The development of lithium (Li) metal anodes Li metal batteries faces huge challenges such as uncontrolled Li dendrite growth and large volume change during Li plating/stripping, resulting in severe ...capacity decay and high safety hazards. A 3D porous copper (Cu) current collector as a host for Li deposition can effectively settle these problems. However, constructing a uniform and compact 3D porous Cu structure is still an enormous challenge. Herein, an electrochemical etching method for Cu–Zinc (Zn) alloy is reported to precisely engrave a 3D Cu structure with uniform, smooth, and compact porous network. Such a continuous structure endows 3D Cu excellent mechanical properties and high electrical conductivity. The uniform and smooth pores with a large internal surface area ensures well dispersed current density for homogeneous Li metal deposition and accommodation. A smooth and stable solid electrolyte interphase is formed and meanwhile Li dendrites and dead Li are effectively suppressed. The Li metal anode conceived 3D Cu current collector can stably cycle for 400 h under an Li plating/stripping capacity of 1 mA h cm−2 and a current density of 1 mA cm−2. The Li@3D Cu||LiFePO4 full cells present excellent cycling and rate performances. The electrochemical dealloying is a robust method to construct 3D Cu current collectors for dendrite‐free Li metal anodes.
The electrochemical etching method is presented to prepare 3D Cu with a uniform and compact porous network. As current collector of Li metal anode, the 3D Cu with large internal surface area and enhanced mechanical properties can effectively accommodate Li metal and suppress Li dendrite growth to achieve a high performance in a Li–metal battery.
Li metal has been widely regarded as a promising anode for next‐generation batteries due to its high theoretical capacity and low electrochemical potential. The unstable solid‐electrolyte interphase ...(SEI) and uncontrollable dendrite growth, however, incur severe safety hazards and hamper the practical application of Li metal anodes. Herein, an advanced artificial SEI layer constructed by LiNBHn chains, which are crosslinked and self‐reinforced by their intermolecular LiN ionic bonds, is designed to comprehensively stabilize Li metal anodes on a molecular level. Benefiting from its polymer‐like structure, the LiNBHn layer is flexible and effectively tolerates the volume change of Li metal anodes. In addition, this layer with high polarity in its structure, helps to regulate the homogeneous distribution of the Li+ flux on Li electrodes via the further formation of LiN bonds. The designed LiNBHn layer is electrically nonconductive but highly ionically conductive, thus facilitating Li+ diffusion and confining Li deposition beneath the layer. Therefore, under the protection of the LiNBHn layer, the Li metal anodes exhibit stable cycling at a 3 mA cm−2 for more than 700 h, and the full cells with high lithium iron phosphate and sulfur cathodes mass loading also present excellent cycling stability.
An advanced LiNBHn layer is designed from a new bottom‐up perspective to molecularly serve as an artificial solid‐state interphase for Li metal anodes. This layer features both organic and inorganic characteristics with high ionic conductivity, high flexibility, comparable mechanical strength, and high polarity, thus comprehensively suppressing Li dendrite growth.
A 3D porous Cu current collector is fabricated through chemical dealloying from a commerial Cu–Zn alloy tape. The interlinked porous framework naturally integrated can accommodate Li deposition, ...suppressing dendrite growth and alleviating the huge volume change during cycling. The Li metal anode combined with such a porous Cu collector demonstrates excellent performance and commerial potentials in Li‐based secondary batteries.
Multi‐heteroatoms co‐doped carbon coating can significantly enhance the electronic conductivity and mass transfer rate of the electrode materials due to the synergistic effect. In this study N, S ...co‐doped carbon coating is introduced on the surface of niobium oxides (GNO@NSC) by using a convenient thiourea evaporation method. Theory calculations and experimental results confirm the synergistic effect of N, S co‐doping in GNO@NSC composite. N, S co‐doping not only enlarges the layer distance of the carbon materials but also leads to more activation sites for lithium storage; meanwhile, the introduction of the co‐doping carbon layer on GNO significantly enhances the bonding interaction with GNO, leading to excellent structural stability and conductivity of the composite. As a result, the GNO@NSC composite possesses excellent structural reversibility, a large specific capacity, and high‐rate performance. GNO@NSC nanowires deliver a highly reversible capacity of 288 mAh g–1 and display excellent cycling stability, and its capacity retention is 78.9% after 6000 cycles at a high current density of 1 A g–1. This study reveals the functional mechanism of N, S co‐doped carbon coating and the origin of performance improvement of niobium oxides, which can be used for reference to design and develop relevant materials.
A nitrogen and sulfur co‐doped carbon coating can arouse synergistic effects to boost the electrochemical properties of a composite. Due to the strong bonding interaction, activation sites for lithium storage, large interlayer spacing, and stable structure in the nitrogen and sulfur co‐doped carbon layer, GNO@NSC displays superior rate performance, long cycling performance, and larger lithium‐ion diffusion coefficient.
All‐solid‐state lithium metal battery is the most promising next‐generation energy storage device. However, the low ionic conductivity of solid electrolytes and high interfacial impedance with ...electrode are the main factors to limit the development of all‐solid‐state batteries. In this work, a low resistance–integrated all‐solid‐state battery is designed with excellent electrochemical performance that applies the polyethylene oxide (PEO) with lithium bis(trifluoromethylsulphonyl)imide as both binder of cathode and matrix of composite electrolyte embedded with Li7La3Zr2O12 (LLZO) nanowires (PLLN). The PEO in cathode and PLLN are fused at high temperature to form an integrated all‐solid‐state battery structure, which effectively strengthens the interface compatibility and stability between cathode and PLLN to guarantee high efficient ion transportation during long cycling. The LLZO nanowires uniformly distributed in PLLN can increase the ionic conductivity and mechanical strength of composite electrolyte efficiently, which induces the uniform deposition of lithium metal, thereby suppressing the lithium dendrite growth. The Li symmetric cells using PLLN can stably cycle for 1000 h without short circuit at 60 °C. The integrated LiFePO4/PLLN/Li batteries show excellent cycling stability at both 60 and 45 °C. The study proposed a novel and robust battery structure with outstanding electrochemical properties.
A low resistance–integrated all‐solid‐state Li metal battery with excellent electrochemical performance is designed. The structure not only guarantees high ionic conductivity and good mechanical properties to suppress lithium dendrite growth by using polyethylene oxide (PEO)/lithium bis(trifluoromethylsulphonyl)imide embedded with Li7La3Zr2O12 nanowire composite electrolyte, but also decreases the interfacial impedance by applying PEO in both electrolyte and cathode that can fuse during operation.
The combination of photoredox and enzymatic catalysis for the direct asymmetric one‐pot synthesis of 2,2‐disubstituted indol‐3‐ones from 2‐arylindoles through concurrent oxidization and alkylation ...reactions is described. 2‐Arylindoles can be photocatalytically oxidized to 2‐arylindol‐3‐one with subsequent enantioselective alkylation with ketones catalyzed by wheat germ lipase (WGL). The chiral quaternary carbon center at C2 of the indoles was directly constructed. This mode of concurrent photobiocatalysis provides a mild and powerful strategy for one‐pot enantioselective synthesis of complex compounds. The experiments proved that other lipases containing structurally analogous catalytic triad in the active site also can catalyze the reaction in the same way. This reaction is the first example of combining the non‐natural catalytic activity of hydrolases with visible‐light catalysis for enantioselective organic synthesis and it does not require any cofactors.
Look, no cofactors! The combination of photoredox and enzymatic catalysis enables the direct asymmetric one‐pot synthesis of C2‐quaternary indolin‐3‐ones from 2‐arylindoles. This reaction is the first example of combining the non‐natural catalytic activity of hydrolases with visible‐light catalysis for enantioselective organic synthesis, and it does not require any cofactors.
Lithium (Li) metal is promising for high energy density batteries due to its low electrochemical potential (−3.04 V) and high specific capacity (3860 mAh g−1). However, the safety issues impede the ...commercialization of Li anode batteries. In this work, research of hierarchical structure designs for Li anodes to suppress Li dendrite growth and alleviate volume expansion from the interior (by the 3D current collector and host matrix) to the exterior (by the artificial solid electrolyte interphase (SEI), protective layer, separator, and solid state electrolyte) is concluded. The basic principles for achieving Li dendrite and volume expansion free Li anode are summarized. Following these principles, 3D porous current collector and host matrix are designed to suppress the Li dendrite growth from the interior. Second, artificial SEI, the protective layer, and separator as well as solid‐state electrolyte are constructed to regulate the distribution of current and control the Li nucleation and deposition homogeneously for suppressing the Li dendrite growth from exterior of Li anode. Ultimately, this work puts forward that it is significant to combine the Li dendrite suppression strategies from the interior to exterior by 3D hierarchical structure designs and Li metal modification to achieve excellent cycling and safety performance of Li metal batteries.
The strategy of suppressing Li dendrite growth and accommodating volume expansion is put forward from a new perspective of hierarchical structure designs of the Li anode from the interior (3D porous current collector and host matrix) to exterior (artificial solid electrolyte interphase (SEI), protective layer, separator, and solid‐state electrolyte). The Li dendrite growth mechanisms and suppression strategies are also concluded.
Due to high ionic conductivity and low cost, Li1.4Al0.4Ti1.6(PO4)3 (LATP) has emerged as a promising solid‐state electrolyte for next‐generation lithium (Li) metal solid‐state batterie with high ...safety performance and energy density. However, the extremely high impedance and surface instability of LATP with Li metal retard its practical application. Herein, a novel method is proposed to construct an ultrathin ZnO layer that is tightly coated on the LATP pellets, surface (ZnO@LATP) via magnetron sputtering, which in situ reacts with Li to form a low electronic conductivity and multifunctional solid electrolyte interphase (SEI). The formed SEI can not only effectively lower the interfacial resistance, but also overcome the side reactions of LATP with the Li metal anode and suppress the Li dendrite growth. Specifically, the interface resistance decreases from 80 554 to 353 Ω and the overpotential reduces from 1 V to 20 mV. As a result, the Li/ZnO@LATP@ZnO/Li symmetric batteries can stably cycle for more than 2000 h without short circuit at 0.05 mA cm−2 and Li/ZnO@LATP/LiFePO4 batteries show excellent cycle stability for 200 cycles at 0.1 C. This work highlights the significance of multifunctional interphase between LATP and Li metal for improvement of interfacial impedance and instability.
A novel method is proposed to construct a stable multifunctional interphase between Li1.4Al0.4Ti1.6(PO4)3 and Li metal via magnetron sputtering. The interphase formed by the in situ reaction of ZnO with Li metal with low ionic conductivity not only reduces the interfacial impedance, but also suppresses the continuous side reactions of Li1.4Al0.4Ti1.6(PO4)3 with Li metal and the Li dendrite growths.
The lithium–sulfur (Li–S) battery is a next generation high energy density battery, but its practical application is hindered by the poor cycling stability derived from the severe shuttling of ...lithium polysulfides (LiPSs). Catalysis is a promising way to solve this problem, but the rational design of relevant catalysts is still hard to achieve. This paper reports the WS2–WO3 heterostructures prepared by in situ sulfurization of WO3, and by controlling the sulfurization degree, the structure is controlled, which balances the trapping ability (by WO3) and catalytic activity (by WS2) toward LiPSs. As a result, the WS2–WO3 heterostructures effectively accelerate LiPS conversion and improve sulfur utilization. The Li–S battery with 5 wt% WS2–WO3 heterostructures as additives in the cathode shows an excellent rate performance and good cycling stability, revealing a 0.06% capacity decay each cycle over 500 cycles at 0.5 C. By building an interlayer with such heterostructure‐added graphenes, the battery with a high sulfur loading of 5 mg cm−2 still shows a high capacity retention of 86.1% after 300 cycles at 0.5 C. This work provides a rational way to prepare the metal oxide–sulfide heterostructures with an optimized structure to enhance the performance of Li–S batteries.
A WS2–WO3 heterostructure catalyst is prepared through a controllable in situ sulfurization of WO3. The well‐balanced composition of this heterostructure optimizes the trapping ability for lithium polysulfides and enhances catalytic conversion, effectively suppressing the polysulfide shuttling and leading to the long cycling stability of Li–S batteries.
Graphite, commonly including artificial graphite and natural graphite (NG), possesses a relatively high theoretical capacity of 372 mA h g–1 and appropriate lithiation/de‐lithiation potential, and ...has been extensively used as the anode of lithium‐ion batteries (LIBs). With the requirements of reducing CO2 emission to achieve carbon neutral, the market share of NG anode will continue to grow due to its excellent processability and low production energy consumption. NG, which is abundant in China, can be divided into flake graphite (FG) and microcrystalline graphite (MG). In the past 30 years, many researchers have focused on developing modified NG and its derivatives with superior electrochemical performance, promoting their wide applications in LIBs. Here, a comprehensive overview of the origin, roles, and research progress of NG‐based materials in ongoing LIBs is provided, including their structure, properties, electrochemical performance, modification methods, derivatives, composites, and applications, especially the strategies to improve their high‐rate and low‐temperature charging performance. Prospects regarding the development orientation as well as future applications of NG‐based materials are also considered, which will provide significant guidance for the current and future research of high‐energy‐density LIBs.
A comprehensive overview of natural graphite‐based materials in ongoing lithium‐ion batteries is presented, covering fundamental mechanisms, detailed applications, and an outlook of natural graphite‐based materials, from not only the aspects of structure and properties, modifications, derivatives, and composites, but also perspectives in terms of natural graphite in hybrid lithium‐ion/lithium‐metal cells and all‐solid‐state lithium batteries.
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