Steric Hindrance Engineering to Modulate the Closed Pores Formation of Polymer-Derived Hard Carbon for High-Performance Sodium-Ion Batteries.

The closed pores play a critical role in improving the sodium storage capacity of hard carbon (HC) anode, however, their formation mechanism as well as the efficient modulation strategy at molecular level in the polymer-derived HCs is still lacking. In this work, the steric hindrance effect has been proposed to create closed pores in the polymer-derived HCs for the first time through grafting the aromatic rings within and between the main chains in the precursor. The experimental data and theoretical calculation demonstrate that steric-hindrance effect from the aromatic ring side group can increase backbone rigidity and the internal free volumes in the polymer precursor, which can prevent the over graphitization and facilitate the formation of closed pores during the carbonization process.

Fast-charging anodes for lithium ion batteries: progress and challenges.

Slow charging speed has been a serious constraint to the promotion of electric vehicles (EVs), and therefore the development of advanced lithium-ion batteries (LIBs) with fast-charging capability has become an urgent task. Thanks to its low price and excellent overall electrochemical performance, graphite has dominated the anode market for the past 30 years. However, it is difficult to meet the development needs of fast-charging batteries using graphite anodes due to their fast capacity degradation and safety hazards under high-current charging processes.

Organic Nitrate Additive for High-Rate and Large-Capacity Lithium Metal Anode in Carbonate Electrolyte.

Lithium nitrate has been widely used to improve the interfacial stability of Li metal anode in ether electrolyte. However, the low solubility limits its application in carbonate electrolytes for high-voltage Li metal batteries. Herein, nitrated polycaprolactone (PCL-ONO ), which is prepared via the acylation of polycaprolactone diol (PCL-diol) followed by the grafting of nitrate group, has been proposed as an electrolyte additive to introduce high-concentration NO into carbonate electrolytes for the first time.

Competitive Redox Chemistries in Vanadium Niobium Oxide for Ultrafast and Durable Lithium Storage.

Niobium pentoxide (NbO) anodes have gained increasing attentions for high-power lithium-ion batteries owing to the outstanding rate capability and high safety. However, NbO anode suffers poor cycle stability even after modified and the unrevealed mechanisms have restricted the practical applications. Herein, the over-reduction of Nb has been demonstrated to be the critical reason for the capacity loss for the first time.

Dynamic gel as artificial interphase layer for ultrahigh-rate and large-capacity lithium metal anode.

Constructing a stable artificial solid-electrolyte interphase has become one of the most effective strategies to overcome the poor reversibility of lithium metal anode, yet the protection role is still insufficient at elevated current densities over 10 mA cm and large areal capacities over 10 mAh cm. Herein, we propose a dynamic gel with reversible imine groups, which is prepared via a cross linking reaction between flexible dibenzaldehyde-terminated telechelic poly(ethylene glycol) and rigid chitosan, to fabricate a protective layer for Li metal anode. The as-prepared artificial film shows combined merits of high Young's modulus, strong ductility and high ionic conductivity.

Black phosphorus stabilized by titanium disulfide and graphite via chemical bonds for high-performance lithium storage.

Black phosphorus (BP) anode has received extensive attentions for lithium-ion batteries (LIBs) due to its ultrahigh theoretical specific capacity (2596 mAh g) and superior electronic conductivity (≈10 S m). However, the enormous volume variations during lithiation/delitiation processes greatly limit its applications. Herein, a new BP-titanium disulfide-graphite (BP-TiS-G) nanocomposite composed of BP, titanium disulfide and graphite has been prepared by a facile and scalable high-energy ball milling method.

LiI/Cu Mixed Conductive Interface via the Mechanical Rolling Approach for Stable Lithium Anodes in the Carbonate Electrolyte.

The nonuniform ion/charge distribution and slow Li-ion diffusion at the Li metal/electrolyte interface lead to uncontrollable dendrites growth and inferior cycling stability. Herein, a simple mechanical rolling method is introduced to construct a mixed conductive protective layer composed of LiI and Cu on the Li metal surface through the replacement reaction between CuI nanoflake arrays and metallic Li. LiI can promote Li transportation across the interface, achieving homogeneous Li flux and suppressing the growth of Li dendrite, while the homogeneously dispersed Cu nanoparticles can offer abundant nucleation sites for Li deposition, resulting in a remarkably homogenized charge distribution.

A Covalent Heterostructure of Metal Phosphide Quantum Dots Anchored in N, P Co-doped Carbon Nanocapsules for Fast and Durable Lithium Storage.

Transition-metal phosphides (TMPs) anodes for lithium ion batteries (LIBs) usually show poor rate capability and rapid capacity degradation owing to their low electronic conductivities, huge volumetric changes, as well as inferior reversibility of the discharge product LiP. Herein, a covalent heterostructure with TMPs quantum dots anchored in N, P co-doped carbon nanocapsules (NPC) has been prepared in which the P element in TMPs is simultaneously doped into the carbon matrix. As a proof of concept, CoP quantum dots covalently anchored in NPC (CoP QDs/NPC) is prepared and evaluated as an anode for LIBs.

Phenoxy Radical-Induced Formation of Dual-Layered Protection Film for High-Rate and Dendrite-Free Lithium-Metal Anodes.

The uncontrollable dendrite growth of Li metal anode leads to poor cycle stability and safety concerns, hindering its utilization in high energy density batteries. Herein, a phenoxy radical Spiro-O8 is proposed as an artificial protection film for Li metal anode owing to its excellent film-forming capability and remarkable ionic conductivity. A spontaneous redox reaction between the Spiro-O8 and Li metal results in the formation of a uniform and highly ionic conductive organic film in the bottom.

An inorganic-rich SEI induced by LiNO additive for a stable lithium metal anode in carbonate electrolyte.

The dissolution of LiNO in carbonate electrolytes is achieved by introducing pyridine as a new carrier solvent owing to its higher Gutmann donor number than NO. The Li metal anode in LiNO-containing carbonate electrolyte demonstrates a much enhanced reversibility due to the preferential reduction of LiNO and the formation of an inorganic-rich SEI.

Facile synthesis of uniform N-doped carbon-coated TiO hollow spheres with enhanced lithium storage performance.

Great efforts, such as nano-structuring and carbon coating, have been devoted to addressing the poor rate performance of TiO2 anodes in lithium ion batteries, which is mainly caused by sluggish Li ion diffusion and poor electrical conductivity of the bulk material. However, the complicated fabrication processes make most of these strategies much low practical significance. Herein, a scalable and facile strategy based on sacrificial template-accelerated hydrolysis and polydopamine coating is proposed to manufacture uniform N-doped carbon-coated TiO2 hollow spheres.

Convenient fabrication of a core-shell Sn@TiO anode for lithium storage from tinplate electroplating sludge.

We here report a unique preparation of a high-performance core-shell Sn@TiO2 anode for lithium ion batteries (LIBs) from tinplate electroplating sludge via a convenient process without deep purification. The Sn@TiO2 shows excellent electrochemical performance due to its core-shell structure. This work provides insight into addressing the electroplating sludge and designing high-performance LIB anodes.

Self-Stabilized and Strongly Adhesive Supramolecular Polymer Protective Layer Enables Ultrahigh-Rate and Large-Capacity Lithium-Metal Anode.

Constructing a solid electrolyte interface (SEI) is a highly effective approach to overcome the poor reversibility of lithium (Li) metal anodes. Herein, an adhesive and self-healable supramolecular copolymer, comprising of pendant poly(ethylene oxide) (PEO) segments and ureido-pyrimidinone (UPy) quadruple-hydrogen-bonding moieties, is developed as a protection layer of Li anode by a simple drop-coating. The protection performance of in-situ-formed LiPEO-UPy SEI layer is significantly enhanced owing to the strong binding and improved stability arising from a spontaneous reaction between UPy groups and Li metal.

General and Scalable Fabrication of Core-Shell Metal Sulfides@C Anchored on 3D N-Doped Foam toward Flexible Sodium Ion Batteries.

Flexible self-standing transitional metal sulfides (TMSs)/carbon nanoarchitectures have attracted widespread research interests for sodium ion batteries (SIBs), thanks to their enormous capability to address intrinsic issues of TMSs for SIBs applications. However, controllable synthesis of hierarchical hybrid structures is always laborious and involves complicated procedures. Herein, a simple yet general and scalable adsorption-annealing strategy is first devised to finely construct core-shell carbon-coated TMSs (TMSs@C, including Co S @C, FeS@C, Ni S @C, MnS@C, and ZnS@C) nanoparticles anchored on 3D N-doped carbon foam (3DNCF) via the coordination and hydrogen-bond adsorption.

Scalable synthesis of FeS nanoparticles encapsulated into N-doped carbon nanosheets as a high-performance sodium-ion battery anode.

Pyrite (FeS) has been considered as one of the most potential anode materials for sodium ion batteries (SIBs) due to its low cost, environmentally friendly features and high theoretical capacity. However, the huge volume changes during a charge/discharge process and poor conductivity of FeS hindered its practical applications. Herein, we propose a facile scalable approach to prepare nanostructured FeS embedded in an N-doped carbon nanosheet composite (FeS/CNS) via a combined template method and a solid state sulfuration method.

Upcycling of Electroplating Sludge into Ultrafine Sn@C Nanorods with Highly Stable Lithium Storage Performance.

Sn-based anode materials have become potential substitutes for commercial graphite anode due to their high specific capacity and good safety. In this paper, ultrafine Sn nanoparticles embedded in nitrogen and phosphorus codoped porous carbon nanorods (Sn@C) are obtained by carbonizing bacteria that adsorb the Sn electroplating sludge extracting solution. The as-prepared Sn@C rod-shaped composite exhibits superior electrochemical Li-storage performances, such as a reversible capacity of approximate 560 mAh/g at 1 A/g and an ultralong cycle life exceeding 1500 cycles, with approximately no capacity decay.

Rational Design of TiO-TiO Heterostructure/Polypyrrole as a Multifunctional Sulfur Host for Advanced Lithium-Sulfur Batteries.

Despite outstanding theoretical energy density (2600 Wh kg) and low cost of lithium-sulfur (Li-S) batteries, their practical application is seriously hindered by inferior cycle performance and low Coulombic efficiency due to the "shuttle effect" of lithium polysulfides (LiPSs). Herein, we proposed a strategy that combines TiO-TiO heterostructure materials (H-TiO , x = 1, 2) and conductive polypyrrole (PPy) to form a multifunctional sulfur host. Initially, the TiO-TiO heterostructure can enhance the redox reaction kinetics of sulfur species and improve the conductivity of sulfur cathode together with the PPy coating layer.

A Scalable Approach for Dendrite-Free Alkali Metal Anodes via Room-Temperature Facile Surface Fluorination.

Alkali metals are attractive anode materials for advanced high-energy-density battery systems because of their high theoretical specific capacities as well as low electrochemical potential. However, severe dendrite growth as well as high chemical reactivity restrict their practical application in energy storage technologies. Herein, we propose a facile scalable solution-based approach to stabilize Li and Na anodes via the facile process of immersing the Li/Na metal in a nonhazardous ionic liquid 1-butyl-2,3-dimethylimidazolium tetrafluoroborate for several minutes at room temperature before battery assembly.

Construction of MoS/C Hierarchical Tubular Heterostructures for High-Performance Sodium Ion Batteries.

Molybdenum disulfide (MoS) has been considered to be a promising anode material for sodium ion batteries (SIBs), because of its high capacity and graphene-like layered structure. However, irreversible conversion reaction during the sodiation/desodiation process is a major problem that must be overcome before its practical applications. In this work, MoS/amorphous carbon (C) microtubes (MTs) composed of heterostructured MoS/C nanosheets have been developed via a simple template method.

PPy-encapsulated SnS Nanosheets Stabilized by Defects on a TiO Support as a Durable Anode Material for Lithium-Ion Batteries.

Nanostructured-alloy-type anodes have received great interest for high-performance lithium-ion batteries (LIBs). However, these anodes experience huge volume fluctuations during repeated lithiation/delithiation and are easily pulverized and subsequently form aggregates. Herein, an efficient method to stabilize alloy-type anodes by creating defects on the surface of the metal oxide support is proposed.

Uniform Li deposition regulated via three-dimensional polyvinyl alcohol nanofiber networks for effective Li metal anodes.

Lithium metal anodes are considered to be the most promising anode material for next-generation advanced energy storage devices due to their high reversible capacity and extremely low anode potential. Nevertheless, the formation of dendritic Li, induced by the repeated breaking and repairing of solid electrolyte interphase layers, always causes poor cycling performance and low coulombic efficiency, as well as serious safety problems, which have hindered the practical application of Li anodes for a long time. Herein, we design an electrode by covering a polyvinyl alcohol layer with a three-dimensional nanofiber network structure through an electrospinning technique.

N/S Co-doped Carbon Derived From Cotton as High Performance Anode Materials for Lithium Ion Batteries.

Highly porous carbon with large surface areas is prepared using cotton as carbon sources which derived from discard cotton balls. Subsequently, the sulfur-nitrogen co-doped carbon was obtained by heat treatment the carbon in presence of thiourea and evaluated as Lithium-ion batteries anode. Benefiting from the S, N co-doping, the obtained S, N co-doped carbon exhibits excellent electrochemical performance.

Exploration of VPO as a new anode material for sodium-ion batteries.

Carbon-coated VPO nanoparticles embedded into a porous carbon matrix were synthesized via a facile sol-gel approach and investigated as a novel polyanion anode material for sodium-ion batteries. The VPO@carbon anode demonstrates excellent rate capability and superior cyclic stability (245.3 mA h g at 1000 mA g after 200 cycles).

LiNiCoMnO with Controllable Morphology and Size for High Performance Lithium-Ion Batteries.

The controllable morphology and size Li-rich Mn-based layered oxide LiNiCoMnO with micro/nano structure is successfully prepared through a simple coprecipitation route followed by subsequent annealing treatment process. By rationally regulating and controlling the volume ratio of ethylene glycol (EG) in hydroalcoholic solution, the morphology and size of the final products can be reasonably designed and tailored from rod-like to olive-like, and further evolved into shuttle-like with the assistance of surfactant. Further, the structures and electrochemical properties of the Li-rich layered oxide with various morphology and size are systematically investigated.

Surface Modification of NaV(PO) by Nitrogen and Sulfur Dual-Doped Carbon Layer with Advanced Sodium Storage Property.

Nitrogen and sulfur dual-doped carbon layer wrapped NaV(PO) nanoparticles (NVP@NSC) have been successfully fabricated by the facile solid-state method. In this hierarchical structure, the NaV(PO) nanoparticles are well dispersed and closely coated by nitrogen and sulfur dual-doped carbon layer, constructing an effective and interconnected conducting network to reduce the internal resistance. Furthermore, the uniform coating layers alleviate the agglomeration of NaV(PO) as well as mitigate the side reaction between electrode and electrolyte.