High Conductive Electrolyte Research Articles

Self-healing single-ion-conductive artificial polymeric solid electrolyte interphases for stable lithium metal anodes

Unstable solid-electrolyte interphase (SEI) layer, accompanied with detrimental Li dendrite growth, is the major challenge for realizing viable Li metal batteries. Herein, we report a self-healing and single-ion conductive artificial SEI (SS-ASEI) layer to stabilize Li metal anode, suppress the Li dendrite growth and promote the Li plating/stripping kinetics. The polymeric SS-ASEI layer is optimized to be dynamically cross-linked poly(dimethylsiloxane) filled with 7 wt% SiO2 nanoparticles. The modified Li symmetric cell achieves extremely stable plating/stripping cycling for 1340 h at 0.5 mA cm−2 and 1.0 mAh cm−2 cutting-off capacity. Superior rate capability and cycling stability of the modified anode are also demonstrated in cells with commercial NCM811 (LiNi0.8Co0.1Mn0.1O2) cathode. The self-healing ability, elastic deformation capability, selectively high Li-ion conductivity and low liquid electrolyte swelling rate of our SS-ASEI layer synergistically account for the superior performances of modified Li electrode over the bare Li electrode.

Bi-Cu bimetallic electrocatalysts prepared using electrochemical deposition effluent for highly converting CO2 to formate

Developing bimetallic electrocatalysts with synergistic effect is a promising strategy to facilitate the electrocatalytic reduction of CO2 (ECR-CO2). Electrodeposition strategy due to its convenience and time-saving property has been widely used in ECR-CO2, however, the disadvantage of electrodeposition method is the treatment of electroplating liquid waste. Aiming for recovering metal ions from electroplating liquid waste and developing high-performance catalysts for ECR-CO2, a bimetallic Bi3Cu1 is synthesized by green-cleaning method. The Bi3Cu1 catalyst exhibits a promising formate (HCOO-) faradaic efficiency (FE) of 95.1% at −0.75 V vs. RHE in an H-type cell. Moreover, excellent durability is also obtained, maintaining a high FEHCOO- of 89.4% after 20 h electrolysis. In addition, the experimental results show that the KOH is a better choice than the KHCO3 electrolyte for ECR-CO2. Bi3Cu1 shows enhanced current density and FE of formate, owing to the faster mass transport in the gas-fed continuous-flow cell and the high ionic conductivity of KOH electrolyte.

Interface Engineering on Cellulose-Based Flexible Electrode Enables High Mass Loading Wearable Supercapacitor with Ultrahigh Capacitance and Energy Density.

For practical energy storage devices, a bottleneck is to retain decent integrated performances while increasing the mass loading of active materials to the commercial level, which highlights an urgent need for novel electrode structure design strategies. Here, an active nitrogen-doped carbon interface with "high conductivity, high porosity, and high electrolyte affinity" on a flexible cellulose electrode surface is engineered to accommodate 1D active materials. The high conductivity of interface favors fast electron transport, while its high porosity and high electrolyte affinity properties benefit ion migration. As a result, the flexible anode accommodated by carbon nanotubes achieves an ultrahigh capacitance of 9501 mF cm-2 (315.6 F g-1 ) at a high mass loading of 30.1mg cm-2 , and the flexible cathode accommodated by polypyrrole nanotubes realizes a remarkably high capacitance of 6212 mF cm-2 (248 F g-1 , 25mg cm-2 ). The assembled flexible quasi-solid-state asymmetric supercapacitor delivers a maximum energy density of 1.42 mWh cm-2 (2.2V, 2105 mF cm-2 ), representing the highest value among all reported flexible supercapacitors. This versatile design concept provides a new way to prepare high performance flexible energy storage devices.

Flexible Electron-Rich Ion Channels Enable Ultrafast and Stable Aqueous Zinc-Ion Storage.

Aqueous zinc-ion batteries (ZIBs) are regarded as a promising candidate for ultrafast charge storage owing to the high ionic conductivity of aqueous electrolytes and high theoretical capacity of zinc metal anodes. However, the strong electrostatic interaction between high-charge-density zinc ions and host materials generally leads to sluggish ion-transport kinetics and structural collapse of rigid cathode materials during the charge/discharge process, so searching for suitable cathode materials for ultrafast and long-term stable ZIBs remains a great challenge. Herein, flexible electron-rich ion channels enabling fast-charging and stable aqueous ZIBs have been demonstrated. Because of the nitrogen-rich conjugated structure of organic phenazine (PNZ) molecules, electron-rich ion channels are formed with the C═N redox centers situated on the channel surface, where zinc ions can transport rapidly and react with active moieties directly. Meanwhile, the π-conjugated systems and inherent flexibility of PNZ molecules can accommodate rapid strain changes and maintain their structural stability during zinc-ion intercalation/deintercalation. Consequently, they exhibit a high capacity of 94.2 mAh g-1 at an ultrahigh rate of 700C (208.6 A g-1) and an ultralong life over 100,000 cycles at 100C, which are superior to those of previously reported aqueous ZIBs. Our work presents a new way for developing ultrafast and ultrastable aqueous ZIBs.

Predicting Li-Rich Layered Oxide Compounds as High-Conductivity and Stable Solid Electrolytes

Predicting Li-Rich Layered Oxide Compounds as High-Conductivity and Stable Solid Electrolytes

A Novel Strategy to Overcome the Hurdle for Commercial All-Solid-State Batteries via Low-Cost Synthesis of Sulfide Solid Electrolytes.

Unlike commercial lithium-ion batteries, the high cost and low ionic conductivity of solid electrolytes (SEs) continues to be a big hurdle in commercially available all-solid-state batteries (ASSBs). Rather than the conventional dry-process and high-energy ball milling processes, the productive solution synthesis of bulk-type SEs is the most crucial issue in the successful application of high-energy-density ASSBs. In this study, the way is paved to overcome the hurdle for commercial lithium phosphorus sulfide chloride (LPSCl) SEs via a readily processable bulk-type solution-based synthesis without acquiring any high-energy ball-milling processes. By incorporating an elemental sulfur additive during the preparation process, Li2 S and S form a polysulfide, and P2 S5 is induced to react readily to provide LPSCl with excellent ion conductivity as high as 1.8 mS cm-1 . Surprisingly, the purity of bulk type precursors does not affect the final composition and ionic conductivity of sulfide electrolytes, which show the same electrochemical characteristics of ASSB cells with a high discharge capacity of 185.6 mA h g-1 . The study offers a promising strategy for saving the production cost of sulfide SEs, possibly up to 92%, and their commercial ASSBs are expected to be achieving a competitive cost per energy density of ≈0.46 $ W-1 .

Solid-state batteries designed with high ion conductive composite polymer electrolyte and silicon anode

Polymer solid-state batteries (SSBs) possess the advantages of good interfacial contact, but their application faces low ionic conductivity. Here, three-dimensional (3D) porous composite polymer electrolytes with propylene carbonate plasticizer (3D-PPLLP-CPEs) fabricated effectively, displaying high ionic conductivity even at room temperature. Electrochemical in-situ polymerization of 3D-PPLLP-CPEs occurs during the first discharge process, avoiding safety issues caused by the liquid plasticizer without sacrificing the ionic conductivity of the electrolyte. Besides, the controllable in-situ generated LiF-enriched interface can avoid the Li dendrite growth. To further promote the practical value of SSBs, micro-sized Si@Li3PO4@C with high initial Coulombic efficiency was adopted to replace lithium foil. The LiNi1/3Co1/3Mn1/3O2 (NCM111)//Micro Si@Li3PO4@C full cell has achieved capacity of 129.1 mAh g−1 at a current density of 0.2 C, with capacity retention of 98.5% after 100 cycles, which is the best performance based on the Si anode in SSBs. Even at the high current density of 2.0 A g−1, the capacity remains 92.5 mAh g−1. This design of CPEs and electrodes has paved a new way to construct practical SSBs.

Diphenyl Azidophosphate as a Functional Electrolyte Additive for High-Conductivity Film Construction over Lithium Metal Battery

Lithium metal batteries (LMBs) with high loading and high current density can be achieved by tailoring electrolyte components. As an effective film-forming electrolyte additive, diphenyl azidophosphate (DPPA) has been proposed here to construct high conductive solid electrolyte interphase (SEI) layers on the Li metal anode surface enriched with Li3N and P–O compounds. Compared with cells without DPPA additive, the Li∣∣Cu cells with 1% DPPA demonstrate evaluated accurate Coulombic efficiency (CE) from 77.9% to 93.8%, and Li∣∣Li symmetric cells are able to cycle for more than 250 h at the current density of 2 mA cm−2. The high conductive SEI layer increases the exchange current density of Li metal anode from 0.247 mA cm−2 to 0.760 mA cm−2. The Li∣∣LiNi0.8Co0.1Mn0.1O2 (NCM811) cell maintain 80.8% capacity retention after 250 cycles in the DPPA-containing electrolyte. Discharge capacity of the Li∣∣NCM811 cell can reach 142 mA h g−1 at a high discharge current of 13.2 mA cm−2. Further theoretical calculations indicate that the DPPA additive can be preferentially reduced to form a stable SEI layer with high conductivity.

High Performance Low-Temperature Solid Oxide Fuel Cells Based on Nanostructured Ceria-Based Electrolyte.

Ceria based electrolyte materials have shown potential application in low temperature solid oxide fuel cells (LT-SOFCs). In this paper, Sm3+ and Nd3+ co-doped CeO2 (SNDC) and pure CeO2 are synthesized via glycine-nitrate process (GNP) and the electro-chemical properties of the nanocrystalline structure electrolyte are investigated using complementary techniques. The result shows that Sm3+ and Nd3+ have been successfully doped into CeO2 lattice, and has the same cubic fluorite structure before, and after, doping. Sm3+ and Nd3+ co-doped causes the lattice distortion of CeO2 and generates more oxygen vacancies, which results in high ionic conductivity. The fuel cells with the nanocrystalline structure SNDC and CeO2 electrolytes have exhibited excellent electrochemical performances. At 450, 500 and 550 °C, the fuel cell for SNDC can achieve an extraordinary peak power densities of 406.25, 634.38, and 1070.31 mW·cm−2, which is, on average, about 1.26 times higher than those (309.38, 562.50 and 804.69 mW·cm−2) for pure CeO2 electrolyte. The outstanding performance of SNDC cell is closely related to the high ionic conductivity of SNDC electrolyte. Moreover, the encouraging findings suggest that the SNDC can be as potential candidate in LT-SOFCs application.

A Flexible Semi-Interpenetrating Network-Enhanced Ionogel Polymer Electrolyte for Highly Stable and Safe Lithium Metal Batteries.

An ionogel polymer electrolyte (IGPE), which combines the merits of high ionic conductivity and excellent safety property of a liquid electrolyte and a solid electrolyte, respectively, has shown great prospects in the application of a new generation of lithium secondary batteries. However, the increase in the ionic conductivity of IGPE will inevitably be at the expense of reduced mechanical strength, and this dilemma limits its application and market promotion. Here, an IGPE with a semi-interpenetrating cross-linked network structure was synthesized by UV-cross-linking to tackle this plight. The optimal sample ME82 shows an excellent ionic conductivity of 1.19 mS cm-1 at room temperature and robust mechanical strength (breaking strength: 1.55 MPa, elongation at break: 259%). Therefore, the assembled LiFePO4/ME82/Li cion cell displays an outstanding initial specific discharge capacity of 160.9 mAh g-1 at 55 °C 0.5 C, with a capacity retention of 94.00% after 200 cycles. In addition, ME82-based flexible batteries can withstand bending, folding, and even shearing abuse, which indicates that ME82 has application potentials in flexible electronic devices.

A Non-Flammable Zwitterionic Ionic Liquid/Ethylene Carbonate Mixed Electrolyte for Lithium-Ion Battery with Enhanced Safety.

Today, the requirement for clean, highly efficient, and safe energy seems to be higher and higher due to non-renewable energy and pollution of the environment. At this moment, lithium-ion batteries (LIBs) look like a reliable solution for this dilemma since they have huge energy density. However, the flammability of the conventional electrolyte used in the LIBs is one of critical disadvantages of LIBs, which compromises the safety issue of LIBs. Herein, we reported a non-flammable zwitterionic ionic liquid-based electrolyte named TLPEC, which was fabricated by simply mixing a novel zwitterionic ionic liquid TLP (93 wt%) and ethylene carbonate (EC, 7 wt%). The TLPEC electrolyte exhibited a wide electrochemical potential window of 1.65–5.10 V and a robust ionic conductivity of 1.0 × 10−3 S cm−1 at 20 °C, which renders TLPEC to be a suitable electrolyte for LIBs with enhanced safety performance. The LIBs, with TLPEC as the electrolyte, exhibited an excellent performance in terms of excellent rate capability, cycling stability, and high specific capacity at 25 and 60 °C, which were attributed to the stability and high ionic conductivity of TLPEC electrolyte during cycling as well as the excellent interface compatibility of TLPEC electrolyte with lithium anode.

Evaluation of Physicochemical Properties and Battery Performancesfor PEO/SL-Based Na Conductive Solid Electrolyte

Introduction In recent years, power generations utilized renewable energy are attracted attention, and power resource is variegated for the realization of sustainable society. Among them, the amount of power generation as solar power generation and wind power generation is unstable due to weather and environmental factors. In order to popularize such renewable energy, it is considered required to have a power storage system for stores the generated power electricity. As one of the promising candidates for them, there is the lithium-ion battery which is widely utilized such as smartphones and laptop computers. However, this battery has the problem such as cost and resource due to utilizing rare material of lithium and is desired to instead another element to lithium. Sodium resources are inexhaustible and distributed everywhere, it has similar chemical properties due to same monovalent alkali metal like lithium. One of the sodium-based batteries is the sodium-sulfur (Na-S) battery, which operates at high temperatures and is primarily used for peak-shaving and load-leveling applications. In general, sodium-sulfur (Na-S) batteries use sodium and sulfur as negative and positive electrode active materials, respectively, and has possible to produced low-cost due to few resource restrictions of the main content materials. The β-alumina ceramics are used as an electrolyte and acts as the Na+-conduction membrane layer and the separator between two liquid state electrodes. Due to operating at high temperature, it utilizes the advantage of quit high ionic conductivity of electrolyte at high temperature and improves the interfacial formation of electrolyte/electrode by ensuring active materials are molten. However, β-alumina is easy to damage by various thermal and mechanical stresses and there are risks of the direct reaction of molten sodium and sulfur, and leak out of the module. Therefore, it is desired to develop low temperature operating Na-S battery, we focused on solid polymer electrolytes (SPE) having high flexibility for the realization of safety low temperature operating Na-S battery. SPE is expected to improve safety by decrease operating temperature, but it has the problem of low ionic conductivity at room temperature to compare liquid electrolytes, therefore we focused on gel polymer electrolyte (GPE) by added sulfolane (SL) solvent which high thermal stability. This study proposed sodium conductive new solid polymer electrolytes and evaluated their physicochemical properties and Na-S battery performance. Experimental Liquid electrolytes were prepared by mixing SL and NaTFSA using shading bottle in Ar-filled glove box. The molar ratio was changed to xSL:1NaTFSA (x=2,3,4,5 and 6, respectively). These liquid electrolytes and polyether-based macromonomer (P(EO)/(PO), polymer) were mixed with changing weight ratio as followed formula; y liquid electrolyte: (10-y) polymer (y=7 and 8). After added DMPA as photo-initiator, solid gel polymer electrolytes were fabricated by photo-polymerization by UV irradiation. Prepared samples were expressed as (xSL)yEl+(10-y)Po. Thermophysical properties of fabricated gel polymer electrolytes were evaluated by thermogravimetric analysis (TG) and differential scanning calorimeter analysis (DSC). In addition, ionic conductivities were measured by electrochemical impedance method. The reversibility of Na-S batteries was evaluated by charge and discharge measurements at 333 K. Result and discussion Proposed GPE has high flexibility at room temperature. Remarkable weight changes were not observed below 373 K, and it was expected to apply as the low-temperature operated Na-S battery. Fig.1 shows DSC curves of GPE. The glass tradition temperature (T g) increased with polymer composition, when the case of high composition SL, T g exhibited almost the same value as T g of the pure polymer without SL. It was suggested that the increase in free PEO chains owing most Na+ forms a solvate structure with SL. Fig.2 shows temperature dependence of ionic conductivities. Ionic conductivities increased with SL composition, it was suggested that improving ionic mobility due to decreasing microscopic viscosity according to adding SL. The highest ionic conductivity of 2.3 × 10-3 Scm-1 was observed when the highest electrolyte composition and SL composition were optimized. In this presentation, we will also report about electrochemical properties, such as transference number of Na+ and activation energy at Na/GPE interfaces, time dependences of interfacial stabilization at Na/GPE interface, and battery performance of [Na|GPE|SPAN] (Sodium-Sulfur) and [Na|GPE|NaCoO2] (Na-ion) cells. Figure 1

An In Situ Artificial Cathode Electrolyte Interphase Strategy for Suppressing Cathode Dissolution in Aqueous Zinc Ion Batteries.

Rechargeable aqueous zinc ion batteries have attracted increasing attention as a new energy storage system because of the high ionic conductivity and safe aqueous electrolyte. The spontaneous vanadium dissolution in aqueous electrolytes is one major problem because the water with serious polarity would corrode the crystal structure of vanadium-based cathodes. Here, an in situ artificial cathode electrolyte interphase (CEI) strategy is proposed to kinetically suppress the vanadium dissolution in aqueous zinc ion batteries. The strontium ion is introduced into vanadium oxide layers as a sacrifice guest, which would directly precipitate upon getting out from the vanadium-based cathode to in situ from a CEI coating layer on the surface. This strategy is proven with the help of various technologies, and the remarkable ability of the CEI layer to suppress cathode dissolution is evaluated by multiple electrochemical and chemical methods. As a result, the cathode after CEI conversion exhibits the best recharge capacity retention after open circuit voltage rest for 3 days in comparison with other cathodes. This work reports a general strategy to construct the electrode-electrolyte interface for suppressing vanadium-based cathodes dissolution in aqueous electrolytes and beyond.

Study on the Farmland Improvement Effect of Drainage Measures under Film Mulch with Drip Irrigation in Saline–Alkali Land in Arid Areas

Water scarcity and imbalances in irrigation and drainage are the main factors leading to soil salinization in arid areas. There is a recognized need for effective drainage measures to prevent and improve saline−alkali land. The principal objective of this project was to investigate the effects of drainage measures on soil desalination and farmland drainage in the process of improving saline–alkali soils; these measures included subsurface pipe drainage (SPD) and open ditch drainage (ODD). The results of the tests, conducted over two years, revealed that the soil desalination rate in the SPD test area was between 25.8% and 35.2%, the cotton emergence rate was 36.7%, and a 3.8 t hm−2 seed cotton yield could be obtained. The soil electrolytic conductivity (EC) decreased step by step over time, and the average annual decrease reached 10 dS m−1. The degree of soil salinization was reduced from a moderately saline soil level (8−15 dS m−1) to a weakly saline soil level (4–8 dS m−1). Thus, the phased goal of improving saline–alkali land was achieved. The soil desalination rate in the ODD test area was only 1/10 of the SPD area; high soil EC (9−12 dS m−1) and groundwater level (2–3 m) were the most limiting factors affecting cotton growth in the ODD test area. The current results show that the critical depth of groundwater level affecting farmland secondary salinization is 4 m. In order to improve the salt discharge standard, SPD technology should be used on the basis of ODD. For salt that has accumulated in the soil for a long time, the technical mode of drip irrigation and leaching, followed by SPD drainage, in combination with the current irrigation system can achieve the goal of sustainable agriculture development.

Boosting lithium batteries under harsh operating conditions by a resilient ionogel with liquid-like ionic conductivity

New chemistries are being developed to increase the capacity and power of rechargeable batteries. However, the risk of safety issues increases when high-energy batteries using highly active materials encounter harsh operating conditions. Here we report on the synthesis of a unique ionogel electrolyte for abuse-tolerant lithium batteries. A hierarchically architected silica/polymer scaffold is designed and fabricated through a facile soft chemistry route, which is competent to confine ionic liquids with superior uptake ability (92.4 wt%). The monolithic ionogel exhibits high conductivity and thermal/mechanical stability, featuring high-temperature elastic modulus and dendrite-free lithium cycling. The Li/LiFePO4 pouch cells achieve outstanding cyclability at different temperatures up to 150 °C, and can sustain cutting, crumpling, and even coupled thermal–mechanical abuses. Moreover, the solid-state lithium batteries with LiNi0.60Co0.20Mn0.20O2, LiNi0.80Co0.15Al0.05O2, and Li1.2Mn0.54Ni0.13Co0.13O2 cathodes demonstrate excellent cycle performances at 60 °C. These results indicate that the resilient and high-conductivity ionogel electrolyte is promising to realize high-performance lithium batteries with high energy density and safety.

Nanostructured Polymer Composite Electrolytes with Self-Assembled Polyoxometalate Networks for Proton Conduction

Nanostructured Polymer Composite Electrolytes with Self-Assembled Polyoxometalate Networks for Proton Conduction

Nanoheterogeneity of LiTFSI Solutions Transitions Close to a Surface and with Concentration.

Water-in-salt (WIS) electrolytes composed of 21 m LiTFSI have recently emerged as a safe and environmentally friendly alternative to conventional organic electrolytes in Li-ion batteries. Several studies have emphasized the relation between the high conductivity of WIS electrolytes and their nanoscale structure. Combining force measurements with a surface forces apparatus and atomic force microscopy, this study describes the nanoheterogeneity of LiTFSI solutions as a function of concentration and distance from a negatively charged (mica) surface. We report various nanostructures coexisting in the WIS electrolyte, whose size increases with concentration and is influenced by the proximity of the mica surface. Two key concentration thresholds are identified, beyond which a transition of behavior is observed. The careful scrutinization on the concentration-dependent nanostructures lays groundwork for designing novel electrolytes in future energy storage devices.

Recent progress and future perspectives of flexible Zn-Air batteries

With the booming of flexible and wearable electronic devices, demands for compatible power supply devices with high energy density and safety, excellent flexibility for superior comfort, as well as compact structure to drive these wearable electronic devices are increased rapidly. Rechargeable solid-state flexible Zn-air battery (F-ZAB) is considered as one of the most competitive and promising energy storage system because of its high energy density, intrinsic safety, and flexible mechanical properties. In recent years, although cathode electrocatalysts have made great progress in improving the electrochemical properties of F-ZABs, the mechanical flexibility and durability of F-ZABs for wearable application still face many technical challenges. Moreover, with the miniaturization of wearable electronic devices, the on-chip integrability of F-ZABs is also needful. To maintain the balance among electrochemical properties, flexibility and integrability of F-ZABs, efficient catalyst, durable electrode, high conductivity and flexible electrolyte, and reasonable battery configuration are crucial. In this article, the latest advances and challenges of F-ZABs exploration are introduced though a detailed review of the battery components including the air electrode, Zn electrode, solid-state electrolyte, and the battery configuration. Meanwhile, challenges facing the development of F-ZABs are highlighted together with the discussion of further research directions and perspectives.

A flexible electron-blocking interfacial shield for dendrite-free solid lithium metal batteries

Solid-state batteries (SSBs) are considered to be the next-generation lithium-ion battery technology due to their enhanced energy density and safety. However, the high electronic conductivity of solid-state electrolytes (SSEs) leads to Li dendrite nucleation and proliferation. Uneven electric-field distribution resulting from poor interfacial contact can further promote dendritic deposition and lead to rapid short circuiting of SSBs. Herein, we propose a flexible electron-blocking interfacial shield (EBS) to protect garnet electrolytes from the electronic degradation. The EBS formed by an in-situ substitution reaction can not only increase lithiophilicity but also stabilize the Li volume change, maintaining the integrity of the interface during repeated cycling. Density functional theory calculations show a high electron-tunneling energy barrier from Li metal to the EBS, indicating an excellent capacity for electron-blocking. EBS protected cells exhibit an improved critical current density of 1.2 mA cm−2 and stable cycling for over 400 h at 1 mA cm−2 (1 mAh cm−2) at room temperature. These results demonstrate an effective strategy for the suppression of Li dendrites and present fresh insight into the rational design of the SSE and Li metal interface.

New insights into Li distribution in the superionic argyrodite Li6PS5Cl.

By using temperature-dependent neutron powder diffraction combined with maximum entropy method analysis, a previously unreported Li lattice site was discovered in the argyrodite Li6PS5Cl solid-state electrolyte. This new finding enables a more complete description of the Li diffusion model in argyrodites, providing structural guidance for designing novel high-conductivity solid-state electrolytes.