strategy by implanting polyphosphoric acid (PPA) nanofilms tightly on natural graphite (NG) particles via interfacial hydrogen bonding.

Electrolyte Design Enabling a High-Safety and High-Performance Si Anode with a Tailored Electrode-Electrolyte Interphase.

Silicon (Si) anodes are advantageous for application in lithium-ion batteries in terms of their high theoretical capacity (4200 mAh g ), appropriate operating voltage (<0.4 V vs Li/Li ), and earth-abundancy. Nevertheless, a large volume change of Si particles emerges with cycling, triggering unceasing breakage/re-formation of the solid-electrolyte interphase (SEI) and thereby the fast capacity degradation in traditional carbonate-based electrolytes.

In Situ Transformed Solid Electrolyte Interphase by Implanting a 4-Vinylbenzoic Acid Nanolayer on the Natural Graphite Surface.

A solid electrolyte interphase (SEI) layer on a graphite anode plays a crucial role in deciding electrochemical properties of the electrode including the first Coulombic efficiency, rate capability, operating temperature, and long-term cycling stability. However, the ultrathin functional SEI layer is always naturally grown via electrolyte reduction decomposition reactions. Herein, we report a new strategy of in situ transformed solid electrolyte interphase of high stability by implanting a 4-vinylbenzoic acid (4-VBA) nanolayer on a mildly oxidized graphite surface.

Simultaneously formed and embedding-type ternary MoSe/MoO/nitrogen-doped carbon for fast and stable Na-ion storage.

To obtain an electrode material that is capable of manifesting high Na-ion storage capacity during long-term cycling at a rapid discharge/charge rate, ternary heterophases MoSe/MoO/carbon are rationally designed and synthesized through a supermolecule-assisted strategy. Through using supermolecules that are constructed from MoO and polydopamine as the precursor and sulfonated polystyrene microspheres as the sacrificial template, the formed ternary phases MoSe/MoO/carbon are fabricated into a hollow microspherical structure, which is assembled from ultrathin nanosheets with MoSe and MoO nanocrystallites strongly embedded in a nitrogen-doped carbon matrix. In the ternary phases, the MoSe phase contributes to a high Na-ion storage capacity by virtue of its layered crystalline structure with a wide interlayer space, while the surrounding MoO and porous nitrogen-doped carbon phases are conducive to rate behaviour and cycling stability of the ternary hybrids since both the two phases are beneficial for electronic transport and structural stability of MoSe during repeated sodiation/desodiation reaction.

Dimethylacrylamide, a novel electrolyte additive, can improve the electrochemical performances of silicon anodes in lithium-ion batteries.

To enhance the electrochemical properties of silicon anodes in lithium-ion batteries, dimethylacrylamide (DMAA) was selected as a novel electrolyte additive. The addition of 2.5 wt% DMAA to 1.

Quantitative Characterization of the Surface Evolution for LiNiCoMnO/Graphite Cell during Long-Term Cycling.

Many factors have been brought forward to explain the capacity degradation mechanisms of LiNiCoMnO (NCM)/graphite cells at extreme conditions such as under high temperature or with high cutoff voltage. However, the main factors dominating the long-term cycling performance under normal operations remain elusive. Quantitative analyses of the electrode surface evolution for a commercial 18650 LiNiCoMnO (NCM523)/graphite cell during ca.

3D Interconnected and Multiwalled Carbon@MoS @Carbon Hollow Nanocables as Outstanding Anodes for Na-Ion Batteries.

Currently, the specific capacity and cycling performance of various MoS /carbon-based anode materials for Na-ion storage are far from satisfactory due to the insufficient structural stability of the electrode, incomplete protection of MoS by carbon, difficult access of electrolyte to the electrode interior, as well as inactivity of the adopted carbon matrix. To address these issues, this work presents the rational design and synthesis of 3D interconnected and hollow nanocables composed of multiwalled carbon@MoS @carbon. In this architecture, (i) the 3D nanoweb-like structure brings about excellent mechanical property of the electrode, (ii) the ultrathin MoS nanosheets are sandwiched between and doubly protected by two layers of porous carbon, (iii) the hollow structure of the primary nanofibers facilitates the access of electrolyte to the electrode interior, (iv) the porous and nitrogen-doping properties of the two carbon materials lead to synergistic Na-storage of carbon and MoS .

Layer-by-Layer Polyelectrolyte Assisted Growth of 2D Ultrathin MoS2 Nanosheets on Various 1D Carbons for Superior Li-Storage.

Transitional metal sulfide/carbon hybrids with well-defined structures could not only maximize the functional properties of each constituent but engender some unique synergistic effects, holding great promise for applications in Li-ion batteries and supercapacitors and for catalysis. Herein, a facile and versatile approach is developed to controllably grow 2D ultrathin MoS2 nanosheets with a large quantity of exposed edges onto various 1D carbons, including carbon nanotubes (CNTs), electrospun carbon nanofibers, and Te-nanowire-templated carbon nanofibers. The typical approach involves the employment of layer-by-layer (LBL) self-assembled polyelectrolyte, which controls spatially the uniform growth and orientation of ultrathin MoS2 nanosheets on these 1D carbons irrespective of their surface properties.

Synergistic Ternary Composite (Carbon/Fe3 O4 @Graphene) with Hollow Microspherical and Robust Structure for Li-Ion Storage.

The electrode materials with hollow structure and/or graphene coating are expected to exhibit outstanding electrochemical performances in energy-storage systems. 2D graphene-wrapped hollow C/Fe3 O4 microspheres are rationally designed and fabricated by a novel facile and scalable strategy. The core@double-shell structure SPS@FeOOH@GO (SPS: sulfonated polystyrene, GO: graphene oxide) microspheres are first prepared through a simple one-pot approach and then transformed into C/Fe3 O4 @G (G: graphene) after calcination at 500 °C in Ar.

From Dispersed Microspheres to Interconnected Nanospheres: Carbon-Sandwiched Monolayered MoS2 as High-Performance Anode of Li-Ion Batteries.

Hierarchical structured carbon@MoS2 (C@MoS2) microspheres and nanospheres composed of carbon-sandwiched monolayered MoS2 building blocks are synthesized through a facile one-pot polyvinylpyrrolidone (PVP) micelle-assisted hydrothermal route. The dimension and carbon content of C@MoS2 spheres are effectively controlled by singly adjusting the concentration of PVP, which plays the dual functions of soft-template and carbon source. As the anode materials of Li-ion batteries, C@MoS2 nanospheres present considerably higher capacity, better rate behavior and cycling stability than C@MoS2 microspheres.

Is overprotection of the sulfur cathode good for Li-S batteries?

How to restrain the dissolution of polysulfides from the sulfur cathode is the current research focus of Li-S batteries. Here, we find that moderate dissolution of polysulfides is of great importance for high-efficiency and stable discharge/charge cycling. Both overprotection and inadequate protection of the sulfur cathode are unfavorable for the cycling of Li-S batteries.

Core-shell structure of hierarchical quasi-hollow MoS2 microspheres encapsulated porous carbon as stable anode for Li-ion batteries.

Monodisperse sulfonated polystyrene (SPS) microspheres are employed as both the template and carbon source to prepare MoS2 quasi-hollow microspheres-encapsulated porous carbon. The synthesis procedure involves the hydrothermal growth of MoS2 ultrathin nanosheets on the surface of SPS microspheres and subsequent annealing to remove SPS core. Incomplete decomposition of SPS during annealing due to the confining effect of MoS2 shells leaves residual porous carbon in the interior.

Low-cost synthesis of hierarchical V2O5 microspheres as high-performance cathode for lithium-ion batteries.

Hierarchical V2O5 microspheres composed of stacked platelets are fabricated through a facile, low-cost, and energy-saving approach. The preparation procedure involves a room-temperature precipitation of precursor microspheres in aqueous solution and subsequent calcination. Because of this unique structure, V2O5 microspheres manifest a high capacity (266 mA h g(-1)), excellent rate capability (223 mA h g(-1) at a current density 2400 mA g(-1)), and good cycling stability (200 mA h g(-1) after 100 cycles) as cathode materials for lithium-ion batteries.

An aqueous rechargeable lithium battery of high energy density based on coated Li metal and LiCoO2.

Using a coated Li metal as an anode and LiCoO2 as a cathode, an aqueous rechargeable battery is built up, whose average discharge voltage is 3.70 V. This high voltage stability is due to the "cross-over" effect of Li(+) ions, which is different from the traditional ways of increasing overpotentials.

Core-shell sulfur@polypyrrole composites as high-capacity materials for aqueous rechargeable batteries.

In order to explore the potential application of sulfur in aqueous rechargeable batteries, core-shell sulfur-polypyrrole (S@PPy) composites were prepared through a novel one-pot and surfactant-free method. Sulfur exhibits a very high capacity of 473 mA h g(-1) and good cycling stability in an aqueous Li(2)SO(4) electrolyte due to the polypyrrole coating.

2D sandwich-like sheets of iron oxide grown on graphene as high energy anode material for supercapacitors.

2D sandwich-like sheets of iron oxide grown on graphene as high energy anode material for supercapacitors are prepared from the direct growth of FeOOH nanorods on the surface of graphene and the subsequent electrochemical transformation of FeOOH to Fe(3)O(4). The Fe(3)O(4) @RGO nanocomposites exhibit superior capacitance (326 F g(-1)), high energy density (85 Wh kg(-1)), large power, and good cycling performance in 1 mol L(-1) LiOH solution.