Coulombic Efficiency Research Articles

Nickel sulfide nanoparticles decorated on carbon spheres derived from Verbena officinalis for high-performance asymmetric all-solid-state flexible supercapacitors

The crafting and development of electrode materials possessing extensive energy storage capacities, alongside their adherence to environmental and economic principles, along with their outstanding capacitive behaviors, stand as pivotal elements in propelling the technological progress of supercapacitors. In this study, we utilized discarded Verbena officinalis (VOCs) as a carbon substrate and successfully synthesized porous hollow carbon spheres through an in-situ hydrothermal method, subsequently depositing NiS nanoparticles to form a shell-like structured material. The optimized VOCs/NiS-3 composite material exhibited an exceptional specific capacitance of 202.8 mAh g−1 at a current density of 1.0 A g−1; it maintained 71 % of its capacitance even at a high current density of 10 A g−1 (144.2 mAh g−1). After enduring 10,000 charge-discharge iterations, the preservation of charge storage capacity was 81.7 %, highlighting the material's outstanding performance in terms of rapid charge-discharge rates and enduring stability. Furthermore, within a PVA/KOH gel electrolyte, we fabricated an asymmetric all-solid-state supercapacitor device that delivered an energy density of 32.58 Wh k g−1 at a power density of 800 W k g−1. The device sustained a capacitance loss rate of 9.9 % and a coulombic efficiency of 96.8 % after 5000 cycles. Even after 3000 repeated bending at 120°, the capacitance retention reached 88.3 %, indicating the device's exceptional specific capacitance, flexibility and longevity. This research offers a renewable and waste-resource recycling design strategy for synthesizing outstanding-performance, flexible, all-solid-state supercapacitor electrode materials with NiS deposited on discarded biomass carbon, unveiling considerable potential for enhancing energy storage efficiency.

Enhancing aqueous zinc-ion energy storage performance with ion-mediating carbon quantum dots-modified separators regulating zinc deposition behavior

Aqueous zinc-ion batteries (AZIBs) hold promising applications owing to their safety, cost-effectiveness, and competitive capacity. However, issues such as zinc dendritic formation and side reactions severely impede their practical viability. Utilizing carbon quantum dots (CQDs) to modify cheap, tenacious, and highly hydrophilic filter paper (FP) as separator effectively improves the electrochemical performance of zinc ion energy storage systems. The structured arrangement of CQDs redistributes zinc ion transport and induces uniform zinc icon deposition, thereby improving zinc ion reaction kinetics. Moreover, the rich functional groups on the surface of CQDs readily form hydrogen bonds with active H2O, further inhibiting corrosion reactions. With the assistance of CQDs, the FP-CQDs separator maintains high ionic conductivity and a high zinc-ion transference number, ensuring dendrite-free and corrosion-resistant operation with high coulombic efficiency and a prolonged lifespan of 1200 h at 1 mA cm−2. Zn//AC hybrid capacitors incorporating FP-CQDs separator demonstrate superior capacity retention compared to those using FP separator alone, with a high capacity retention after 600 cycles at 1 A/g, while Zn//V2O5 full batteries also exhibit excellent cycling stability. Given these findings, this study presents a new composite separator for advanced aqueous zinc-ion energy storage systems.

Highly reversible Zn anodes enabled by in-situ construction of zincophilic zinc polyacrylate interphase for aqueous Zn-ion batteries

The irreversibility and low utilization of Zn anode stemming from the corrosion and dendrite growth have largely limited the commercialization of aqueous zinc batteries. Here, a carbonyl-rich polymer interphase of zinc polyacrylate (ZPAA) is spontaneously in-situ constructed on Zn anode to address the above-mentioned dilemmas. The ZPAA interlayer enables fast transport kinetics of Zn2+ and tailors the interfacial electric field for realizing the uniform Zn deposition due to superior zincophilicity, high Zn2+ transference number and inherent ion-diffusion channel. Importantly, acting as a buffer interphase with strong adhesion and isolation of electrolytes, this functional layer effectively protects the Zn electrode against the water-induced erosion and passivation. Remarkably, the ZPAA@Zn electrode realizes an enhanced Coulombic efficiency of 99.71 % within 2200 cycles, delivers an ultra-long cycling stability over 7660 h (>319 days, 1 mA cm−2) and 2460 h (5 mA cm−2) with lower voltage hysteresis. Also, the ZPAA@Zn/MnO2 full cell maintains a high capacity of 114 mAh/g after 2000 cycles, much better that of untreated Zn/MnO2 cell (25 mAh/g). This concept of in-situ fabricating ion-sieve-like polymer interphase provides a facile approach to stabilize Zn anode and further paves a way for high-performance aqueous batteries.

Mildly expanded graphite with exceptional performance from waste lithium ion batteries by space-confined intercalation of deep eutectic solvent

Reclaiming the spent graphite (SG) in the anodes of end-of-life lithium-ion batteries (LIBs) is of tremendous significance for addressing resource shortage and eco-friendliness. The impurities embedded into the graphite interlayer after multiple charge–discharge cycles hinder the free migration of lithium ions, resulting in inferior lithium storage capacity. Herein, a space-confined intercalation of deep eutectic solvent (DES) strategy is proposed, to dissolve the impurities by utilizing its great ability to form hydrogen bonds (O–H…Cl-, O–H…O and O–H…F) with PVDF binder, SEI film and the residual electrolytes within the SG, simultaneously enlarging the interlayer distance to upgrade the anode graphite. After the further pyrolysis, the as-obtained mildly expanded graphite (MEG-800) exhibited well-defined graphite microcrystalline layer structure and high graphitization degree. The moderately enlarged graphite layers provided more space for the insertion and extraction of lithium ions, endowing MEG-800 with exceptional performance in LIBs, such as extremely high charge capacity of 477.4 mAh/g at a current density of 0.1 A/g and superior reversibility and desirable cycle stability. After 100 cycles at 0.1 A/g, its capacity still retained 470.9 mAh/g with a Coulombic efficiency as high as 99.76 %. The structure-dependent lithium-ion diffusion features of MEG-800 were also examined by electrochemical kinetics analysis. This study opened up a prospective avenue for the green and efficient recycling of spent anode graphite in retired LIBs, offering a solution to the problem of shortage of battery materials and promoting sustainable development.

Fabrication of functional laser-induced graphene using gelatin-2,6-diaminoanthraquinone coating for high-performance micro-supercapacitor

In this investigation, we develop a procedure in which gelatin and 2,6-diaminoanthraquinone (ANQ) are combined and then applied as a coating on laser-induced graphene (LIG). The resulting materials are subjected to laser irradiation, which facilitates the introduction of nitrogen doping and the integration of oxygenated functional groups onto the LIG surface. The gelatin polymer played a pivotal role in introducing oxygenated functional groups, while ANQ molecules contributed to both doping with nitrogen and the inclusion of additional oxygenated groups on the LIG surface. The electrode material's performance was enhanced by these functional groups. When evaluated in a three-electrode setup, the ANQ-LIG configuration exhibited a significantly high areal capacitance of 32.4 mF cm−2 at 0.2 mA cm−2, which is five times that of pristine LIG (6.3 mF cm−2) and three times that of gelatin-LIG (9.0 mF cm−2). When integrated into a micro-supercapacitor using a polyvinyl alcohol (PVA)-sulfuric acid (H2SO4) gel electrolyte, ANQ-LIG demonstrated superior areal capacitance (16.0 mF cm−2 at 0.1 mA cm−2) compared to gelatin-LIG (5.3 mF cm−2) at the same current. Additionally, ANQ-LIG displayed favorable capacitance retention (83.8 % after 10,000 cycles) and coulombic efficiency (98.1 % after 10,000 cycles).

Concentrated precipitation electrolyte for reviving ultrathin lithium metal anode

Realizing high-performance lithium metal batteries requires the presence of a robust solid-electrolyte interphase (SEI) on the Li metal surface that forms before or during operation. Herein, high concentrations of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and lithium nitrite (LiNO3) are employed to create a novel concentrated precipitation electrolyte (CPE) and form an inorganic-rich SEI. It is found that an ultrathin Li metal anode (thickness of 25 μ m) in the CPE remains highly reversible over 300 cycles with an average Coulombic efficiency (CE) of 97.21 % in an asymmetric Cu|Li cell. The CPE enables superior stability to the LiFePO4 (LFP) cathode at a high mass loading of ∼15 mg cm−2 and reaches a capacity retention of 82.8 % after 100 cycles with an average CE of 99.94 %. This study elucidates the mechanism of LiTFSI and LiNO3 in enhancing the physiochemical properties of the SEI surface layer. It is believed that this design concept and the findings can be broadened to optimize SEIs via electrolyte engineering for practical Li metal batteries.

Engineering p-d orbital hybridization in PdSb bimetallene for energy-saving H2 production parallel upgrade plastic waste

The electrochemical conversion of PET-derived ethylene glycol into high-quality chemicals parallel energy-saving H2 production is an optimal solution to the serious environmental pollution of plastics. In this paper, p-d orbital hybrid PdSb bimetallene with defect-rich crimped surface is synthesized by a one-step solvent approach. PdSb bimetallene exhibits excellent electrocatalytic performance in ethylene glycol and PET hydrolysate oxidation attributed to the unconventional p-d orbital hybridization feature and metallene structure. PdSb bimetallene shows better properties than Pd metallene and commercial Pd black catalysts under ethylene glycol conditions and PET hydrolysate. Besides PdSb bimetallene can oxidize ethylene glycol to produce the valuable product glycolic acid with high Faradaic efficiency and selectivity. Besides, PdSb bimetallene can oxidize PET-derived ethylene glycol into glycolic acid with high selectivity in EGOR||HER system. This study provides insights into the synthesis of metallene with p-d orbital hybridization properties, coupled with energy-saving H2 production parallel upgrade plastic waste.

Promoting active hydrogen supply for kinetically matched tandem electrocatalytic nitrate reduction to ammonia

Electrocatalytic nitrate reduction (NO3RR) shows admirable potential for environmental remediation and producing valuable NH3. However, the catalyst is restricted by the kinetic mismatch between NO3--to-NO2- and NO2--to-NH3, which results in excess NO2- and poor NH3 selectivity. Herein, a kinetically matched tandem electrocatalytic strategy with tunable active hydrogen(*H) supply is designed. The combination of Cu2O and Co11(HPO3)8(OH)6 (CoPO) playing key roles in NO3RR by i) on-demand supply of *H from CoPO; ii) the electronically coupled interface between Cu2O and CoPO enhance *H transfer kinetics. The Cu2O-CoPO-2 exhibits high NH3 yield of 22 mg cm−2 h−1 with Faradaic efficiency of 95 % at −0.37 V vs. RHE. In situ characterizations indicate the dynamic equilibrium between *H production and consumption contributes to high NO3RR performance. The techno-economic analyses reveal the system is economically viable compared to Haber-Bosch (H-B) process, which benefits from industrial current densities and superior energy efficiency at low potentials.

Green synthesis of CoVS2-MOF@CMS nanocomposite electrode for sustainable approach towards eco-friendly energy storage and dopamine detection

Dopamine, a crucial brain chemical belonging to the catecholamine and phenethylamine chemical families, plays a vital role in promoting a healthy and happy life. Irregular dopamine release has been linked to various neurological disorders and depressive conditions. Therefore, conducting real-time, in vivo monitoring of dopamine levels is essential to gain a comprehensive understanding of its physiological functions. In this research, the hydrothermal technique was employed to synthesize copper‑molybdenum sulfide (Cu2MoS4 (CMS)). Further, we have reported the one-pot hydrothermal synthesis of CoVS2-MOF, using the bioactive chemical as fuel obtained from Euphorbia cognata Boiss. The specific capacity (Qs) of the sample CoVS2-MOF@CMS was calculated to be 820 Cg−1 at 3 mVs−1, a value expressively higher than that of the reference samples. Furthermore, in the supercapattery device, an outstanding Qs of 300 Cg−1 was achieved at 1.5 Ag−1, surpassing the previously observed values. The device demonstrated outstanding performance, including a coulombic efficiency of 89 %, a specific energy of 36.68 Whkg−1, and a power density (Pd) of 2218.53 Wkg−1. Moreover, the sensor typically yielded dopamine (DA) concentrations in human serum ranging from 100.8 % to 102.2 %. The utilization of the multifunctional CoVS2-MOF@CMS nanocomposite electrode material illustrates promising prospects for the fabrication of hybrid devices with applications in biomedical and energy harvesting fields.

Pitch-based carbon anode for high-energy and long-life sodium-ion battery

Pitch-based carbon generally demonstrate remarkable electrochemical performance for sodium-ion batteries (SIBs). In this paper, the medium temperature pitch is successively subjected to heat treatment under high pressure, extraction of toluene to remove soluble matter, and carbonization of toluene insoluble matter, to prepare the anode material, named pitch toluene insoluble anode (PTIA). The PTIA is characteristic of the coral-like morphology distributed with 100−200 nm pore channels and 2−3 nm mesopores for electrolyte immersion, and the disordered carbon structure is interwoven with graphitic carbon for sodium-ion insertion/desertion and electron transmission. In the PTIA half battery, the reversible specific capacity reaches 276.9 mAh g−1 at 0.1 A g−1 after 300 cycles with a coulombic efficiency of 99.22%. Importantly, the PTIA exhibits good compatibility with vanadium sodium phosphate (NVP) cathode materials, enabling a battery PTIA//NVP to achieve a capacity density of 154 mAh g−1, an energy density of 246.7 Wh kg−1 and a power density of 4800 W kg−1 for 1000 cycles at a current density of 3 A g−1 (16−18 C). The battery has a certain working efficiency at -10−70°C.

Zwitterionic hydrogels with high interfacial affinity for zinc metal batteries

Zinc metal batteries are expected to be the next generation of energy storage devices due to their high safety, but their application is hampered by irreversible hydrogen evolution reaction and surface side reactions of zinc anodes. Here, a zwitterionic hydrogel electrolyte is reported based on polymerization of acrylamide and 1-(3-Sulfopropyl)-2-Vinylpyridinium betaine, and it exhibits the following advantages: the sulfonic acid group of 1-(3-Sulfopropyl)-2-Vinylpyridinium betaine can be preferentially adsorbed on metal Zinc to avoid side reactions and refine the affinity at the zinc-electrolyte interface; and the coordination of the negatively charged sulfonic acid group with Zn2+ alters the solvation structure of Zn2+, which further improves the restriction ability of side reactions. Consequently, Zn||Zn symmetric batteries can be stabilized for 1, 200 h of plating stripping at 1 mA cm−2. Zn||Cu batteries exhibit an impressive average coulombic efficiency of 99.8 % over a remarkable span of 1, 800 cycles at a current density of 15 mA cm−2. Furthermore, the Zn||MnO2/Carbon nanotube batteries have been cycled more than 2, 000 cycles at a current density of 0.5 A g−1, and the zinc hybrid capacitors for more than 18, 000 cycles at 1 A g−1. And an ionic skin (i-skin) based on acrylamide and 1-(3-Sulfopropyl)-2-Vinylpyridinium betaine of polymer hydrogel electrolyte is assembled and it can stably detect physiological signals.

CoO nanoparticles anchored on porous pinecone-derived activated carbon as anodes for high-performance lithium and sodium-ion batteries

In this work, a new nanocomposite system based on CoO nanoparticles (NPs) anchored on pinecone-derived activated carbon (PAC), denoted as CoO(x)@PAC, is synthesized by facile ball-milling and sonication processes followed by annealing. H3PO4 is employed as an activation agent to activate the porous carbon derived from pinecone. The loading amount of CoO is varied to obtain the optimum electrochemical performances. Among the nanocomposites, the CoO(20)@PAC delivers a discharge capacity of 886 mA h g−1 after 100 cycles at a current density of 100 mA g−1 when employed as an anode in lithium-ion batteries (LIBs). At higher current rate of 1000 mA g−1, the anode provides an enhanced discharge capacity of 456.6 mA h g−1 after 200 cycles with 99 % capacity retention compared to the 4th cycle capacity. In sodium-ion batteries (SIBs), the CoO(20)@PAC anode delivers a discharge capacity of 290 mA h g−1 at 50 mA g−1. The same nanocomposite anode provides a discharge capacity of 120 mA h g−1 after 900 cycles at a current density of 500 mA g−1. The CoO(20)@PAC nanocomposite shows a great potential as an anode for both LIBs and SIBs, due to its higher capacity, exceptional rate capability, longer cycle life, and a Coulombic efficiency exceeding 99 %.

Enhancing the Electrocatalytic Oxidation of 5-Hydroxymethylfurfural Through Cascade Structure Tuning for Highly Stable Biomass Upgrading.

Electrocatalytic 5-hydroxymethylfurfural oxidation reaction (HMFOR) provides a promising strategy to convert biomass derivative to high-value-added chemicals. Herein, a cascade strategy is proposed to construct Pd-NiCo2O4 electrocatalyst by Pd loading on Ni-doped Co3O4 and for highly active and stable synergistic HMF oxidation. An elevated current density of 800mAcm-2 can be achieved at 1.5V, and both Faradaic efficiency and yield of 2,5-furandicarboxylic acid remained close to 100% over 10 consecutive electrolysis. Experimental and theoretical results unveil that the introduction of Pd atoms can modulate the local electronic structure of Ni/Co, which not only balances the competitive adsorption of HMF and OH- species, but also promote the active Ni3+ species formation, inducing high indirect oxidation activity. We have also discovered that Ni incorporation facilitates the Co2+ pre-oxidation and electrophilic OH* generation to contribute direct oxidation process. This work provides a new approach to design advanced electrocatalyst for biomass upgrading.

Structure–activity relationship of a dual-function amine-based electrolyte for integrated CO2 capture and electrochemical conversion

Integrated carbon dioxide (CO2) capture and electrocatalytic reduction processes through dual-function amine-based electrolytes and their integration into a single reactor can lead to significant energy savings, simplified process flow, and reduced transportation risks. This work investigates the structure–activity relationship of dual-functional amine-based electrolytes for CO2 capture and electrocatalytic reduction and develops an efficient dual-functional amine-based electrolyte system. We investigated 10 different amine-based solutions for their CO2 capture and reduction performances. The substituents on the nitrogen atom of the intermediate carbamate and the positions of the hydroxyl and branched groups affect the capture and electrochemical reduction. The 1,3-propanediamine system demonstrated enhanced CO2 solubility uptake (58.1 %), Faradaic efficiency (10.6 %), and current density (52.1 %) compared with the monoethanolamine system, indicating its potential as a dual-function amine-based electrolyte. Furthermore, density functional theory calculations indicated that the charge distribution of carbamate and the dissociation of C–N bonds directly influence the adsorption of carbamates on the electrode surface and the Faradaic efficiency of the reduced products. In addition, reaction path analysis based on the zwitterionic mechanism indicated that intermediates (carbamate R1R2NCOO-) with higher electronegativity are more conducive to adsorb onto the electrode surface and inhibit hydrogen generation from protonated amines (R1R2NHH+). The results suggest that the selection or design of dual-functional amine-based electrolytes should prioritize amines with straight alkanol chains rather than branched ones, which do not form intramolecular hydrogen bonds or heterocyclic structures. This work provides directions and guidance for designing and developing dual-functional electrolytes for integrated carbon capture and electrocatalytic conversion technologies.

Biocompatible and capacitive PDA-Ov-Co3O4@CC anode augmented exoelectrogens enrichment and extracellular electron transfer in microbial fuel cells

Metal oxides rich in oxygen vacancies (Ov) possess excellent intrinsic conductivity, variable valence metal center and high capacitance, which were potential candidates as microbial fuel cells anode. However, their high bacterial toxicity greatly hindered the activity of biofilm. To solve this issue, in this work, polydopamine (PDA) covered capacitive Ov doped Co3O4 nanosheets were designed and successfully grown on carbon cloth (CC). The introduction of Ov significantly promoted the charge storage, the net charge and the accumulated charge were 217.1 and 2680.3 C/m2, respectively, surpassed Co3O4 anode without Ov. In addition, Ov also decreased the charge-transfer resistance (Rct), effectively accelerating EET. The Rct of PDA/Ov-Co3O4@CC was 29.51 Ω, lower than CC (382.10 Ω). The cover of PDA prevented the direct contact between metal ions and microorganisms, greatly enhanced the bacterial viability. The power density of MFCs with PDA/Ov-Co3O4@CC anode was 2.77 W/m2, 1.45 times higher than that of bare CC (1.90 W/m2). In addition, PDA/Ov-Co3O4@CC anode displayed excellent coulombic efficiency and daily COD removal amount (23.5 % and 147.6 mg/L/d), higher than the control groups. The community analysis showed the abundance of Geobacter on PDA/Ov-Co3O4@CC anode was 91 %, higher than other anodes. Present study developed a facile and effective PDA coating strategy to simultaneously enhance the biocompatibility and capacitance of Ov-rich metal oxides, which will be a promising method for the preparation of high performance MFCs anode.

Covalent triazine frameworks crosslinked microporous polymer membranes with fast and selective ion transport for ultra-stable vanadium redox flow batteries

The vanadium redox flow batteries (VRFBs) are an essential pathway to long-duration energy storage with the merits of power and energy decoupling, long lifetime and safety. However, low coulombic efficiency stemming from vanadium crossover across the membrane together with notable ohmic loss originated from low proton conductivity of the membrane still limits high performance operation of the VRFBs. Herein, we proposed 2,2′-bipyridine-based covalent triazine frameworks (bipCTF) crosslinked sulfonated-poly (4,4′-diphenylether-5,5′-bibenzimidazole) (SOPBI) (bipCTF/SP-100) for use as the membrane in VRFBs, which synergistically prevents vanadium crossover and enhances proton conductivity. By delicately tuning the sulfonation degree and properly incorporate bipCTF, the bipCTF/SP-100 membrane is successfully synthesized based on OPBI polymers, which delivers a reduced area resistance of 0.3 Ω cm2 and a low VO2+ permeability of 19.05 × 10−9 cm2 s−1, affording an excellent trade-off between proton conductivity and ion selectivity. Theoretical calculation further corroborates that the high proton conductivity of bipCTF/SP-100 is attributed to the ionic channels formed by bipCTF, while the superior ion selectivity is assigned to protonated imidazole and pyridine. Benefiting from microporous bipCTF/SP-100 membrane, the VRFB exhibits a high CE of 99.8 % and an excellent EE of 78.3 % at 250 mA cm−2 and meanwhile yields a high capacity retention of 94.8 % after 200 cycles at 200 mA cm−2, which shows enormous potential for high power density operation of the VRFBs.

A Cu-Zn bimetallic organic framework as protective interlayer for dendrite-free Zn deposition in zinc-based flow batteries

Zinc-based flow batteries hold great promise for grid-scale energy storage. However, the formation of zinc dendrites challenges their lifespan and safety. In this work, we devise a bimetallic organic framework material on carbon cloth (CuZn@MOF-CC) using a one-step dip coating method to address the dendrite issue. The prepared CuZn@MOF-CC promotes the creation of zincophilic sites on the electrode surface, facilitating smooth and uniform zinc deposition. Electrochemical csharacterizations and density functional theory (DFT) calculations reveal much stronger electronic interactions between CuZn@MOF and the zinc atoms compared to the commonly used anode material through an obvious electron interaction between the Zn atom and the Cu sites linked in the CuZn@MOF chain. By mitigating the zinc dendrite problem, this approach effectively improves the coulombic efficiency, cycle life, and safety of zinc-based flow batteries. The battery incorporating the prepared material demonstrates impressive stability, exceeding 450 cycles without dendrites at a high current density of 320 mA cm−2, paving the way for efficient and reliable energy storage solutions and a sustainable future.

Converting a low-cost industrial polymer into organic cathodes for high mass-loading aqueous zinc-ion batteries

Aqueous zinc-ion batteries (AZIBs) using organic cathodes have emerged as a sustainable energy storage technology benefitting from high safety, low cost, and abundant feedstocks. However, most organic cathodes are n-type polyaromatic compounds and conjugated polymers, which require sophisticated synthesis, provide a low operational voltage and slow Zn2+ diffusion kinetics. Herein, we report access to p-type radical polymer cathodes from a commercially available poly(methyl vinyl ether-alt-maleic anhydride) (poly(MVE-alt-MA)) polymer. The modification of poly(MVE-alt-MA) with 4-amino-TEMPO produces radical polymers (PTEMPO) that are easily scalable to tens of grams. The corresponding polymer AZIBs deliver a capacity of 92 mAh g-1 at 10 C with 95 % capacity retention over 1000 cycles. Importantly, the electrode composites and battery assembly procedure are optimised so that no fluoro-containing electrolytes and binders are needed, and cheap carbon additives can be used. We assemble the Swagelok batteries, small pouch, and large pouch batteries with a high mass-loading of 7.8 to 50 mg cm-2, demonstrating nearly 100 % Coulombic efficiency. The pouch battery with 0.8–0.9 g of active polymer displayed a 60-mAh capacity with 1.5 V operational voltage. This work paves the way for simple and practical implementation of polymer AZIBs for real-world applications.

Regulation of Molecular Microheterogeneity in Electrolytes Enables Ampere-Hour-Level Aqueous LiMn2O4||Li4Ti5O12 Pouch Cells.

Aqueous batteries are attractive due to their high safety and fast reaction kinetics, but the narrow electrochemical stability window of H2O limits their applications. It is a big challenge to broaden the electrochemical operation window of aqueous electrolytes while retaining fast reaction kinetics. Here, a new organic aqueous mixture electrolyte of manipulatable (3D)molecular microheterogeneity with H2O-rich and H2O-poor domains is demonstrated. H2O-poor domains molecularly surround the reformed microclusters of H2O molecules through interfacial H-bonds, which thus not only inhibit the long-range transfer of H2O but also allow fast and consecutive Li+ transport. This new design enables low-voltage anodes reversibly cycling with aqueous-based electrolytes and high ionic conductivity of 4.5 mS cm-1. LiMn2O4||Li4Ti5O12 full cells demonstrate excellent cycling stability over 1000 cycles under various C rates and a low temperature of -20°C. 1 Ah pouch cell delivers a high energy density of 79.3Wh kg-1 and high Coulombic efficiency of 99.4% at 1 C over 200 cycles. This work provides new insights into the design of electrolytes based on the molecular microheterogeneity for rechargeable batteries.

Liquid template synergizing combustion activation to construct vesicular porous carbon anode for sodium ion batteries

In this study, B, N and O tri-doped porous carbon material (EBNK) is successfully prepared by liquid template synergistic combustion activation. Benefiting from this method, the generated EBNK exhibits a unique vesicle-like spherical shell structure, which significantly accelerates the transport of sodium ions, and therefore the initial coulombic efficiency of its half-cells in ether-based electrolyte is as high as 95.6 %. Moreover, the synergistic effect of the three dopant atoms increases the number of defects and the spacing of the carbon layers, resulting in the EBNK anode exhibiting rare and excellent properties. The specific capacity is 487.5 mAh/g at 0.05 A/g, and 125 mAh/g at 50 A/g; the capacity is maintained at 138.9 mAh/g after 5500 cycles at 20 A/g. The NVP//EBNK full cell has an energy density of 192.2 Wh kg−1 at a power density of 159.7 W kg−1. This study will undoubtedly expand the methods for preparing sodium-ion batteries with excellent performance, provide new perspectives on the energy storage mechanism of multi-doped porous carbon, and promote the development of the energy storage field.