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To develop a high-energy-density lithium battery, there still are several severe challenges for Li metal anode: low Coulombic efficiency caused by its high chemical reactivity, Li dendrite formation, and "dead" Li accumulation during repeated plating/stripping processes. Especially, lithium dendrite growth imposes inferior cycling stability and serious safety issues. Herein, we propose a facile but effective strategy to suppress lithium dendrite growth through an artificial inorganic-polymer protective layer derived from sulfurized polyacrylonitrile on a polyethylene separator. Benefiting from the lithiated sulfurized polyacrylonitrile and poly(acrylic acid), the flexible and ion-conductive protective layer could regulate Li

Despite high theoretical capacity and earth-abundant resources, the potential industrialization of potassium-sulfur (K-S) batteries is severely plagued by poor electrochemical reaction kinetics and a parasitic shuttle effect. Herein, a facile low-temperature pyrolysis strategy is developed to synthesize N-doped Co nanocluster inlaid porous N-doped carbon derived from ZIF-67 as catalytic cathodes for K-S batteries. To maximize the utilization efficiency, the size of Co nanoparticles can be tuned from 7 nm to homogeneously distributed 3 nm clusters to create more active sites to regulate affinity for S/polysulfides, improving the conversion reaction kinetics between captured polysulfides and K2S3/S, fundamentally suppressing the shuttle effect. Cyclic voltammetry curves, Tafel plots, electrochemical impedance spectroscopy, and density functional theory calculations ascertain that 3 nm Co clusters in S-N-Cos-C cathodes exhibit superior catalytic activity to ensure low charge transfer resistance and energy barriers, enhanced exchange current density, and improved conversion reaction rate. The constructed S-N-Cos-C cathode delivers a superior reversible capacity of 453 mAh g-1 at 50 mA g-1 after 50 cycles, a dramatic rate capacity of 415 mAh g-1 at 400 mA g-1, and a long cycling stability. This work provides an avenue to make full use of high catalytic Co nanoclusters derived from metal-organic frameworks.

Inorganic Na+ conducting solid-state electrolyte (SSE) has received extensive attention in assembling large-scale sodium metal batteries. However, continuous Na dendrites propagation has prevailingly hampered its implementation due to premature cell failure and safety concerns. Herein, a coating layer of AlF3 was decorated between Na anode and NASICON SSE for the first time, which can in situ form a Na+ conducting buffer layer by a conversion reaction with Na during initial cycles. Profiting from the intimate modification of AlF3 interlayer, the Na/SSE interfacial contact is extremely ameliorated. Moreover, owing to the “overpotential triggering” mechanism of the reaction between AlF3 and Na, the locally agminated electron at the anode-electrolyte interface can be released by preferentially driving more Na+ to react with AlF3 instead of forming dendrites at large current density. According to DFT calculations, the critical dendrites length is also enlarged owing to the increased interfacial energy between AlF3-induced interlayer and Na. Therefore, the critical current density of Na/AlF3-NASICON/Na cells has multiplied three-fold to 1.2 ​mA ​cm−2 at 60 ​°C, and the cycling stability of Na metal SSE batteries is also dramatically ameliorated. The rational strategy of modifying AlF3 interlayer is believed to be helpful in resisting dendrites propagation among solid alkalis metal batteries.

The high fluidity and flammability characteristics of the conventional organic liquid electrolyte make it vulnerable for the currently employed commercial lithium batteries to suffer from potential safety risks and premature cell failure. Replacing liquid electrolytes with inorganic solid-state versions coupled with the employment of Li metal anodes is believed to be ideal for next generation energy storage systems with both high security and high energy density. However, even though several promising solid-state electrolytes possess extremely high ionic conductivity, the issues related to a poor electrode/electrolyte interface are a critical constraint. Herein, interface engineering based on current fundamental understanding, challenges, and opportunities of the interface chemistry between inorganic solid-state electrolytes and electrode materials are presented. Firstly, we focus on the interfacial configuration characteristics and mechanisms, pointing out that the unsatisfactory interfacial compatibility and stability, and the dendrite problem are the main drawbacks in achieving high-performance cells, where the interface contact/wettability, constant interfacial reactions, inadequate interfacial Li+ stripping/plating process, and Li dendrite formation/propagation mechanism will be individually reviewed. Then, the recent research status and trends in ameliorating the electrode/electrolyte interface are systematically examined, including the efforts for component optimization and the architectural design of bulk anodes, electrolytes, cathodes, and the interface engineering construction between them. Moreover, several progressive applications and future research directions of interface chemistry will be proposed, aiming to present a comprehensive and enlightening overview for interface engineering that are relevant for the integration of applicable solid-state Li metal batteries.

Phosphosulphide composites began to be used in energy storage field as an emerging category. However, the restricted variety of morphology structure, the large volume expansion and the poor electronic conductivity will lead to the inferior cycling stability. Herein combing with advantages of high electronic conductivity of metallic Sb and high theoretical capacity of phosphorus, non-metallic porous phosphosulfide nanospheres and ultrafine metallic Sb nanoparticles are synergistically anchored on 3D macroporous interconnected carbon foam to form Sb|P-S@C foam anode for high-performance sodium ion batteries (SIBs). The characteristics of porous feature of phosphosulfide nanospheres, high electrical conductivity and ultrafine size of Sb nanoparticles facilitate the alleviation of volume expansion and improvement of charge transfer and diffusion kinetics. 3D macroporous interconnected carbon foam as a framework offers enough active sites for the formation of Sb|P-S particles, not only effectually inhibiting the aggregation of Sb and phosphosulfide nanospheres due to the high surface energy and activity, but also effectively preventing anode material from pulverization and increasing the effective contact area between electrode and electrolyte, serving as 3D channel for electron/ion rapid transfer. Consequently, benefitting from the structural superiorities and synergistic effect, Sb|P-S@C foam anode delivers a specific capacity of 490 mAh g−1 with a remarkable capacity retention after 1000 cycles at 0.1 A g−1. The low-cost strategy for porous Sb|P-S@C foam anode sets up new paths to design long-cycling large-scale energy storage system.

To enhance the structural stability and improve the poor electrochemical reaction kinetics of anodes for sodium ion batteries (SIBs), we develop a novel strategy to couple NiCoP bimetallic phosphide nanoparticles with alkali-induced 3D interconnected crinkled porous Ti3C2 MXenes as anodes for high-performance SIBs. The interconnected 3D Ti3C2 crinkled architectures can establish a 3D conductive network, abundant open pores and large surface area, which provides a 3D conductive highway and unblocked channels for a rapid charge transfer process and for electrolyte storage, and makes fully close contact between the electrode and electrolyte. The unique MXene structure can effectively tolerate volume expansion and prevent aggregation and pulverization of NiCoP nanoparticles during Na+ insertion/extraction processes. The NiCoP bimetallic phosphide possesses richer redox reaction sites, higher electrical conductivity and low charge transfer impedance. The synergistic effect between the components of NiCoP and MXene Ti3C2 with high structural stability and electrochemical activity leads to excellent electrochemical performance, retaining a specific capacity of 261.7 mA h g−1 at a current density of 1 A g−1 for 2000 cycles. The present strategy of an in situ phosphization route and coupling phosphides with crinkled 3D Ti3C2 can be extended to other novel electrodes for high-performance energy storage devices.

The large-scale commercial application of lithium-oxygen batteries (LOBs) is overwhelmed by the sluggish kinetics of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) associated with insoluble and insulated Li2 O2 . Herein, an elaborate design on a highly catalytic LOBs cathode constructed by N-doped carbon nanotubes (CNT) with in situ encapsulated Co2 P and Ru nanoparticles is reported. The homogeneously dispersed Co2 P and Ru catalysts can effectively modulate the formation and decomposition behavior of Li2 O2 during discharge/charge processes, ameliorating the electronically insulating property of Li2 O2 and constructing a homogenous low-impedance Li2 O2 /catalyst interface. Compared with Co/CNT and Ru/CNT electrodes, the Co2 P/Ru/CNT electrode delivers much higher oxygen reduction triggering onset potential and higher ORR and OER peak current and integral areas, showing greatly improved ORR/OER kinetics due to the synergistic effects of Co2 P and Ru. Li-O2 cells based on the Ru/Co2 P/CNT electrode demonstrate improved ORR/OER overpotential of 0.75 V, excellent rate capability of 12 800 mAh g-1 at 1 A g-1 , and superior cycle stability for more than 185 cycles under a restricted capacity of 1000 mAh g-1 at 100 mA g-1 . This work paves an exciting avenue for the design and construction of bifunctional catalytic cathodes by coupling metal phosphides with other active components in LOBs.

Taking advantage of zeolitic imidazolate framework (ZIF-8), ZnS-Sb2S3@C core-double shell polyhedron structure is synthesized through a sulfurization reaction between Zn2+ dissociated from ZIF-8 and S2– from thioacetamide (TAA), and subsequently a metal cation exchange process between Zn2+ and Sb3+, in which carbon layer is introduced from polymeric resorcinol-formaldehyde to prevent the collapse of the polyhedron. The polyhedron composite with a ZnS inner-core and Sb2S3/C double-shell as anode for sodium ion batteries (SIBs) shows us a significantly improved electrochemical performance with stable cycle stability, high Coulombic efficiency and specific capacity. Peculiarly, introducing a carbon shell not only acts as an important protective layer to form a rigid construction and accommodate the volume changes, but also improves the electronic conductivity to optimize the stable cycle performance and the excellent rate property. The architecture composed of ZnS inner core and a complex Sb2S3/C shell not o...

The large-scale commercial application of lithium-oxygen batteries (LOBs) is overwhelmed by the sluggish kinetics of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) associated with insoluble and insulated Li

The size control of active materials among porous carbon architecture remains crucial for the performance of “guest/substrate” nanohybrids anodes among lithium ion batteries. Herein, we prove that graphene oxide (GO) substrate plays an important role on the size control of active materials and put forward a new strategy to controllably adjust oxides particle size on the 3D reduced graphene oxide aerogel (rGOA) structure. Specifically, the active functional groups on GO substrates can be modulated by controlling the gelation degree of GO, which can then realize an in-situ regulation of the active materials growth process due to Ostwald ripening, and the particle size of them are reduced distinctly. The obtained small-size and fine SnO2/Co2SnO4 loaded rGOA architecture (SnO2/Co2SnO4@rGOA-10) shows improved electrochemical performance, where 3D rGOA structure with large numbers of open pores can not only facilitate charge transfer process but also provide unblocked channels for electrolyte transportation. The decrease of nanoparticles size can also shorten ion transfer route within the bulk phase so as to alleviate the volume expansion as well as improve the kinetics of Li+/e− transfer process. The rational strategy of modulating the gelation degree of GO substrates can be extended to synthesize other tunable “guest/substrate” functional nanohybrids.

Taking advantage of nano-sized active materials, doping and self-supporting, Se-doped Bi2S3/3D carbon foam (Bi2S3-xSex/CF) is synthesized through a pyrolysing-hydrothermal-heating three-steps process. The as-synthesized Bi2S3-xSex/CF hybrid exhibits a significant improvement in electrochemical performance, showing a high specific capacity of 441.8 mAh g−1 after 100 cycles with the coulombic efficiency approximating to 100%. The special nanoneedle-like structure of Bi2S3 makes for shortening ion transmission distance, minishing the mechanical stress and thus improving the electrochemical performance. And the introduction of Se can enhance the specific capacity, cycling stability and rate performance by improving of electronic conductivity and forming Se-contained inactive phase during alloying process. Furthermore, the self-supporting electrode is beneficial to simplify preparation process and reduce the loss of volume energy density. The strategy presented in this paper to improve the electrochemical performance of secondary ions battery can be also applied to other novel electrodes materials.

We report on three dimensional Mn-doped Zn2GeO4 hierarchical nanosheet arrays anchored on porous Ni foam as binder-free lithium-ion battery (LIB) anodes with enhanced electrochemical performance. Homogeneous Mn doping effectively induces a great microstructure evolution from nanowire arrays of pure Zn2GeO4 to nanosheet arrays of Mn-doped Zn2GeO4 samples. LIB anodes based on 7% Mn-Zn2GeO4 nanosheet array hierarchical nanostructures anchored on Ni foam display significantly improved electrochemical Li storage performance, showing a superior reversible capacity of 1301 mA h g−1 at a current density of 100 mA g−1 after 100 cycles, almost two times higher than that of 660 mA h g−1 of pure Zn2GeO4 samples. An extraordinarily excellent rate capability with a capacity of 500 mA h g−1 at a current density of 2 A g−1 can be obtained for LIB anodes based on Mn-doped Zn2GeO4 hierarchical nanostructures. The great enhancement of the electrochemical lithium storage performance can be attributed to three-dimensional interconnected conductive channels composed of Ni foam, which not only serves as the current collector but also buffers the volume change of the active material upon cycling. Additionally, Mn doping can greatly improve charge transport kinetics at the interface between the electrode and the electrolyte.

To alleviate large volume change and improve poor electrochemical reaction kinetics of metal phosphide anode for sodium-ion batteries, for the first time, an unique Ni

Taking advantage of zeolitic imidazolate framework (ZIF-8), ZnS-Sb

To alleviate large volume change and improve poor electrochemical reaction kinetics of metal phosphide anode for sodium-ion batteries, for the first time, an unique Ni2 P@carbon/graphene aerogel (GA) 3D interconnected porous architecture is synthesized through a solvothermal reaction and in situ phosphorization process, where core-shell Ni2 P@C nanoparticles are homogenously embedded in GA nanosheets. The synergistic effect between components endows Ni2 P@C/GA electrode with high structural stability and electrochemical activity, leading to excellent electrochemical performance, retaining a specific capacity of 124.5 mA h g-1 at a current density of 1 A g-1 over 2000 cycles. The robust 3D GA matrix with abundant open pores and large surface area can provide unblocked channels for electrolyte storage and Na+ transfer and make fully close contact between the electrode and electrolyte. The carbon layers and 3D GA together build a 3D conductive matrix, which not only tolerates the volume expansion as well as prevents the aggregation and pulverization of Ni2 P nanoparticles during Na+ insertion/extraction processes, but also provides a 3D conductive highway for rapid charge transfer processes. The present strategy for phosphides via in situ phosphization route and coupling phosphides with 3D GA can be extended to other novel electrodes for high-performance energy storage devices.