Guiding the lithium ion (Li‐ion) transport for homogeneous, dispersive distribution is crucial for dendrite‐free Li anodes with high current density and long‐term cyclability, but remains challenging ...for the unavailable well‐designed nanostructures. Herein, we propose a two‐dimensional (2D) heterostructure composed of defective graphene oxide (GO) clipped on mesoporous polypyrrole (mPPy) as a dual‐functional Li‐ion redistributor to regulate the stepwise Li‐ion distribution and Li deposition for extremely stable, dendrite‐free Li anodes. Owing to the synergy between the Li‐ion transport nanochannels of mPPy and the Li‐ion nanosieves of defective GO, the 2D mPPy‐GO heterostructure achieves ultralong cycling stability (1000 cycles), even tests at 0 and 50 °C, and an ultralow overpotential of 70 mV at a high current density of 10.0 mA cm−2, outperforming most reported Li anodes. Furthermore, mPPy‐GO‐Li/LiCoO2 full batteries demonstrate remarkably enhanced performance with a capacity retention of >90 % after 450 cycles. Therefore, this work opens many opportunities for creating 2D heterostructures for high‐energy‐density Li metal batteries.
A 2D heterostructure of mesoporous polypyrrole grown on defective graphene oxide was used as a dual‐functional lithium ion redistributor with stepwise lithium ion distribution and homogeneous lithium deposition for extremely stable, dendrite‐free lithium anodes. This design takes advantage of the synergistic effects arising from the lithium ion transport nanochannels of mesoporous polypyrrole and the defective graphene oxide acting as a lithium ion nanosieve.
Planar integrated systems of micro‐supercapacitors (MSCs) and sensors are of profound importance for 3C electronics, but usually appear poor in compatibility due to the complex connections of device ...units with multiple mono‐functional materials. Herein, 2D hierarchical ordered dual‐mesoporous polypyrrole/graphene (DM‐PG) nanosheets are developed as bi‐functional active materials for a novel prototype planar integrated system of MSC and NH3 sensor. Owing to effective coupling of conductive graphene and high‐sensitive pseudocapacitive polypyrrole, well‐defined dual‐mesopores of ≈7 and ≈18 nm, hierarchical mesoporous network, and large surface area of 112 m2 g−1, the resultant DM‐PG nanosheets exhibit extraordinary sensing response to NH3 as low as 200 ppb, exceptional selectivity toward NH3 that is much higher than other volatile organic compounds, and outstanding capacitance of 376 F g−1 at 1 mV s−1 for supercapacitors, simultaneously surpassing single‐mesoporous and non‐mesoporous counterparts. Importantly, the bi‐functional DM‐PG‐based MSC‐sensor integrated system represents rapid and stable response exposed to 10–40 ppm of NH3 after only charging for 100 s, remarkable sensitivity of NH3 detection that is close to DM‐PG‐based MSC‐free sensor, impressive flexibility with ≈82% of initial response value even at 180°, and enhanced overall compatibility, thereby holding great promise for ultrathin, miniaturized, body‐attachable, and portable detection of NH3.
2D hierarchical ordered dual‐mesoporous polypyrrole/graphene nanosheets are demonstrated as bi‐functional active materials for the planar micro‐supercapacitor‐sensor‐integrated system on one single substrate, unveiling high electrochemical performance, exceptional flexibility, and high NH3 response, which will pave the way to developing ultrathin, miniaturized, flexible, and self‐powered electronics.
High‐efficiency lithium–sulfur (Li–S) batteries depend on an advanced electrode structure that can attain high sulfur utilization at lean‐electrolyte conditions and minimum amount of lithium. Herein, ...a twinborn holey Nb4N5–Nb2O5 heterostructure is designed as a dual‐functional host for both redox–kinetics–accelerated sulfur cathode and dendrite‐inhibited lithium anode simultaneously for long‐cycling and lean‐electrolyte Li–S full batteries. Benefiting from the accelerative polysulfides anchoring–diffusion–converting efficiency of Nb4N5–Nb2O5, polysulfide‐shutting is significantly alleviated. Meanwhile, the lithiophilic nature of holey Nb4N5–Nb2O5 is applied as an ion‐redistributor for homogeneous Li‐ion deposition. Taking advantage of these merits, the Li–S full batteries present excellent electrochemical properties, including a minimum capacity decay rate of 0.025% per cycle, and a high areal capacity of 5.0 mAh cm−2 at sulfur loading of 6.9 mg cm−2, corresponding to negative to positive capacity ratio of 2.4:1 and electrolyte to sulfur ratio of 5.1 µL mg−1. Therefore, this work paves a new avenue for boosting high‐performances Li–S batteries toward practical applications.
A holey Nb4N5‐Nb2O5 heterostructure is designed as a dual‐functional host for both the sulfur‐cathode and lithium‐anode for lithium‐sulfur full‐batteries. The polysulfide‐shutting is significantly alleviated as the accelerative polysulfides anchoring‐diffusion‐converting efficiency of the interface. A homogeneous lithium‐ion deposition is realized as the lithiophilic holey ion‐redistributor. The designed lithium‐sulfur full batteries present excellent electrochemical properties at high sulfur loading and lean electrolyte conditions.
A dual-stimulus-driven stiff-stilbene-based dynamic 3rotaxane has been facilely developed using the threading-stoppering strategy and exhibits reversible shuttling motions and bidirectional rotations ...upon encountering acid-base and distinct light stimulations, respectively. Herein, the two dibenzo-24-crown-8 macrocycles can undergo reversible switching motion between two different stations along the axle suffered from acid-base stimulation, and simultaneously, the two rotaxanes can also perform
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rotations upon irradiation with distinct light. In other words, the constructed rotaxanes can conduct two modes of regular motions without interference. Interestingly, reciprocating switching motion of the rings along the axle enabled the rotaxanes to exhibit controllable and reversible photoisomerization speed, conversion yield, and quantum yield. Crucially, these rotaxanes also manifest adjustable solid-state organic room-temperature phosphorescence (RTP) and photoluminescence stimulated by dual factors (acid-base and diverse light), which are further applied in information encryption and anticounterfeiting. The presented study provides an instructive way for precisely boosting photoisomerization performances and the fabrication of dual-stimuli-induced molecular machines with functions of two-mode mechanical motions and controllable pure organic RTP switches.
Designing oxygen catalysts with well-defined shapes and high-activity crystal facets is of great importance to boost catalytic performance of Li–O2 batteries but challenging. Herein, we report the ...facet engineering of an ultrathin Mn3O4 nanosheet (NS) with dominant (101) crystal planes on graphene (Mn3O4 NS/G) as efficient and durable oxygen catalysts for high-performance Li–O2 batteries with ultrahigh capacity and long-term stability. Notably, the Mn3O4 NS/G with the (101) facets and enriched oxygen vacancies offers a lower charge overpotential of 0.86 V than that of Mn3O4 nanoparticles on graphene (1.15 V). Further, the Mn3O4 NS/G cathode exhibits a long-term stability over 1300 h and an ultrahigh specific capacity up to 35,583 mAh g–1 at 200 mA g–1, outperforming most Mn-based oxides for Li–O2 batteries reported. Both the experimental and theoretical results prove the lower adsorption energy of Mn3O4 (101) for Li2O2 in comparison with Mn3O4 (211), manifesting the easier decomposition of Li2O2 during the charging process. This work will open many opportunities to engineer Mn-based materials with a defined crystal facet for high-performance Li–O2 batteries.
Abstract
The rapid development of printed and microscale electronics imminently requires compatible micro-batteries (MBs) with high performance, applicable scalability, and exceptional safety, but ...faces great challenges from the ever-reported stacked geometry. Herein the first printed planar prototype of aqueous-based, high-safety Zn//MnO2 MBs, with outstanding performance, aesthetic diversity, flexibility and modularization, is demonstrated, based on interdigital patterns of Zn ink as anode and MnO2 ink as cathode, with high-conducting graphene ink as a metal-free current collector, fabricated by an industrially scalable screen-printing technique. The planar separator-free Zn//MnO2 MBs, tested in neutral aqueous electrolyte, deliver a high volumetric capacity of 19.3 mAh/cm3 (corresponding to 393 mAh/g) at 7.5 mA/cm3, and notable volumetric energy density of 17.3 mWh/cm3, outperforming lithium thin-film batteries (≤10 mWh/cm3). Furthermore, our Zn//MnO2 MBs present long-term cyclability having a high capacity retention of 83.9% after 1300 cycles at 5 C, which is superior to stacked Zn//MnO2 batteries previously reported. Also, Zn//MnO2 planar MBs exhibit exceptional flexibility without observable capacity decay under serious deformation, and remarkably serial and parallel integration of constructing bipolar cells with high voltage and capacity output. Therefore, low-cost, environmentally benign Zn//MnO2 MBs with in-plane geometry possess huge potential as high-energy, safe, scalable and flexible microscale power sources for direction integration with printed electronics.
The bottom-up assembly utilizing nanocrystals (NCs) as building blocks is a highly anticipated approach to access novel metamaterials. Limited by the library of binary spherical assembly, colloidal ...components of building blocks are necessarily extended for targeting the desired assembled-superstructure with emergent properties. Here, a generalized approach is presented that carbon nanotubes (CNTs) capped with long-chain hydrocarbon ligands, as creative colloidal components, can be compatibly co-assembled with various NCs into binary supraspheres based on a confinement microemulsion environment. Such cross-dimensional assemblies possess the structural merits of excellent conductivity, abundant voids and high stability, thus synergistically boosting its electrochemical performance. As a proof of concept, the co-assembled CoFe2O4/CNTs supraspheres exhibit extraordinary capacity (890 mAh g−1 at 0.5 A g−1), rate capability (318 mAh g−1 at 20 A g−1), and structural stability (458 mAh g−1 at 5 A g−1 after 1000 cycles) relative to pure CoFe2O4 when evaluated in Li-ion battery. Beyond that, its derived phosphides CoFeP/CNTs assemblies outperform most of the state-of-art electrodes when acting as electrocatalysts for hydrogen evolution reactions (HER). This work provides a new perspective for constructing superstructures of NCs for potential applications in energy storage devices.
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A low-cost scalable strategy is developed to fabricate lignin derived hierarchical porous carbon as a high-loading Se host. When combined with carbonate-based electrolyte, the high-capacity and ...long-term cycling Li–Se batteries were obtained.
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Lithium–selenium (Li–Se) batteries have attracted considerable attentions for next-generation energy storage systems owing to high volumetric capacity of 3265 mAh cm−3 and excellent electronic conductivity (~10−5 S cm−1) of selenium. However, the shuttling effect and capacity fading prevent their wide applications. Herein we report a low-cost strategy for scalable fabrication of lignin derived hierarchical porous carbon (LHPC) as a new high-loading Se host for high-capacity and long-term cycling Li–Se batteries in carbonate electrolyte. The resulting LHPC exhibits three-dimensional (3D) hierarchically porous structure, high specific surface area of 1696 m2 g−1, and hetero-atom doping (O, S), which can effectively confine the Se particles into the micropores, and meanwhile, offer effective chemical binding sites for selenides from hetero-atoms (O, S). As a result, our Li–Se batteries based on Se@LHPC demonstrate high capacity of 450 mAh g−1 at 0.5 C after 500 cycles, with a low capacity fading rate of only 0.027%. The theoretical simulation confirmed the strong affinity of selenides on the O and S sites of LHPC effectively mitigating the Se losing. Therefore, our strategy of using lignin as the low-cost precursor of hierarchically porous carbon for high-loading Se host offers new opportunities for high-capacity and long-life Li–Se batteries.
Sodium ion batteries (SIBs) for large-scale grid applications are facing great challenges in terms of development of high-performance electrode materials and screening of suitable electrolytes. ...Herein, a versatile and scalable protocol for synthesizing two-dimensional (2D) holey cobalt sulfide (h-Co 4 S 3 ) nanosheets is demonstrated for high-rate and long-life SIBs in an ether-based electrolyte of 1.0 M NaCF 3 SO 3 in diglyme. The 2D h-Co 4 S 3 nanosheets are prepared by sulfuration of leaf-like cobalt based metal–organic frameworks (CoMOFs), and subsequent annealing treatment. Benefiting from the nanosheet nature of in-plane nanopores (10–30 nm), ultra-thinness (<30 nm), crumpled morphology, and micron-scale lateral size that can provide more active sites and enhanced sodiation/desodiation kinetics, the resulting h-Co 4 S 3 nanosheets achieve a high reversible capacity of 571 mA h g −1 at 0.1 A g −1 , and long-life cycling stability with a retention of 80% after 400 cycles for SIBs. Furthermore, theoretical simulation reveals the enhanced structural stability of h-Co 4 S 3 nanosheets with a lower binding energy (0.31 eV) of the Co–O bond in the ether-based electrolyte than that in the carbonate-based electrolyte. Notably, the h-Co 4 S 3 anode offers an exceptional rate capacity of 257 mA h g −1 at 12 A g −1 , outperforming most reported cobalt sulfide-based anodes. This strategy will pave a new way to rationally construct MOF-derived 2D nanostructures for various energy-related applications.
In the era of the Internet of Things and wearable electronics, 3D-printed micro-batteries with miniaturization, aesthetic diversity and high aspect ratio, have emerged as a recent innovation that ...solves the problems of limited design diversity, poor flexibility and low mass loading of materials associated with traditional power sources restricted by the slurry-casting method. Thus, a comprehensive understanding of the rational design of 3D-printed materials, inks, methods, configurations and systems is critical to optimize the electrochemical performance of customizable 3D-printed micro-batteries. In this review, we offer a key overview and systematic discussion on 3D-printed micro-batteries, emphasizing the close relationship between printable materials and printing technology, as well as the reasonable design of inks. Initially, we compare the distinct characteristics of various printing technologies, and subsequently emphatically expound the printable components of micro-batteries and general approaches to prepare printable inks. After that, we focus on the outstanding role played by 3D printing design in the device architecture, battery configuration, performance improvement, and system integration. Finally, the future challenges and perspectives concerning high-performance 3D-printed micro-batteries are adequately highlighted and discussed. This comprehensive discussion aims at providing a blueprint for the design and construction of next-generation 3D-printed micro-batteries.
Recent advances and present status of 3D-printed micro-batteries with respect to the connection between printable materials and printing techniques, as well as the rational design considerations are summarized.
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