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The CO2 treatment on argyrodite sulfide-based solid electrolyte Li6PS5Cl (LPSC) can effectively improve the interfacial stability between the Li and LPSC.

Advancing new ideas of rechargeable batteries represents an important path to meeting the ever increasing energy storage needs. Recently we showed rechargeable sodium/chlorine (Na/Cl$_2$) (or lithium/chlorine Li/Cl$_2$) batteries that used a Na (or Li) metal negative electrode, a microporous amorphous carbon nanosphere (aCNS) positive electrode and an electrolyte containing dissolved AlCl$_3$ and fluoride additives in thionyl chloride (SOCl$_2$). The main battery redox reaction involved conversion between NaCl and Cl$_2$ trapped in the carbon positive electrode, delivering a cyclable capacity of up to 1200 mAh g$^{-1}$ (based on positive electrode mass) at a ~ 3.5 V discharge voltage. Here, we discovered by X-ray photoelectron spectroscopy (XPS) that upon charging a Na/Cl$_2$ battery, chlorination of carbon in the positive electrode occurred to form C-Cl accompanied by molecular Cl$_2$ infiltrating the porous aCNS, consistent with Cl$_2$ probed by mass spectrometry. Synchrotron X-ray diffraction observed the development of graphitic ordering in the initially amorphous aCNS under battery charging when the carbon matrix was oxidized/chlorinated and infiltrated with Cl$_2$. The C-Cl, Cl$_2$ species and graphitic ordering were reversible upon discharge, accompanied by NaCl formation. The results revealed redox conversion between NaCl and Cl$_2$, reversible graphitic ordering/amorphourization of carbon through battery charge/discharge, and for the first time probed trapped Cl$_2$ in porous carbon by XPS., Comment: 30 pages, 9 figures

Background Anode-free lithium metal batteries (AFLMBs) are promising power sources. However, Li dendrite and dead Li formation hindered it from practical applications. These challenges mainly result from inhomogeneous Li plating and fragile SEI due to the rough bare copper (bare Cu) surface and commonly used carbonate electrolytes. Methods Herein, we designed a two-step modification on the copper surface with synthesized Ag nanoparticles wrapped with polydopamine (Ag@P) and an artificial protection film (APF) to introduce an interface functional double layers. The first layer serves as Li-seeds for uniform Li nucleation and deposition. The latter (PVDF-HFP/LiTFSI) encapsulates the deposited Li to promote the formation of an anion-derived compact SEI film and minimize the inevitable electrolyte decomposition with Li. Significant findings It is found that the double-layer coating on copper enables homogenous and Li dendrite-free morphology. The anode-free cell with double layer-coated copper and NMC cathode maintains a superior coulombic efficiency (CE) of 98.15% and over 70 cycles at 40% capacity retention (CR) compared to the CE of 96.18% after 25 cycles at 40% CR on the bare Cu under 0.2 mA cm−2. These prominent achievements stem from the synergetic role of the lithiophilic Ag nanoparticles and the generation of an anion-derived robust LiF-rich SEI film. This study offers an alternative approach for current collector surface modification for the feasibility of AFLMBs.

Lithium-ion batteries (LIBs) are widely used in applications ranging from electric vehicles to wearable devices. Before the invention of secondary LIBs, the primary lithium-thionyl chloride (Li-SOCl2) battery was developed in the 1970s using SOCl2 as the catholyte, lithium metal as the anode and amorphous carbon as the cathode1–7. This battery discharges by lithium oxidation and catholyte reduction to sulfur, sulfur dioxide and lithium chloride, is well known for its high energy density and is widely used in real-world applications; however, it has not been made rechargeable since its invention8–13. Here we show that with a highly microporous carbon positive electrode, a starting electrolyte composed of aluminium chloride in SOCl2 with fluoride-based additives, and either sodium or lithium as the negative electrode, we can produce a rechargeable Na/Cl2 or Li/Cl2 battery operating via redox between mainly Cl2/Cl− in the micropores of carbon and Na/Na+ or Li/Li+ redox on the sodium or lithium metal. The reversible Cl2/NaCl or Cl2/LiCl redox in the microporous carbon affords rechargeability at the positive electrode side and the thin alkali-fluoride-doped alkali-chloride solid electrolyte interface stabilizes the negative electrode, both are critical to secondary alkali-metal/Cl2 batteries. Rechargeable Na/Cl2 and Li/Cl2 batteries are produced with a microporous carbon positive electrode, aluminium chloride in thionyl chloride as the electrolyte, and either sodium or lithium as the negative electrode.

Anode-free lithium-metal batteries employ in situ lithium-plated current collectors as negative electrodes to afford optimal mass and volumetric energy densities. The main challenges to such batteries include their poor cycling stability and the safety issues of the flammable organic electrolytes. Here, a high-voltage 4.7 V anode-free lithium-metal battery is reported, which uses a Cu foil coated with a layer (≈950 nm) of silicon-polyacrylonitrile (Si-PAN, 25.5 µg cm

A zinc metal anode for zinc-ion batteries is a promising alternative to solve safety and cost issues in lithium-ion batteries. The Zn metal is characterized by its high theoretical capacity (820 mAh g

Lithium metal anode material suffers from the formation of a dendritic structure and manufacturing difficulties in Li metal batteries. Although anode-free lithium metal batteries (AFLMBs) have rece...

Organic electrolytes react aggressively with lithium (Li) active materials, especially at 60 °C, exhibiting uncontrolled dendrite growth. Herein, β-poly(vinylidene difluoride) (PVDF) polymer confor...

The low ionic conductivity, thermal stability and incompatibility of pellet-like solid-state electrolytes lead to low cycling performance in anode-free lithium metal batteries. Herein, we report an...

Li7La3Zr2O12 (LLZO) garnet is one kind of solid electrolyte drawing extensive attention due to its good ionic conductivity, safety, and stability toward lithium metal anodes. However, the stability...

Li1.5Al0.5Ge1.5(PO4)3 (LAGP) is a promising solid electrolyte for use in next-generation lithium batteries. Nevertheless, its lower bulk and grain-boundary ionic conductivities are major restrictions preventing its practical utilization. Mg was introduced into LAGP to form Li1.6Al0.4Mg0.1Ge1.5(PO4)3 (LAMGP) based on computational analysis. The doping of LAGP with Mg results in advantages such as increasing the Li+ concentration and expanding the material dimensions due to the larger ionic radius of Mg, leading to enhanced ionic conductivity. Mg had a two-birds-with-one-stone effect in the LAMGP electrolyte, not only generating super high bulk ionic conductivity of 7.435 mS cm−1, compared to 2.896 mS cm−1 in LAGP, but also generating low grain-boundary resistance due to improved densification. The lowering of the grain-boundary resistance and the increased densification are related to choosing the right precursor for the dopant. Using LAMGP as a hybrid solid electrolyte, a solid battery delivered great electrochemical performance in comparison to when LAGP was used. Interfacial analysis was also conducted, which revealed that the formation of an interface prevented the reduction of components in LAMGP by Li metal, therefore ensuring the long-term durability of LAMGP in liquid electrolyte. These results suggest that LAMGP is an auspicious solid electrolyte for achieving practical solid-state lithium batteries.

ConspectusLithium (Li) metal is the ultimate negative electrode due to its high theoretical specific capacity and low negative electrochemical potential. However, the handling of lithium metal imposes safety concerns in transportation and production due to its reactive nature. Recently, anode-free lithium metal batteries (AFLMBs) have drawn much attention because of several of their advantages, including higher energy density, lower cost, and fewer safety concerns during cell production compared to LMBs. Pushing the reversible Coulombic efficiency (CE) of AFLMBs up to 99.98% is key to achieving their 80% capacity retention over more than 1000 cycles. However, interfacial irreversible phenomena such as electrolyte decomposition reactions on both electrodes, dead Li formation, and Li dendrite formation result in poor capacity retention and short circuits in LMBs and AFLMBs. Therefore, it is of great importance and scientific interest to explore those interfacial irreversible phenomena to improve the cell's cycle life. Although significant contributions toward mitigating electrolyte decomposition, dead lithium, and dendritic lithium formation have been reported at the lithium anode, real irreversible phenomena are usually hidden or difficult to discover due to excess lithium employed in LMBs and simultaneous events taking place in both electrodes or at the interfaces.An integrated protocol is suggested to include Li||Cu, cathode||Li, and cathode||Cu configurations to provide overall quantification and determination of various sources of irreversible Coulombic efficiency (irr-CE) in AFLMBs and LMBs. Combining Li||Cu, cathode||Li, and cathode||Cu configurations is essential for separating the root sources of the capacity loss and irr-CE in LMBs and AFLMBs. Remarkably, integrating an anode-free cell with various analytical techniques can serve as a powerful protocol to decouple and quantify those interfacial irreversible phenomena according to our recent reports.In this Account, we focus on the protocol based on an anode-free cell combined with various analytical methods to investigate interfacial irreversible phenomena. Complementary advanced tools such as transmission X-ray microscopy (visualizing Li plating/stripping mechanism), nuclear magnetic resonance spectroscopy (quantifying dead lithium), and gas chromatography-mass spectroscopy (decoupling interfacial reactions) were employed to extract the intrinsic reasons and sources of individual irreversible reactions in LMBs and AFLMBs. Quantitative evaluation of nucleation and growth of Li metal deposition are addressed, along with solid electrolyte interphase (SEI) fracture, visualization of lithium dendrite growth, decoupling of oxidative and reductive electrolyte decomposition mechanisms, and irreversible efficiency (i.e., dead Li and SEI formation) to reveal the intrinsic causes of individual irr-CE in AFLMBs. Meanwhile, an anode-free protocol can also be utilized as a powerful and multifunctional tool to develop electrolyte formulations or artificial layers for LMBs and AFLMBs. Therefore, we also suggest that the anode-free configurations with significant irreversible phenomena can effectively screen and develop new electrolytes. Finally, the concepts of the protocol with an anode-free cell combined with various advanced analytical tools can be extended to provide an in-depth understanding of other metal batteries and solid-state anode-free metal batteries.

Two types of racemic rodlike Schiff base mesogens with –CN– (type I) and –NC– (type III) linkages were prepared. These mesogens possessed either difluoro substitutions at the inner-core position of the phenyl ring or hydroxy group to form intramolecular hydrogen bonding with an ester or/and imine linkage. When the appropriate concentration of chiral additive is doped into them, the incorporation of two fluoro substituents is more useful for blue phase (BP) stabilization than that of a hydroxy group near the ester linkage in Schiff base mesogens. BPI and BPII can be identified by reflectance spectra and polarized optical microscope images. BPII emerges easily on cooling when the appropriate chiral dopant ISO(6OBA)2 or chiral dopant S811 is doped into the Schiff base mesogen having only a hydroxy group near the ester linkage. Interestingly, BPI can be observed when 10–15 wt% ISO(6OBA)2 was doped into the difluoro substituted Schiff base mesogen III during a heating process. The experimental and molecular modeling results indicate that most of the difluorinated Schiff base mesogens with larger dipole moments exhibit wider BP ranges than their corresponding non-fluorinated homologues under the same chirality condition. In addition, wide BPs can be induced for racemic rodlike Schiff base mesogens I in the chiral system and this is easier than that for racemic rodlike Schiff base mesogens III. In Schiff base mesogens I, the dipole moment is dominant for BP stabilization. However, the fluorine substituent effect is the main factor in Schiff base mesogens III.

Lithium-ion batteries (LIBs) are widely used in applications ranging from electric vehicles to wearable devices. Before the invention of secondary LIBs, the primary lithium-thionyl chloride (Li-SOCl

The decent ductileness, high ionic conductivity, low cost, and versatility over synthesis methods make Li-argyrodite a promising for all-solid-state lithium batteries. However, its serious interfacial incompatibility with Li anode, dendrite growth, and intrinsic air instability impedes its practicability. Herein, we report a CuCl dual doped Li-argyrodite sulfide superb-conductor (Li6+3xP1−xCuxS5−xCl1+x) prepared to overcome these issues via ball-mill free synthesis approach. The maximum Li+ conductivity of 4.34 mS cm−1 at room temperature with ultrawide voltage stability up to 8 V vs. Li/Li+ was achieved in Li6.3P0.9Cu0.1S4.9Cl1.1 (LPSC-1) via a both composite and planar electrode system and can suppress dendrite formation at a current density of 3 mA cm−2 at 50 оC. The symmetrical cell cycled at 0.1 and 1 mA cm−2 also demonstrates remarkable reversibility with negligible overpotential alteration for more than 2400 h and 400 h. An ex-situ XPS and AC impedance analysis proved enhanced interfacial compatibility at Li | SE and achieved a critical current density of 3 mA cm−2. More interestingly, incorporating soft acid Cu in LPSC-1 boosts the air stability and suppresses H2S generation by two-folds. The XRD for the LPSC-1 before and after air exposure proves the decrease in the oxophilicity of the sulfide solid electrolyte.

The development of high-performance polymer electrolytes will be a crucial research target for flexible solid-state supercapacitors (FSSCs). In this study, a flexible gel polymer electrolyte (GPE) was fabricated to enhance flexible solid-state supercapacitor (FSSC) performance and electrochemical stability. 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfony)imide was used as ionic liquid (IL), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) as a host polymer with Li1.5Al0.33Sc0.17Ge1.5(PO4)3 (LASGP) serving as ceramic filler to fabricate the GPE films. Scanning electron microscope (SEM) image confirmed that a homogeneous uniform phase with a smooth surface was formed as the ionic liquid was added into the host polymer solution. X-ray diffraction (XRD) patterns show that the PVDF-HFP blend has a semi-crystalline structure while its amorphous nature extended with the increasing amount of IL and LASGP ceramic fillers. The GPE film was used as the electrolyte and separator, due to its high ionic conductivity ( 7.8 × 10 - 2 S cm−1) and excellent thermal stability up to 346 ℃. The FSSC cell with LASGP ceramic filler exhibits a high specific capacitance (115.45 F g−1) with a specific energy density of 27.10 Wh kg−1 at 1 mA. These results indicate that a GPE film with an activated carbon electrode could be a candidate for FSSC applications.

Take composite wallboard of residential parts as object of study, use investigation and theoretical calculation to check unfavorable conditions of Mold-unloading-lifting and lifting-transportation in industrial production. mold-unloading coefficient and dynamic coefficient value are researched according to summarize domestic and foreign standard, and give out suggested dynamic coefficient values of construction checking of lifting-transportation for composite wallboard. It can provide reference of production and development of residential parts.

Lithium metal is considered as an ideal anode material for lithium-ion batteries, because of its highest theoretical specific capacity, energy density, low reduction potential, and lightweight. However, its practical application is being hindered by factors such as the presence of uncontrolled interfacial reactions with liquid electrolytes, unstable solid electrolyte interphase (SEI), dendrite formation due to inhomogeneous lithium-deposition and poor cycle life. Herein, Lithium ion conducting composite film comprising of cubic garnet (Li7La2.75Ca0.25Zr1.75Nb0.25O12) (LLCZN), polyvinylidene fluoride (PVDF) and lithium perchlorate (LiClO4) salt is prepared by electrospinning. The composite film induces inorganic-rich solid electrolyte interphase which is mechanically stable to suppress the formation of lithium dendrites. The Li‖Cu@LLCZN/PVDF(84:16)LiClO4 cell exhibits negligible polarization compared to a bare copper one (Li‖Cu) performed in 1 M LiPF6 ethylene carbonate (EC) diethyl carbonate (DEC) (1:1 v/v ratio) electrolyte at a current density of 0.2 mA cm−2. Moreover, the anode free full cell configuration (Cu@LLCZN/PVDF‖NMC) demonstrates improved capacity retention of 58.66% and average coulombic efficiency of 97.6% after 30th cycles compared to Cu‖NMC cell. The as-synthesized composite film induces inorganic rich (LiF and LiCl) SEI and gives required mechanical strength to suppress the lithium dendrite formation. These features endow the Cu anode with stable interface chemistry which is essential to the realization of anode-free lithium metal batteries.