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All-carbon graphdiyne (GDY)-based materials have attracted extensive attention owing to their extraordinary structures and outstanding performance in electrochemical energy storage. Straightforward insights into the interfacial evolution at GDY electrode/electrolyte interface could crucially enrich the fundamental comprehensions and inspire targeted regulations. Herein

Gel polymer electrolytes (GPEs) are one of the promising candidates for high-energy-density quasi-solid-state lithium metal batteries (QSSLMBs), for their high ionic conductivity and excellent interfacial compatibility. The comprehension of dynamic evolution and structure-reactivity correlation at the GPE/Li interface becomes significant. Here, in situ electrochemical atomic force microscopy (EC-AFM) provides insights into the LiNO3-regulated micromechanism of the Li plating/stripping behavior upon cycles in GPE-based LMBs at nanoscale. The additive LiNO3 induces the formation of amorphous nitride SEI film and facilitates the Li+ ion diffusion. It stabilizes a compatible interface and regulates the Li nucleation/growth at steady kinetics. The deposited Li is in the shape of chunks and tightly compact. The Li dissolution shows favorable reversibility, which guarantees the cycling performance of LMBs. In situ AFM monitoring provides a deep understanding into the dynamic evolution of Li deposition/dissolution and the interphasial properties of tunable SEI film, regulating the rational design of electrolyte and interfacial establishment for GPE-based QSSLMBs.

Chemically stable chromenoquinoline (CQ)-based covalent organic frameworks (COFs) were constructed by postsynthetic conversion of imine COFs. The key step of an intramolecular Povarov reaction can transform a preintegrated alkyne group to bridge the benzene rings on both sides of the imine linkage via chemical bonds, affording a ladder-type CQ linkage. This novel approach achieves a high cyclization degree of 80-90%, which endows the CQ-COFs with excellent chemical stability toward strong acid, base, and redox reagents. The synthetic approach can be applied to various monomers with different symmetries and functional core moieties. The absorption and fluorescence intensities of CQ-COFs are sensitive to acid, which allows for dual-mode sensing of strongly acidic environments.

Lithium-oxygen batteries suffer from the degradation of the catalytic cathode during long-term operation, which limits their practical use. Understanding the direct correlations between the surface morphological evolution of catalytic cathodes at nanoscale and their catalytic activity during cycling has proved challenging. Here, using

Among the all-solid-state lithium metal batteries, it is remarkably of importance to realize the superior compatibility and stability of electrode/electrolyte solid-solid interface. A direct viewer of microevolution will induce an in-depth fundamental insight into the reaction mechanisms and interfacial regulations during the cycling operation. Herein, using in situ electrochemical atomic force microscopy combined with optical microscope imaging techniques, we present a dynamic observation of interfacial processes and structural evolution of solid-state electrolyte mediated by lithium salts in a working all-solid-state lithium-sulfur battery (ASSLSB) with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium bis(fluorosulfonyl) imide (LiFSI) and LiTFSI-LiFSI binary-salts. The in-situ monitoring shows that the binary-anion polymer-rich composite electrolytes could well achieve self-regulation in the interfacial compatibility and the side reaction of dissolved polysulfides in enabling ASSLSBs. Moreover, it indicates the anion dependence of ion transportation, interphasial wettability and labile decomposition of electrolytes for ASSLS systems, which determines the dynamic evolution and systematically proposes the corresponding interfacial degradation mechanisms. The in situ visualization provides a direct understanding of ASSLS electrochemical reaction mechanisms and interphasial properties, which will efficiently guide one to explore strategies to develop the optimum all-solid-state systems.

The electrochemical carbon dioxide reduction (ECR) into high-value-added chemicals is a promising approach to alleviate the energy crisis and greenhouse effect. However, the lack of efficient, highly selective, and durable electrocatalysts limits the further application of ECR. Herein, a molecular linking strategy is developed to anchor the monodispersed Bi nanoparticles on a carbon matrix, enabling the durable and efficient CO2 reduction into formate. Systematic characterizations and experimental measurements reveal that tetra-aminophenyl porphyrin (TAPP) can act as an effective molecular linker to secure Bi nanoparticles on porous carbon matrix (Bi NPs/TAPP-PC) via its strong interaction with both the support and nanoparticles, resolving the issues of their peel-off and agglomeration during ECR. Benefiting from the linkage of TAPP molecules, Bi NPs/TAPP-PC exhibits significantly improved ECR performance with a Faradaic efficiency of 92.1% and partial current density of 55.8 mA cm–2 as well as a long-term durability of over 20 h, compared with Bi NPs/PC without TAPP. This strategy using a molecular linker to enhance the activity and durability of the host catalyst provides new insights for developing applicable catalysts for diverse electrocatalytic applications.

Lithium‐ion batteries (LIBs) are booming in multiple fields due to a rapid development in the last decade. However, limited by operational lifespans, a growing number of spent LIBs reaching the end of their lives are consequently faced with serious accumulation and descended to hazardous waste. Without proper disposal, the spent LIBs will inevitably cause negative influence on the ecology and undermine the sustainable manufacture of LIBs. The initial research of recycling strategies mainly focused on the optimization of metallurgical processes. Recently, the sustainability of the recycling process has attracted much more attention and become an important factor. Here, we summarize the recent progress of the spent LIBs recycling from a sustainable perspective, especially discussing the green innovations in recycling strategies for spent LIBs. Through this article, we expect to reveal the challenges and developing tendency of the recycling strategies and provide a guideline for future researches on processing spent LIBs and beyond, like the recycling of the solid‐state lithium metal batteries.

A Kagome structure covalent organic framework (COF) film with three-state near-infrared (NIR) electrochromic properties was designed and synthesized. The morphology and structure characterization revealed that the COFTPDA-PDA film was composed of hexagonal nanosheets with high crystallinity. The COFTPDA-PDA film exhibit three reversible color states at different applied potentials, and high absorption spectra changes in the NIR region, which can be ascribed to the strong intervalence charge transfer (IVCT) interaction of the Class III mixed-valence systems of the conjugated triphenylamine species. The COFTPDA-PDA film showed the sub-second response time (1.3 s for coloring and 0.7 s for bleaching at 1050 nm) and the long retention time in the NIR region. In comparison with the amorphous film with the same monomers, COFTPDA-PDA film show superior NIR electrochromic properties in term of response time and stability, which could be attributed to the highly ordered porous structure and the π-π stacking structure of the COFTPDA-PDA architecture. Furthermore, the COFTPDA-PDA film was successfully applied in mimicking flip-flop logic gate with optical memory functions.

Li+-conductive ceramic oxide electrolytes, such as garnet-structured Li7La3Zr2O12, have been considered as promising candidates for realizing the next-generation solid-state Li-metal batteries with high energy density. Practically, the ceramic pellets sintered at elevated temperatures are often provided with high stiffness yet low fracture toughness, making them too brittle for the manufacture of thin-film electrolytes and strain-involved operation of solid-state batteries. The ceramic powder, though provided with ductility, does not yield satisfactorily high Li+ conductivity due to poor ion conduction at the boundaries of ceramic particles. Here we show, with solid-state nuclear magnetic resonance, that a uniform conjugated polymer nanocoating formed on the surface of ceramic oxide particles builds pathways for Li+ conduction between adjacent particles in the unsintered ceramics. A tape-casted thin-film electrolyte (thickness

Zinc–air batteries (ZABs) are among the most promising electrochemical energy storage devices which feature high energy density, decent rechargeability, low cost, and eco-friendliness. However, the...

The solid electrolyte interphase (SEI) has caught considerable attention as a pivotal factor affecting lithium (Li) metal battery performances. However, the understanding of the interfacial evolution and properties of the on-site formed SEI shells on Li deposits during cycling is still at a preliminary stage. Here, we provide a straightforward visualized evidence of SEI shells’ evolution during Li deposition/stripping to reveal anode degradation via in-situ atomic force microscopy (AFM). Nucleation and growth of quasi-spherical Li particles are observed on a Cu substrate, followed by Li stripping and collapse of SEI shells. In the subsequent cycling, new Li deposits tend to nucleate at pristine sites with fresh SEI shells forming on Li. The previously collapsed SEI shells accumulate to increase interface impedance, eventually leading to capacity degradation. Revealing the electrochemical processes and interfacial degradation at the nanoscale will enrich fundamental comprehension and further guide improvement strategies of Li metal anodes.

The diverse topological structure, designable building blocks, ordered pores and crystalline architecture of covalent organic frameworks (COFs) make them attractive in many application fields. Howe...

Stable solid electrolyte interphase (SEI) has been well established to be critical for the reversible operation of Li (ion) batteries, yet our understanding of its mechanical properties currently remains incomplete. Here, we used an electrochemical quartz crystal microbalance combined with dissipation monitoring (EQCM-D) to investigate SEI formation. By quantitatively estimating in-situ, the change in mass, shear modulus, and viscosity of the SEI, we show that the SEI formation in propylene carbonate (PC)- and ethylene carbonate/diethyl carbonate (EC/DEC)-based electrolytes involves the growth of a rigid layer followed by a viscoelastic layer, whereas a distinct “one-layer” rigid model is applicable to the SEI formulated in tetraethylene glycol dimethyl ether (TEGDME)-based electrolyte. With the continuous formation of the SEI, its shear modulus decreases accompanied by an increase in viscosity. In TEGDME, the lightest/thinnest SEI (mass lower than in PC by a factor of nine) yet having the greatest stiffness (more than five times that in PC) is obtained. We attribute this behavior to differences in the chemical composition of the SEIs, which have been revealed by tracking the mass-change-per-mole-of-electron-transferred using EQCM-D and further confirmed by X-ray photoelectron spectroscopy.

Lithium-sulfur (Li-S) batteries have become prospective candidates for next-generation energy storage owing to the high energy density and low cost. However, the sluggish kinetics of the electrochemical reaction and shuttle effect result in a rapid capacity decay. Herein, a titanium nitride nanocrystal/N-doped graphene (TiN@NG) composite is developed to host elemental sulfur. The TiN nanoparticles decorated on graphene sheets attract Li polysulfides (LiPSx) and catalyze the electrochemical reduction and oxidation of LiPSx in the discharge and charge processes, respectively. These two effects effectively restrain the dissolution of the LiPSx and accelerate the electrochemical reactions, thereby, alleviating the shuttle effect. As a result, the cathode composed of TiN@NG/S delivers a remarkable reversible capacity (1390 mA h g−1 at 0.1 C) and excellent cycling performance (730 mA h g−1 after 300 cycles). We believe that this work can bring some inspiration for designing high-performance Li-S batteries.