Fast Ion Diffusion Research Articles

Regulating Intercalation of Layered Compounds for Electrochemical Energy Storage and Electrocatalysis

AbstractLayered materials have received extensive attention for widespread applications such as energy storage and conversion, catalysis, and ion transport owing to their fast ion diffusion, exfoliative feature, superior mechanical flexibility, tunable bandgap structure, etc. The presence of large interlayer space between each layer enhances intercalation of the guest ion or molecule, which is beneficial for fast ion diffusion and charge transport along the channels. This intercalation reaction of layered compounds with guest species results in material with improved mechanical and electronic properties for efficient energy storage and conversion, catalysis, ion transport, and other applications. This review extensively discusses the intercalation of guest ionic or molecular species into layered materials used for various types of applications. It assesses the intercalation strategies, mechanism of ionic or molecular intercalation reactions, and highlights recent advancements. The electrochemical performances of several typical intercalated materials in batteries, supercapacitors, and electrocatalytic systems have been thoroughly discussed. Moreover, the challenges in the design and intercalation of layered materials, as well as prospects of future development are highlighted.

Binder-free 3D graphene nanostructures on Ni foam substrate for application in capacitive deionization

Hereby a simple, low-cost and scalable route is being presented for preparation of binder-free electrodes of reduced graphene oxide (RGO) on Ni foam (Ni/Gr). In this regard, the Ni foams are dipped in graphene oxide (GO) slurry. Next, the GO loaded Ni foams are kept in a freeze dryer for 24 h and heated up to 800 °C in an inert atmosphere. In this approach, the amount of active materials can be easily optimized for capacitive deionization (CDI). The characterization of Ni/Gr electrodes revealed a 3D porous assembly of RGO on Ni substrate which is helpful for the fast ion diffusion and rapid electron transport. The electrochemical performance of the prepared electrodes is investigated in both 3-electrode system and symmetric 2-electrode assembly. Then, the prepared electrodes are applied for capacitive deionization (CDI) studies in saline water samples. Results revealed a specific capacitance of about 77 F/g (in 1 M of NaCl at 2.5 A/g) and an ion removal capacitance of 22.3 mg/g (in 50 mL of 500 ppm of NaCl) for the fabricated system. The stability of the CDI system was surveyed in 500 ppm of NaCl solution which showed 65% of the initial capacity after 200 consecutive cycles (9 days). These results indicate that this method is efficient for both supercapacitive energy storage applications and CDI technology.

Synthesis of activated carbon from black liquor for the application of supercapacitor

In the present study, black liquor carbonization has been investigated by hydrothermal process. The activated carbon from the carbonization of black liquor (AC-BL) and biomass-based activated carbon from citrus sinensis flavedos (AC-OP) has been investigated for suitability in supercapacitor application. The study has analyzed the electrochemical measurement of both AC-BL and AC-OP in electrochemical stations. The role of stable hydroxyl molecules on the surface of carbon material has been observed and its effective conductivity is studied. The superior performance of AC-OP-derived nanoporous carbon has fast ionic and electronic diffusion of the electrolyte in and out of the pores during charging and discharging due to high surface area. AC-BL exhibited with an EDLC mechanism, but AC-OP shows the pseudocapacitance property. The porous structure and oxygen doping characteristics in AC-BL can influence the potential electrode material for applications in the field of supercapacitors. With the help of this movement, the electronic conductivity of the AC-BL has been increased. In general, the electrochemical stability of the EDLC is far better than the pseudocapacitor. From the GCD analysis, it is observed that the specific capacitance of 17.4 and 148.2 F g−1 is obtained from GCD spectra for AC-BL and AC-OP, respectively. From the EIS analysis, the ESR value is very small for AC-BL (60 Ω), when compared to AC-OP (155 Ω). To conclude that the EIS results of low conductivity by AC-BL have the potential to be future supercapacitors with enhanced treatment in carbonization techniques.

Ion exchange in atomically thin clays and micas.

The physical properties of clays and micas can be controlled by exchanging ions in the crystal lattice. Atomically thin materials can have superior properties in a range of membrane applications, yet the ion-exchange process itself remains largely unexplored in few-layer crystals. Here we use atomic-resolution scanning transmission electron microscopy to study the dynamics of ion exchange and reveal individual ion binding sites in atomically thin and artificially restacked clays and micas. We find that the ion diffusion coefficient for the interlayer space of atomically thin samples is up to 104 times larger than in bulk crystals and approaches its value in free water. Samples where no bulk exchange is expected display fast exchange at restacked interfaces, where the exchanged ions arrange in islands with dimensions controlled by the moiré superlattice dimensions. We attribute the fast ion diffusion to enhanced interlayer expandability resulting from weaker interlayer binding forces in both atomically thin and restacked materials. This work provides atomic scale insights into ion diffusion in highly confined spaces and suggests strategies to design exfoliated clay membranes with enhanced performance.

Three-dimensional graphene-like carbon nanosheets coupled with MnCo-layered double hydroxides nanoflowers as efficient bifunctional oxygen electrocatalyst

As a multifunctional material with excellent performances, layered double hydroxides (LDHs) and their composites have broad application prospects in energy storage, catalysis, environmental protection, drug release and other fields. In this study, three-dimensional (3-D) graphene-like carbon nanosheets (AGC) were prepared by one-step synthesis method as active carrier materials, and then MnCo-LDHs nanoflowers assembled with ultrafine nanosheets were loaded on them to construct a newly 3-D architecture of AGC/MnCo-LDHs nanocomposites. The nanocomposites were characterized by XRD, SEM, TEM and XPS. The composite materials were assembled into OER and ORR electrodes for electrochemical measurements as efficient bifunctional catalysts. The favorable 3-D porous architecture (fast ion diffusion) of MnCo-LDHs and carrier effect of AGC (high electron conductivity) were the key contributing factors for their excellent electrochemical performances of nanocomposites.

Hierarchical porous biomass-derived carbon framework with ultrahigh surface area for outstanding capacitance supercapacitor

A porous carbon framework is successfully synthesized from lycium chinensis via a novel strategy using melamine matched with KOH as dual-activator. The biomass-derived carbon framework with hierarchical macro-/meso-/micro pores demonstrates an ultrahigh surface area of 3344 m2 g−1 and a sufficient total pore volume of 1.71 cm3 g−1. The porous carbon electrode with optimized structure presents an outstanding electrochemical performance. The specific capacitance reaches 520.0 F g−1 at 1 A g−1 and 291.0 F g−1 at 30 A g−1 with 96.8 % capacitance retention after 10 000 cycles at 30 A g−1. The energy density is also as high as 12.5 W h kg−1 for the electrode. The relationship between optimized structure and excellent performance of carbon materials is deeply explored. The superior electrochemical performance of carbon framework can be ascribed to its hierarchical porosity, ultrahigh surface area, sufficient total pore volume, proper graphitization degree and favorable heteroatom-doping, which will result in the fast ion diffusion, sufficient charge storage as well as the contributed pseudocapacitance. The work provides an effective guidance for synthesizing the superb porous biomass-derived carbon materials for supercapacitor with high performance.

Rational Design of Hierarchical Mn-Doped Na5V12O32 Nanorods with Low Crystallinity as Advanced Cathodes for Aqueous Zinc Ion Batteries

Aqueous zinc ion batteries (ZIBs) have been regarded as one of the most promising candidates for large-scale energy storage systems. Herein, low crystallinity Mn-doped Na5V12O32 (NMVO) with hierarchical rodlike structure has been fabricated by a one-step hydrothermal method. Due to the rational design of the phase and micro/nanostructure, NMVO has numerous voids and defects, which are beneficial to the reversible insertion/extraction of zinc ions. When utilized as cathodes for ZIBs, the electrode delivers a capacity of 256.3 mAh g–1 after 50 cycles at 0.1 A g–1. Moreover, NMVO presents stable cycling performance and rate capability in electrolyte with the addition of Na2SO4. The kinetic characterizations and diffusion mechanism are also studied, and the results demonstrate that the superior zinc ion storage properties of NMVO can be attributed to the equal capacitive contribution, fast ion diffusion coefficient, and favorable structural stability. This strategy can be extended to other electrode materials, such as manganese-based materials and molybdenum-based materials, et al.

Chiral carbon nanotubes decorated MoS2 nanosheets as stable anode materials for sodium-ion batteries

Constructing carbon-based metal sulfides hybrids are efficient strategy for improving the sodium storage performance. And novel carbon materials are attractive in the development of electrodes. Herein, chiral amphiphiles are utilized to design chiral (C-CNTs) and straight (S-CNTs) nitrogen-doped CNTs through polycondensation and supramolecular assemble process, followed by pyrolysis. Besides, the CNTs can serve as skeleton, and MoS2 nanosheets are then anchored on the mesoporous CNTs matrix by hydrothermal reaction. Well-aligned architectures are obtained for MoS2/S-CNTs, while MoS2/C-CNTs are porous with short tubular morphology. As anode materials, MoS2/C-CNTs electrode outperforms the MoS2/S-CNTs counterparts and exhibits superior cycle stability and rate performances. It delivers a capacity of 368.8 mA h g−1 after 300 cycles at a high current density of 2 A g−1. Based on kinetics analysis, the percentage of capacitive charge storage is around 93.6% at the scan rate of 2 mV s−1. The phenomenon can be elucidated by the fast charge transfer resistance and small Warburg coefficient of MoS2/C-CNTs, which are superior to MoS2/S-CNTs. Therefore, the unique chiral structure combines the merits of expanded layer-spacing, nitrogen doping with high conductivity, and mesoporous channels, ensuring fast ion diffusion and pseudocapacitive behavior. This work provides an opportunity for fabricating other metal sulfides/C-CNTs SIBs anode materials with excellent cycling stability.

Bioinspired in situ self-catalyzing strategy towards graphene nanosheets with hierarchical structure derived from biomass for advanced supercapacitors

Ultrahigh-quality graphene with structural hierarchy has been successfully fabricated through a novel and effective bioinspired in situ self-catalyzing strategy with camphor leaves as a renewable carbon source. The intrinsic Ca-containing species in biomass transfers into CaO via the intermediate of CaCO3 during the pyrolysis process, and the finally imbedded CaO functions as in situ hard template and catalyst to generate hierarchical structure and construct the graphitic structure. The utilization of KOH effectively facilitated the graphene formation and enhanced the porosity of the carbon materials. The resultant graphene possesses many advantages for supercapacitor application, including large surface area, hierarchical porosity (crosslinked micro/meso/macroporous vacancies), well-organized graphene layers and favorable dually co-doping of O/N, thereby contributing to rapid charge transportation on the electrode/electrolyte interface, fast diffusion of electrolyte ions and high conductivity. When directly used as supercapacitor electrode (without the mixture of any conductive agent), as-produced graphene exhibited a specific capacitance of 397F/g at a current density of 1.0 A/g with a high rate retention of 74% from 1 to 20 A/g in a three-electrode system with 6 M KOH aqueous electrolyte. The high-quality graphene prepared from biomass via a readily scalable method opened up new vision towards high performance applications in energy storage and conversion.

Water‐Soluble Cross‐Linking Functional Binder for Low‐Cost and High‐Performance Lithium–Sulfur Batteries

AbstractBinders play an important role in battery systems. The lithium–sulfur (Li–S) batteries have poor cycling performance owing to large volume alteration of sulfur and shuttle effect. Herein, a novel water‐soluble functional binder (named GN‐BA) is prepared by the cross‐linking effect between gelatin and boric acid. The excellent binder can effectively maintain the integrated electrode stable, buffer the volume changes, prevent active materials exfoliation from current collectors, and anchor polysulfides by chemical bonding. Sulfur electrodes in this binder also exhibit a loosely stacked porous structure, which is advantageous to the electrolyte permeation and fast ion diffusion. X‐ray photoelectron spectroscopy, ultraviolet‐visible spectroscopy, and density functional theory calculations further verified that the binder can anchor polysulfides by forming BOLi, COLi, and CNLi chemical bonds. At 0.5 C, a high initial capacity of 980 mA h g−1 can be obtained, which is higher than those sulfur cathodes with traditional poly(vinylidene fluoride) binder. When the sulfur loading is up to 5.0 mg cm−2, a high areal specific capacity of 5.7 mA h cm−2 and excellent cycling stability are achieved. This study proposes an economical and environmentally friendly strategy for the construction of advanced binders and promotes the practical application of high‐energy Li–S batteries.

Porosity Engineering of MXene Membrane towards Polysulfide Inhibition and Fast Lithium Ion Transportation for Lithium-Sulfur Batteries.

Detrimental lithium polysulfide (LiPS) shuttle effects and sluggish electrochemical conversion kinetics in lithium-sulfur (Li-S) batteries severely hinder their practical application. Separator modification has been extensively investigated as an effective strategy to address above issues. Nevertheless, in the case of functional separators, how to effectively block the LiPSs from diffusion while enabling the rapid Li ion transport remains a challenge. Herein, by using an "oxidation-etching" method, MXene membranes are presented with controllable in-plane pores as interlayer to regulate Li ion transportation and LiPS immobilization. Porous MXene membranes with optimized pore density and size can simultaneously anchor LiPS and ensure fast Li ion diffusion. Consequently, even with pure sulfur cathode, the improved Li-S batteries deliver excellent rate performance up to 2 C with a reversible capacity of 677.6mAhg-1 and long-term cyclability over 500 cycles at 1 C with a low capacity decay of 0.07% per cycle. This work sheds new insights into the design of high-performance interlayers with manipulated nanochannels and tailored surface chemistry to regulate LiPSs trapping and Li ion diffusion in Li-S batteries.

Stabilizing voltage and prolonged cycling life of Li-rich Mn-based oxides through spinel “lithium ion pump” heteroepitaxial coating strategy

The practical application of Li-rich layered oxides is impeded by its cycle instability, poor rate capability and serious voltage decay. Here, nano-sized spinel Li4Ti5O12 (LTO) is constructed on Li1.2Ni0.13Co0.13Mn0.54O2 (LLNCMO). The distinctly heteroepitaxial structure of LTO nanocoating on LLNCMO is corroborated by HAADF-STEM. The LTO coating with fast lithium ion diffusion kinetics acts as “lithium ion pump” when Li+-ions cross over it. The integrated structure can effectively retard oxygen evolution and phase transformation engendering higher capacity and voltage retention. LTO heteroepitaxially coated LLNCMO (LTO@LLNCMO) shows an improvement of initial coulombic efficiency to 74.3% and more stable life with a high capacity retention up to 96.9% at 2C after 500 cycles (40.5% for LLNCMO). LTO@LLNCMO demonstrates minimal voltage fading of 1.33 mV per cycle suggesting suppression of phase conversion to spinel-like structure. The epitaxial spinel modification strategy can be applied to control the surface stability of cathodes.

Value-added apple-derived carbonaceous aerogel for robust supercapacitor

Fe3O4 nanocrystals ornamented CdO nanorods were successfully grown over the apple waste-based carbonaceous activated aerogel through hydrothermal and calcination techniques. The high surface area, crystalline nature, strong magnetization, and numerous functional groups make it a potential candidate for energy storage devices owing to fast ions diffusion, facile electron transportation, and outstanding synergism between metals. The resulted supercapacitor achieved a maximum 40 W h/kg energy density at 1000 power density W/kg and excellent cycling stability of 93.68% capacitance retention after 1100 charge/discharge cycles. These discoveries have opened the use of cost-effective biomass-based composite materials and provide possibilities for their application in the field of sustainable energy storage.

PrBaCo2O5+δ-Sm0.5Sr0.5CoO3 Composite Oxide as Active Cathode for Intermediate-Temperature Solid Oxide Fuel Cells

Cathodic performance of double perovskite oxide of PrBaCo2O5 as an active catalyst for SOFC was investigated. Because delamination of PrBaCo2O5 cathode is easily occurred by larger thermal expansion coefficient, mixing effects of PrBaCo2O5 with another perovskite oxide were investigated using a LaGaO3-based electrolyte. Among the oxides mixed with PrBaCo2O5 (PBCO), it was found that mixing Sm0.5Sr0.5CoO3 (SSC) with PBCO shows the smallest cathodic overpotential and the most suitable for increase in cathodic activity. Increase in cathodic performance can be assigned to the high activity of oxygen dissociation on SSC and the fast oxide ion diffusivity in PBCO. Therefore, composite oxide of PBCO with SSC is highly active as cathode for SOFC at intermediate temperature.

Alkali-Rich Antiperovskite M3FCh (M = Li, Na; Ch = S, Se, Te): The Role of Anions in Phase Stability and Ionic Transport.

To improve ionic conductivity, solid-state electrolytes with polarizable anions that weakly interact with mobile ions have received much attention, a recent example being lithium/sodium-rich antiperovskite M3HCh (M = Li, Na; Ch = S, Se, Te). Herein, in order to clarify the role of anions in antiperovskites, the M3FCh family, in which the polarizable H- anion at the octahedral center is replaced by the ionic F- anion, is investigated theoretically and experimentally. We unexpectedly found that the stronger attractive interaction between F- and M+ ions does not slow down the M+ ion diffusion, with the calculated energy barrier being as low as that of M3HCh. This fact suggests that the low-frequency rotational phonon modes of the octahedron of cubic M3FCh (and M3HCh) are intrinsic to facilitate the fast ionic diffusion. A systematic analysis further reveals a correlation between the tolerance factor t and the ionic transport: as t decreases within the cubic phase, the rotational mode becomes softer, resulting in the reduction of the migration energy. The cubic iodine-doped Li3FSe has a room-temperature ionic conductivity of 5 × 10-5 S/cm with a bulk activation energy of 0.18 eV.

Ti3C2-MXene composite films functionalized with polypyrrole and ionic liquid-based microemulsion particles for supercapacitor applications

Stemming from its unique structure and properties, Ti3C2-MXenes have stood out from the crowd of electrode materials due to effectively ameliorating imperfections of common ones for excellent energy storage. However, a major stumbling block in the further development of MXene-based supercapacitors is the inherent low capacities caused by severe restacking of nanosheets. Herein, we develop a simple, effective and innovative strategy, namely, introducing both polymerized polypyrrole (PPy) particles and ionic liquid (ILs)-based microemulsion particles as “dual spacers”, to fabricate functionalized Ti3C2-MXene composite films for high-performance and wide-temperature application in supercapacitors. The PPy particles acting as one “spacer” circumvent restacking issues of MXene nanosheets, while contribute to desirable capacitance of the hybrid material. ILs-based microemulsions spontaneously adsorbing onto PPy-Ti3C2Tx nanosheets are conceived to be one more liquid “spacer” for fast ion diffusion kinetics and absent electrolyte imbibition steps, which is rarely reported in previous research for MXene-based electrode materials. These features endow the composite films with excellent specific capacitance, rate capability and cycling stability between 4 °C and 50 °C. At room temperature, the symmetric supercapacitor device based on the composite films delivers a maximum gravimetric energy density of 31.2 Wh kg−1 (at 1030.4 W kg−1) and reserves 91% of the initial specific capacitance with a coulombic efficiency of 91% after 2000 cycles. All these impressive results substantiate that the composite films prepared by ingenious structure design showcase huge potentials in advanced MXene-based supercapacitors using various ionic liquid electrolytes.

Design and synthesis of 2D rGO/NiO heterostructure composites for high-performance electrochromic energy storage

Two-dimensional (2D) transition metal oxide composited with graphene has attracted worldwide attention in the energy storage and conversation field. Here, a 2D rGO/NiO heterostructure film on ITO glass was designed and applied to electrochromic energy storage. The 2D heterostructure increases the interlayer spacing of the NiO-based films and the electrochemically active surface area, reduces the charge transfer resistance and band gap, and then realizes fast ion diffusion and electron transport, thus improving the electrochromic and supercapacitor performance of the NiO film. The film exhibits outstanding areal capacitance (269 mF cm−2 at current density of 0.5 mA cm−2), excellent cyclic stability (capacitance retention almost 100% after 1000 cycles at current density of 1.5 mA cm−2) and superior electrochromic performance (high optical contrast of 53% at 630 nm, fast response time of 3.4 s for coloration and 5.3 s for bleaching). Furthermore, integrated the 2D heterostructure rGO/NiO film into a smart electrochromic-supercapacitor device, two devices could light up an electronic watch for about 2 h, at the same time, the color of the device changes in the process of electric output.

Chemically Treated Activated Carbon for Supercapacitor Electrode Derived from Starch of Solanum Tuberosum

Because of the increasing demands in energy, growth in alternate energy sources is inevitable. By activation followed by carbonization of starch of solanum tuberosum makes a porous carbon network as electrode material for supercapacitor. To achieve an improvement in specific capacitance, activating the starch of solanum tuberosum using chemicals such as hydrochloric acid, phosphoric acid and sulphuric acid were done. The structural and electrochemical performance of activated carbon derived from the starch of solanum tuberosum is evaluated using FTIR, XRD, CV, GCD and EIS. The improved performance of chemically treated starch of solanum tuberosum in energy storage mechanism is ascribed to fast ionic diffusion of the electrolyte into and out of the pores. From the CV analysis, the higher specific capacitance (94 F.g-1) is obtained for sulphuric acid treated activated carbon derived from the starch of solanum tuberosum with good capacity retention ratio. From GCD analysis, 78.3, 56.7, 82.7 and 74.9 Fg-1 of specific capacitance is obtained for POC, POCH, POCP and POCS, respectively. When compared to all the prepared samples, POC exhibited small equivalent series resistance and POCS exhibited small charge transfer resistance.

Chlorinated dual-protective layers as interfacial stabilizer for dendrite-free lithium metal anode

Lithium metals offer great promises to achieve higher energy density beyond conventional lithium-ion batteries (LIBs) because of its ultrahigh specific capacity (3860 mAh g−1) and the lowest reduction potentials (-3.04 V vs. standard hydrogen electrode). Unfortunately, the application of lithium metal anode has been long-standingly handicapped by uncontrollable dendrite growth, which induces instable solid electrolyte interface (SEI), performance degradation and thermal runaway. Herein, a compositionally favorable and structurally robust dual-protective layer (DPL) is proposed, where at the bottom, in-situ formed LiCl film provides sufficient rigidity (6.5 GPa) and low Li+ diffusion barriers (0.09 eV) against dendrite growth. The poly(vinylidene fluoride-hexafluoropropylene) (PVdF-HFP) gel-electrolyte as the top layer is rationally selected with high flexibility to accommodate volume variation. Due to the synergy of DPL, the instability of interface is ultimately regulated to favor an extremely stabilized SEI with enhanced Li+ diffusion kinetics. Depth profiling of X-ray photoelectron spectroscopy (XPS) revealed a spontaneously-formed gradient SEI hierarchy, a first-of-this-kind structure that enables long-term cycle stability and high rate capability. Cryo-electron microscopy (cryo-EM) provides direct proof on the formation of halide-rich SEI interlayers that strengthen the interfacial stability during cycles. As a consequence, dendrite-proof lithium deposition, critical Li+ flux and fast ion-diffusion kinetics have been synergistically achieved to greatly improve the high-rate cycle stability (10 mA cm−2), high Coulombic efficiency (99.5%), and prolonged cycle lifespan (1600 h) for lithium metal batteries (LMBs). The design of DPL from this contribution has opened up opportunities of lithium chlorides in purpose of constructing dendrite-free and Li+ permeable interface, and provided insights for the realization of high energy density LMBs.

Assembly of Defect-Free Microgel Nanomembranes for CO2 Separation.

The development of robust and thin CO2 separation membranes that allow fast and selective permeation of CO2 will be crucial for rebalancing the global carbon cycle. Hydrogels are attractive membrane materials because of their tunable chemical properties and exceptionally high diffusion coefficients for solutes. However, their fragility prevents the fabrication of thin defect-free membranes suitable for gas separation. Here, we report the assembly of defect-free hydrogel nanomembranes for CO2 separation. Such membranes can be prepared by coating an aqueous suspension of colloidal hydrogel microparticles (microgels) onto a flat, rough, or micropatterned porous support as long as the pores are hydrophilic and the pore size is smaller than the diameter of the microgels. The deformability of the microgel particles enables the autonomous assembly of defect-free 30-50 nm-thick membrane layers from deformed ∼15 nm-thick discoidal particles. Microscopic analysis established that the penetration of water into the pores driven by capillary force assists the assembly of a defect-free dense hydrogel layer on the pores. Although the dried films did not show significant CO2 permeance even in the presence of amine groups, the permeance dramatically increased when the membranes are adequately hydrated to form a hydrogel. This result indicated the importance of free water in the membranes to achieve fast diffusion of bicarbonate ions. The hydrogel nanomembranes consisting of amine-containing microgel particles show selective CO2 permeation (850 GPU, αCO2/N2 = 25) against post-combustion gases. Acid-containing microgel membranes doped with amines show highly selective CO2 permeation against post-combustion gases (1010 GPU, αCO2/N2 = 216) and direct air capture (1270 GPU, αCO2/N2 = 2380). The membrane formation mechanism reported in this paper will provide insights into the self-assembly of soft matters. Furthermore, the versatile strategy of fabricating hydrogel nanomembranes by the autonomous assembly of deformable microgels will enable the large-scale manufacturing of high-performance separation membranes, allowing low-cost carbon capture from post-combustion gases and atmospheric air.