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As one of the most promising next-generation energy storage devices, the lithium-metal battery has been extensively investigated. However, safety issues and undesired lithium dendrite growth hinder its development. The application of solid-state electrolytes has attracted increasing attention as they can solve safety issues and show great potential to inhibit the growth of lithium dendrites. Polyethylene oxide (PEO)-based electrolytes are very promising due to their enhanced safety and excellent flexibility. However, they suffer from low ionic conductivity at room temperature and cannot effectively inhibit lithium dendrites at high temperatures due to the intrinsic semicrystalline properties and poor mechanical strength. In this work, a novel coral-like Li6.25Al0.25La3Zr2-O12 (C-LALZO) is synthesized to serve as an active ceramic filler in PEO. The PEO with LALZO coral (PLC) exhibits increased ionic conductivity and mechanical strength, which leads to uniform deposition/stripping of lithium metal. The Li symmetric cells with PLC do not cause a short circuit after cycling for 1500 h at 60°C. The assembled LiFePO4/PLC/Li batteries display excellent cycling stability at both 60 and 50°C. This work reveals that the electrochemical properties of the composite electrolyte can be effectively improved by tuning the microstructure of the filler, such as the C-LALZO architecture.

Solid polymer electrolytes (SPEs) are preferable in the pursuit for developing high-energy Li metal batteries due to their inherent flexibility and intimate contact with electrodes. However, contin...

Flexible supercapacitors have drawn tremendous attention resulting from the rapid development of wearable electronic devices. Herein, we develop an effective and facile two-step approach to prepare high content nitrogen, sulfur co-doped porous carbon nanofibers film as electrodes of flexible supercapacitors. Benefiting from the high specific surface area and rich nitrogen/sulfur content, nitrogen and sulfur co-doped porous carbon fibers film (N, S co-doped PCFF) electrodes exhibit a high mass specific capacitance of 307.8 F g−1, and the capacitance retains 98% of initial capacitance after 5000 cycles in a three-electrode system. The as-assembled flexible supercapacitor devices with polyvinyl alcohol/KOH gel electrolyte demonstrate a highest mass specific capacitance of single electrode of 183.9 F g-1 at the scan rate of 2 mV s-1, which is better than that of other heteroatom doping carbon materials. In addition, the energy density reaches as high as 16.35 Wh kg−1 with the power density of 147 W kg−1 and retains as 5.34 Wh kg−1 with higher power density of 2402 W kg−1. Furthermore, the flexible devices show good cycling stability, superior flexibility and stable electrochemical performance.

High ionic conductivity and superior interfacial stability of solid electrolytes at the electrodes are crucial factors for high-performance all-solid-state sodium batteries. Herein, a composite solid electrolyte Na3PS4-polyethylene oxide is synthesized by the solution-phase reaction method with an improved ionic conductivity up to 9.4 × 10−5 S/cm at room temperature. Moreover, polyethylene oxide polymer layer is wrapped homogeneously on the surface of Na3PS4 particles, which could effectively avoid the direct contact between Na3PS4 electrolyte and sodium metal, thus alleviate their side reactions. We demonstrate that all-solid-state battery SnS2/Na with the composite solid electrolyte Na3PS4-polyethylene oxide delivers an enhanced electrochemical performance with 230 mAh/g after 40 cycles.

Rechargeable Li–air (O2) batteries have attracted a great deal of attention because of their high theoretical energy density and been regarded as a promising next-generation energy storage technolo...

Rechargeable lithium–oxygen (Li–O2) batteries (LOBs) with extremely high theoretical energy density have been regarded as a promising next-generation energy storage technology. However, the limited...

Dendritic growth of the metallic lithium anode cannot be fully avoided for prolonged cycling due to the inherent thermodynamic and kinetic tendency, which causes serious safety issues. Here, we strategically control the lithium metal growth direction by designing a three-dimensional porous host with lithiophilic-lithiophobic characterized ligaments. Therefore, lithium metal can only nucleate on the lithiophilic back surface and grow toward the direction away from the separator. Such ‘backside-growth’ can ensure safe battery operation even when lithium dendrites exist. For a proof-of-concept study, highly lithiophilic gold layer is sputtered on backside surface of each copper foam ligament. During lithium plating, lithium nucleates on the lithiophilic backside and keeps growing conformably from the existing nuclei towards the opposite direction to the separator, and eventually forms a lithium-metal layer with highly compacted self-aligned columnar structure. The novel approach controls lithium deposition in two aspects simultaneously: growth direction and morphology. Notably, the featured surface dendrite-free anode exhibits ultra-long-term stable cycling with a high Coulombic efficiency (e.g., 95.0% after 300 cycles, 0.5 mA cm−2, 1 mA h cm−2). This work may not only pave ways for building ultimate safe lithium batteries but also conceptually provides new opportunities for other metal anodes.

Sulfur and nitrogen co-doped graphene aerogel with Janus wettability of superhydrophobic/superhydrophilic was prepared with hydrothermal reduction combined with electrostatic spraying method. The upper surface exhibited an interconnected and porous 3D network with superhydrophobic property (water contact angle > 150°), while the under surface displayed a continuous membrane structure possessing rich wrinkles with superhydrophilicity (water contact angle

Three-dimensional (3D) porous N-doped carbon nanoflake structures decorated with in situ formed Ag nanoparticles (Ag-NCNS) have been synthesized for the first time by a feasible salt-assisted polym...

Low ionic conductivity and poor interfacial compatibility between lithium electrodes and Li7P3S11 sulfide solid electrolytes are the greatest challenges for all-solid state lithium-sulfur batteries. Herein, we introduce a hybrid solid electrolyte with Li7P3S11 being wrapped with polyethylene oxide-LiClO4 (PEO-LiClO4). As served as conductive bridge between Li7P3S11 particles, PEO-LiClO4 would provide Li+ transition paths between Li7P3S11 particles, thus successfully improve its ionic conductivity. Moreover, the polymer layer of PEO-LiClO4 can isolate lithium metal and Li7P3S11 solid electrolyte, suppressing the reaction between lithium electrode and Li7P3S11 electrolyte. Therefore, hybrid solid electrolyte Li7P3S11-PEO-LiClO4 shows excellent interfacial compatibility with lithium foil. Lithium-sulfur battery with the hybrid electrolyte Li7P3S11-PEO-LiClO4 exhibits much improved electrochemical performance with better cycling stability and higher Coulombic efficiency.

Polyoxyethylene (PEO)-based electrolyte is one of the most promising solid-state electrolyte (SSE) candidates for all-solid-state batteries due to its high flexible and salt solubility. Recently, morphological control on active fillers is confirmed as a critical issue affecting the performance of SSE. However, the lack of comprehensive research is hindering the understanding over the growth mechanism of the structured active fillers. Especially, compared with other dimensions, the studies on the growth mechanism of two-dimensional (2D) active fillers are quite limited due to the difficulties in physical methods such as exfoliation. Herein, sheet-like LLZAO (Li6.25La3Zr2Al0.25O12) (SL) is synthesized by bottom-up method to upgrade PEO matrix (SL@PEO). In addition, the growth mechanism of SL is proposed, which provides a new sight for morphology control over inorganic solid electrolytes. The SL structure provides continuous interfaces between the fillers and the polymer matrix, which ensures rapid diffusion of lithium ions. In addition, the SL can provide more nature barriers for electrolyte to suppress the lithium dendrites growth. The lithium symmetric cells adopting SL@PEO present prolonged cycling stability and higher critical current density compared with the control samples. The assembled all-solid-state LiFePO4/SL@PEO/Li batteries exhibit superior cycling stability and rate capability.

Lithium–oxygen batteries (LOBs) have attracted increasing interest because of their superior theoretical specific energy. However, the stability of lithium metal anode is one of the obstacles limiting their practical applications. Here, we introduce an artificial Li3PO4 solid electrolyte interphase (SEI) film to protect the lithium anode in LOB with LiI/LiNO3/DMSO (dimethyl sulfoxide) electrolyte. The Li3PO4-protected Li anode exhibits excellent electrochemical stability during the Li stripping/plating process and leads to a relatively uniform and featureless surface in LOB after cycling. Our research demonstrates that superior electrochemical performance can be achieved in the Li–O2 battery with the synergistic combination of the DMSO-based electrolyte, the LiI redox mediator, and the Li3PO4-protected Li anode. The LOB with a Li3PO4-protected Li anode exhibits a prolonged cycling life span of 152 cycles with a fixed capacity of 1000 mA h g–1 at 2 A g–1. The results in this work provide knowledge for the ...

Rechargeable Li-air (O

Nanostructured spinel LiMn2O4 and super P composite with much enhanced electrochemical performance especially ultrahigh rate capability as the cathode for aqueous hybrid supercapacitors is synthesized by ball milling commercial LiMn2O4 particles together with super P. The as-prepared composite delivers a high capacitance of 306 F g−1 at the current density of 1 A g−1 and superb rate ability of 228.6 F g−1 at 40 A g−1 in 1 M Li2SO4 aqueous electrolyte. The capacitance of the nanostructured composite is 3.5 times higher than that of pristine LiMn2O4 even being charged and discharged 80 times faster. The excellent performances are ascribed to the nanosized LiMn2O4 well dispersed into the conductive carbon matrix. LiMn2O4 and super P composite//active carbon hybrid supercapacitor is assembled and the energy density can reach up to 21.58 Wh kg−1 at 293.16 W kg−1 and 13 Wh kg−1 at 5200 W kg−1. The hybrid device also shows an excellent cycling performance, which retains 85% of the initial capacitance after 4500 cycles. This work provides an effectively facile way to produce high performance LiMn2O4-based cathodes for hybrid suercapacitors in practical applications.

Li7P3S11 (LPS) solid electrolyte (SE) can be used as a coating layer for Si anode as the next generation high energy storage anode material for lithium ion battery (LIB). In this paper, a thin LPS SE was designed to coat on the Si nanoparticles surface to form a core-shell structure by a facile liquid-phase in-situ reaction method. The LPS shell can address the volume expansion of silicon anode successfully during lithiation and delithiation processes. Moreover, it leads to enhancement of the electrochemical performance for Si anode with excellent cycling stability and rate ability. The LPS SE coating is expected to be a promising strategy for other lithium-ion batteries anodes.

Aluminum/graphene (Al/G) composites with enhanced heat-dissipation and mechanical properties were prepared by the powder metallurgy (P/M) technique. Graphene was first uniformly coated on the surface of micro-sized aluminum (Al) powders by an in-situ reduction reaction of GO and Al. Al/G bulk composites with uniform graphene dispersion in Al matrix were fabricated by the simple conventional P/M technique. Enhancements of 15.4% in thermal conductivity, 9.1% in specific heat capacity, 21.1% in hardness, and 25.6% in compressive strength were achieved with only 0.3 wt% graphene addition into pure Al.

The electrode–electrolyte interface stability is a critical factor influencing cycle performance of All-solid-state lithium batteries (ASSLBs). Here, we propose a LiF- and Li3N-enriched artificial solid state electrolyte interphase (SEI) protective layer on metallic lithium (Li). The SEI layer can stabilize metallic Li anode and improve the interface compatibility at the Li anode side in ASSLBs. We also developed a Li1.5Al0.5Ge1.5(PO4)3–poly(ethylene oxide) (LAGP-PEO) concrete structured composite solid electrolyte. The symmetric Li/LAGP-PEO/Li cells with SEI-protected Li anodes have been stably cycled with small polarization at a current density of 0.05 mA cm–2 at 50 °C for nearly 400 h. ASSLB-based on SEI-protected Li anode, LAGP-PEO electrolyte, and LiFePO4 (LFP) cathode exhibits excellent cyclic stability with an initial discharge capacity of 147.2 mA h g–1 and a retention of 96% after 200 cycles.

Red phosphorus (P) has been regarded as an attractive anode material in a sodium-ion battery (SIB) due to its natural abundance and higher theoretical specific capacity. We developed a novel flexible P/carbon nanofibers@reduced graphene oxide (P/CFs@RGO) electrode for sodium-ion batteries through simple vapor-redistribution and electrospinning. In this multi-layer structured P/CFs@RGO electrode, the large volume changes of the red P layer during cycling can be easily buffered and the loss of P from carbon fibers is prevented. In addition, the electrodes have better electron transport. As the result, the as-prepared P/CFs@RGO electrode delivers a high capacity retention of 725.9 mA h g−1 after 55 cycles at 50 mA g−1 and a significant capacity of 406.6 mA h g−1 even at large current densities of 1000 mA g−1 after 180 cycles.

The state-of-art Li-ion batteries have revolutionized the portable electronic industry and first-generation electric vehicles due to their high energy density at ambient temperatures. Owing to catastrophic failures under heat, these power devices are incompatible for applications such as in defence arsenals, subsurface drilling, space exploration and medical appliances, where performance at high-temperatures are as critical. Herein, we report an electrolyte formulation consists of Lithium bis(oxalato)borate (LiBOB) salt dissolved in propylene carbonate that enables lithium batteries to operate at extended temperature regime (>100 °C). The fundamental characterization of electrolyte system such as ionic conductivity, and internal resistance with respect to temperature promising for desired applications. Further, the electrolyte system is used to fabricate lithium batteries and the observed electrochemical results and lithium dendrites suppression capability confirmed its suitability for extended temperature applications without compromising ambient temperature performance.

In an animal body, coronary arteries cover around the whole heart and supply the necessary oxygen and nutrition so that the heart muscle can survive as well as can pump blood in and out very efficiently. Inspired by this, we have designed a novel heart-coronary arteries structured electrode by electrospinning carbon nanofibers to cover active anode graphene/silicon particles. Electrospun high conductive nanofibers serve as veins and arteries to enhance the electron transportation and improve the electrochemical properties of the active “heart” particles. This flexible binder free carbon nanofibers/graphene/silicon electrode consists of millions of heart-coronary arteries cells. Besides, in the graphene/silicon “hearts”, graphene network improves the electrical conductivity of silicon nanopaticles, buffers the volume change of silicon, and prevents them from directly contacting with electrolyte. As expected, this novel composite electrode demonstrates excellent lithium storage performance with a 86.5% capacity retention after 200 cycles, along with a high rate performance with a 543 mAh g−1 capacity at the rate of 1000 mA g−1.

Stable nanofiltration membranes with excellent tolerance to organic solvents and harsh chemical environment are in high demand from petrochemical, pharmaceutical and oil refinery industries. As promising nanofiltration membrane candidates, graphene oxide lamellar membranes suffer from poor flux as well as instability under practical application conditions. Incorporating additional nanopores were believed to be an effective way to improve solvent transportation while enabling efficient molecular sieving. Herein, as a proof of concept, we designed and prepared a hierarchically nanostructured (i.e. with nanopores, micropores, mesopores) graphene oxide/covalent organic framework (GO/COF) hybrid membrane by intercalating imine-based COF nanoparticles. The imine-based COF nanoparticles with inside hollow structure and in-plane nanopores (1.8 nm) as well as abundant edge functional groups become superhydrophilic, providing additional fast transport nanochannels for water and organic solvents molecules in GO matrix. The hierarchically nanostructured GO/COF hybrid membrane shows excellent water (59 L m − 2 h − 1 bar−1) and organic solvents (60 and 51 L m − 2 h − 1 bar−1 of methanol and ethanol, respectively) permeate flux at 1 bar and superior organic dyes rejection rates for Methylene blue (320 g/mol) and Congo red (697 g/mol) in ethanol solvent of 99% and 99.82%, respectively. Additionally, intercalating COF could greatly reduce the GO matrix swelling to enhance membrane stability upon exposure to water as well as strong acidic/base solution, enabling a high filtration performance during long-term (48 h) operation.

Lithium metal is considered as the ultimate anode for next-generation rechargeable batteries due to its high theoretical specific capacity and low electrochemical potential. However, the commercial application of lithium anode is hampered by its dendritic growth during the charging process resulted from the unstable lithium/electrolyte interface. Herein, we demonstrate the formation of a hybrid protective layer consists of LixAl, LiCl and organics on the lithium anode surface. This stable hybrid layer facilitates uniform distribution of Li-ion to eliminate the surface inhomogeneity and thus suppress the dendrite formation. As a result, the modified metallic lithium anode realizes long-term stable cycling with a minimal polarization at 1 mA cm−2 for 1000 h. Furthermore, cells with protected lithium as anode and LiFePO4 as cathode were cycled up to 600 cycles at a 1 C rate with higher capacity retention. This work presents an effective way to regulate a stable lithium anode-electrolyte interface with the formation of a hybrid artificial protective layer to advance lithium metal batteries, which may provide good references for the practical application of Li metal batteries.

High theoretical specific capacity and low electrochemical potential offered by lithium metal make it the definitive anode material for lithium batteries. Yet, unrelenting growth of dendrites forestalls the use of Li metal anode in commercial applications. To overcome this issue, we demonstrate the formation of a multi-phase composite protective layer consists of LixSi alloy, Si-linked organic oligomers and LiCl on the lithium anode surface. Due to its inherent ionic conductivity and chemical stability, the composite film can not only inhibit the formation of lithium dendrites by facilitating uniform Li-ion distribution, but also prevent unfavorable side reactions. The improved electrochemical performance is demonstrated by symmetric cells with the composite layer cycling at 1 mA cm−2 stably for 2200 h. Protected lithium anode coupled with LiFePO4 achieves high rate performance and better capacity retention after 400 cycles at 1C. Furthermore, cells with protected lithium anode and Li4Ti5O12 cathode (high areal loading of 14.9 mg cm−2) shows 91% capacity retention after 400 cycles at 0.5 C. The effective and scalable way to stabilize lithium anode with the multi-phase composite protective layer may serve as good references for development of advanced lithium metal batteries.

Polyethylene-oxide (PEO)-based electrolyte is one of the most promising solid electrolytes due to its outstanding safety and excellent flexibility. However, the most common method to fabricate PEO-based electrolyte is casting, which requires intensive use of toxic organic solvent. Besides, the agglomeration of filler in the composite electrolyte fabricated by casting limits further enhancement of ionic conductivity. In this work, we provide a facile solvent-free cold-pressing method to prepare well-dispersed LAGP @ PEO composite solid-state electrolyte. The ionic conductivity of LAGP @ PEO composite electrolyte can reach about 4.4 × 10−5 S cm−1 at room temperature which is nearly one order of magnitude higher than that of the casting one (3.3 × 10−6 S cm−1). The integrated all-solid-state batteries display excellent cycling stability and good rate performance at 50 °C. Our work provides a facile solvent-free cold-pressing method to fabricate polymer-based composite electrolyte with well-dispersed filler for all-solid-state batteries.

We demonstrate that the double-shell coating of graphene and Li4SiO4 on commercial Si nanoparticles as an effective strategy for improving the anode of lithium ion batteries to overcome the two critical concerns, i.e. rapid capacity decay and inferior coulombic efficiency caused by the large-volume changes. It is proven that the double-shell coating enables the formation of a stable hybrid solid electrolyte interphase, leading to much higher coulombic efficiency and longer cycling stability of the Si anodes. Furthermore, the rate performance of Si is significantly enhanced by the outstanding electrical conductivity of inner graphene layers and the excellent ionic conductivity of Li4SiO4 out-shell. The overall results suggest that this new strategy holds promising perspectives in optimizing electrochemical performances of Si anodes, which should promote their practical applications for next-generation lithium ion batteries with increasingly demanded energy density.