Potential For Energy Storage Systems Research Articles

Dual-regulation strategy to enhance electrochemical catalysis ability of NiCo2O4-x for polysulfides conversion in Li-S batteries

Recently, lithium-sulfur batteries (LSBs) have been considered as the most potential energy storage system, but the application of LSBs is still confronted with significant challenges. One among the significant challenges is the low kinetics. In this work, we design the urchin-like structure of NiCo2O4 to expose more catalytic sites to accelerate the lithium polysulfides (LiPSs) conversion. And the oxygen deficient in NiCo2O4 with spinel type structure (space group Fd3m) leads to the excellent chemical affinity of NiCo2O4-x for LiPSs. Moreover, because of the optimal distribution of electron on (311) plane of NiCo2O4-x, the Gibbs free energies of the evolution from S8 to Li2S on (311) plane of NiCo2O4-x is much lower than that of NiCo2O4, illustrating the NiCo2O4-x with the higher catalytic activity. Therefore, the cell with the NiCo2O4-x modified separator exhibits a superior rate performance (632 mAh g−1 at 2.5 C) and a long cycle life (404 mAh g−1 at 1 C after 800 cycles) with excellent Li+ ion diffusion coefficient. The rational structural optimization makes NiCo2O4-x become the efficient catalyst of LSBs. And the results promote the development of bimetallic oxides as catalyst in LSBs.

A Novel Sandwiched Porous MXene/Polyaniline Nanofibers Composite Film for High Capacitance Supercapacitor Electrode

AbstractAs a class of promising 2D material, MXenes are widely applied to energy storage systems (ESSs) due to metallic conductivity and high electrochemical activities, but the restacking problem during electrode preparation restricts their electrochemical performances. Herein, polyaniline nanofibers (PANINFs) are used as conductive interlayer spacers to induce the self‐assembly of MXene (Ti3C2Tx)‐based electrode. The favored sandwiched porous structure is formed due to the electrostatic adsorption and hydrogen bond interaction between the positively charged PANINFs and the negatively charged Ti3C2Tx nanosheets, which provide abundant accessible sites and facilitate the diffusion of ions. As a result, the flexible freestanding Ti3C2Tx/PANINFs composite electrode exhibits high conductivity (1373.3 S cm–1) and excellent gravimetric capacitance of 645.7 F g–1. Due to the enhanced structural stability, it achieves impressive cycling stability of 98% capacitance retention after 5000 cycles, which is significantly improved from that of pristine Ti3C2Tx electrode (84.6%). This work provides a feasible strategy for the structure regulation and performance enhancement of MXene‐based supercapacitors, which has great potential in energy storage systems.

Manipulating the ion-transference and deposition kinetics by regulating the surface chemistry of zinc metal anodes for rechargeable zinc-air batteries

Aqueous zinc-air battery (ZAB) has attractive features as the potential energy storage system such as high safety, low cost and good environmental compatibility. However, the issue of dendrite growth on zinc metal anodes has seriously hindered the development of ZAB. Herein, the N-doped carbon cloth (NC) prepared via magnetron sputtering is explored as the substrate to induce the uniform nucleation of zinc metal and suppress dendrite growth. Results show that the introduction of heteroatoms accelerates the migration and deposition kinetics of Zn2+ by boosting the desolvation process of Zn2+, eventually reducing the nucleation overpotential. Besides, theoretical calculation results confirm the zincophilicity of N-containing functional group (such as pyridine N and pyrrole N), which can guide the nucleation and growth of zinc uniformly on the electrode surface by both promoting the redistribution of Zn2+ in the vicinity of the surface and enhancing its interaction with zinc atoms. As a result, the half-cell assembled with magnetron sputtered carbon cloth achieves a high zinc stripping/plating coulombic efficiency of 98.8% and long-term stability of over 500 cycles at 0.2 mA cm−2. And the Coulombic efficiency reached about 99.5% at the 10th cycle and maintained for more than 210 cycles at a high current density of 5.0 mA cm−2. The assembled symmetrical battery can deliver 220 plating/stripping cycles with ultra-low voltage hysteresis of only 11 mV. In addition, the assembled zinc-air full battery with NC-Zn anode delivers a high special capacity of about 429 mAh gZn−1 and a long life of over 430 cycles. The effectiveness of surface functionalization in promoting the transfer and deposition kinetics of Zn2+ presented in this work shows enlightening significance in the development of metal anodes in aqueous electrolytes.

Economic Analysis of Centralized Energy Storage and Impact on NEM

Energy storage has a broad prospect in the future electricity market. Hornsdale Power Reserve (HPR), the largest battery energy storage system in Australia, was selected as the research case to evaluate the impact of energy storage systems on the National Electricity Market (NEM) operation and its economic benefits. The analysis of HPR includes its performance in the NEM and FCAS markets, its profitability, and its impact on the different markets, thus reflecting the feasibility and superiority of the energy storage system. The results show that energy storage is active in the FCAS market. By comparing the FCAS regulation performance of HPR and the conventional OCGT in South Australia and researching the response to sudden frequency changes, it is found that energy storage has accuracy, speed in regulating frequency, and maintaining system frequency stability. The economic analysis results show that the primary revenue of energy storage comes from the FCAS market. Taking HPR as an example, more than 70% of its electricity sales revenue comes from the FCAS market, especially the Contingency FCAS market. Comparing HPR with wind farms and PV farms of the same power size (100MW), its high IRR, short payback period, and relatively high NPV demonstrate the investment potential of energy storage systems. Optimizing HPR’s energy storage configuration achieves the maximum benefit when its scale expands by 50% (150MW). There will still be huge profits when grown by 100% (200MW), proving energy storage systems’ development potential. Using the economic sensitivity analysis of HPR to find ways to improve the energy storage system’s economic benefits, it can be seen that increasing the participation rate of the FCAS market and improving the technical level of the battery are the effective methods.

Freestanding Hierarchically Sandwich-Like TiS <sub>2</sub>-TiO <sub>2</sub>/MXene Film as Bi-Functional Interlayer for Stable Li-S Batteries

Lithium-sulfur battery (LSB) is considered a kind of potential energy storage systems on account of its high theoretical capacity (1675 mAh·g-1) and energy density (2500 Wh·Kg-1). However, poor ionic/electronic conductivity and annoying shuttle effects still need to be resolved. Here a highly flexible and highly conductive MXene (Ti3C2Tx) interlayer with a sandwich structure is reported, the surface of which is a TiS2/TiO2 heterostructure formed by vulcanized. In this framework, the role of TiO2 nanoparticles is adsorbent to combine the lithium polysulfides (LiPSs), and the TiS2 nanoparticles function as catalysts to further facilitate the conversion of long-chain LiPSs to short-chain Li2S2/Li2S under the high conductivity of Ti3C2Tx. Furthermore, the interlayer can protect the Lithium metal anode by preventing polysulfide from depositing on the anode surface. Accordingly, the TOS/MX/TOS interlayer exhibits excellent performance with stable long-term cycling (≈76.1% capacity retention with a decay rate of 0.048% per cycle after 500 cycles at 1C). This sandwiched interlayer with high discharge capacity and steady cycling performances is conducive to the practical application of lithium-sulfur batteries.

Synthesis and Electocatalytic Activity of MnO2/RuO2/Carbon Nanocomposites to Enhance Lithium-Oxygen Battery Performance

Lithium-oxygen battery has received much attention as a potential energy storage system because of its ultra-high theoretical energy density (5,200 Wh kg−1), which remains to be the most promising future technology. However, there are several scientific/technical hurdles that must be overcome in order for a rechargeable Li–air battery to be commercialized in the market. In particular, the incomplete decomposition of solid discharge products such as Li2O2 etc. formed during discharge process passivates the cathode surface by clogging pores of the porous carbon cathode, resulting in diminishing the overall performance of battery. In order to solve these issues, great effort has been devoted to designing and developing novel electrocatalysts. It has been reported that electrocatalysts play an important role in ORR and OER, and hence improve the kinetics and efficiency of the Li–air battery.In this work, a suitable bifunctional catalyst was synthesized with MnO2 and RuO2, which are the well-known catalysts for oxygen reduction reaction(ORR) and oxygen evolution reaction(OER), respectively, by supporting on two different carbon supports such as graphite nanofiber(GNF) and graphene oxide(GO) for the application to oxygen cathode bifunctional catalysts of lithium-air batteries. MnO2/GNF was first prepared by a simple hydrothermal synthesis and was then decorated with various decorating ratios of RuO2 using a simple redox reaction technique. A good electrocatalytic performance was observed from a weight ratio of RuO2:MnO2/GNF=5:5. The Li-oxygen battery fabricated with the synthesized catalyst composition delivered a reduced overpotential with good cyclability and high specific capacity. In order to understand the effect of carbon, urchin-shaped α-MnO2/RuO2 nanostructures was first synthesized by a hydrothermal synthesis and was then loaded on GO with a weight ratio of 5:5 using a redox reaction technique. The synthesized α-MnO2/RuO2@GO (5:5) composite delivered high specific capacity with excellent electrocatalytic activity. Between the two different carbon supported composites, RuO2@MnO2/GNF showed excellent catalytic activity than α-MnO2/RuO2@GO. The increase in the surface area of carbon supports greatly influenced the performance of Li-air battery. Catalysts with carbon supports showed higher activity than without carbon. RuO2@MnO2/GNF was found to be the best catalyst which has two or tree times larger surface area than α-MnO2/RuO2@GO. Thus, RuO2@MnO2/GNF with 5:5 weight percentage was found to be the best electrocatalyst than all other synthesized catalysts.

Unraveling the Effect of Singlet Oxygen on Metal-O2 Batteries: Strategies Toward Deactivation.

Aprotic metal-O2 batteries have attracted the interest of the research community due to their high theoretical energy density that target them as potential energy storage systems for automotive applications. At present, these devices show various practical problems, which hinder the attainment of the high theoretical energy densities. Among the main limitations, we can highlight the irreversible parasitic reactions that lead to premature death of the battery. The degradation processes, mainly related to the electrolyte, lead to the formation of secondary products that accumulate throughout the cycling in the air electrode. This accumulation of predominantly insulating products results in the blocking of active sites, promoting less efficiency in system performance. Recently, it has been discovered that the superoxide intermediate radical anion is involved in the generation of the reactive oxygen singlet species (1O2) in metal-O2 batteries. The presence of singlet oxygen is intimately linked with electrolyte degradation processes and with carbon-electrode corrosion reactions. This review analyzes the nature of singlet oxygen, while clarifying its toxic role in metal-O2 batteries. Besides, the main mechanisms of deactivation of singlet oxygen are presented, trying to inspire the research community in the development of new molecules capable of mitigating the harmful effects related to this highly reactive species.

Intercalation of Mg into a Few-Layer Phyllomanganate in Nonaqueous Electrolytes at Room Temperature

The use of oxide cathodes in Mg batteries would unlock a potential energy storage system that delivers high energy density. However, poor kinetics of Mg diffusion in known solid oxide lattices stro...

A Long-Cycling Aqueous Zinc-Ion Pouch Cell: NASICON-Type Material and Surface Modification.

Aqueous zinc-ion batteries (ZIBs) have become the highest potential energy storage system for large-scale applications owing to the high specific capacity, good safety and low cost. In this work, a NASICON-type Na3 V2 (PO4 )3 cathode modified by a uniform carbon layer (NVP/C) has been synthesized via a facile solid-state method and exhibited significantly improved electrochemical performance when working in an aqueous ZIB. Specifically, the NVP/C cathode shows an excellent rate capacity (e. g., 48 mAh g-1 at 1.0 A g-1 ). Good cycle stability is also achieved (e. g., showing a capacity retention of 88% after 2000 cycles at 1.0 A g-1 ). Furthermore, the Zn2+ (de)intercalation mechanism in the NVP cathode has been determined by various ex-situ techniques. In addition, a Zn||NVP/C pouch cell has been assembled, delivering a high capacity of 89 mAhg-1 at 0.2 A g-1 and exhibiting a superior long cycling stability.

Realizing a Rechargeable High‐Performance Cu–Zn Battery by Adjusting the Solubility of Cu2+

AbstractRechargeable aqueous Zn‐based batteries show great potential for energy storage systems due to their good reliability, low cost, environmental friendliness, etc. However, the capacity of the most studied Mn‐, V‐, and Prussian blue analog‐based Zn‐ion batteries (the type with Zn2+ insertion) and the other type Zn‐based batteries without Zn2+ insertion (such as metal Ag and Ni or Co oxides/hydroxides) does not exceed 400 mAh g−1. Cu is a promising cathode with a high theoretical capacity of 844 mAh g−1 based on its unique two‐electron transfer process (Cu0 ↔ Cu2+), but Cu–Zn batteries have been impractical to recharge since they was invented by Daniell in 1836. By adjusting the solubility of Cu2+ in an alkaline solution, a rechargeable high‐performance Cu–Zn battery is achieved. A high specific capacity of 718 mAh g−1 is obtained for the prepared Cu clusters. Moreover, commercial Cu foil is explored for direct use as the cathode material and shows high capacity and stability through a simple self‐activation process. This rechargeable Cu–Zn battery is attractive for application due to its high capacity, simple synthesis method, environmental friendliness, and low cost.

Graphite carbon-encapsulated metal nanoparticles derived from Prussian blue analogs growing on natural loofa as cathode materials for rechargeable aluminum-ion batteries

Aluminum-ion batteries (AIBs) are attracting increasing attention as a potential energy storage system owing to the abundance of Al sources and high charge density of Al3+. However, suitable cathode materials to further advance high-performing AIBs are unavailable. Therefore, we demonstrated the compatibility of elemental metal nanoparticles (NPs) as cathode materials for AIBs. Three types of metal NPs (Co@C, Fe@C, CoFe@C) were formed by in-situ growing Prussian blue analogs (PBAs, Co[Co(CN)6], Fe[Fe(CN)6] and Co[Fe(CN)6]) on a natural loofa (L) by a room-temperature wet chemical method in aqueous bath, followed by a carbonization process. The employed L effectively formed graphite C-encapsulated metal NPs after heat treatment. The discharge capacity of CoFe@C was superior (372 mAh g−1) than others (103 mAh g−1 for Co@C and 75 mAh g−1 for Fe@C). The novel design results in CoFe@C with an outstanding long-term charge/discharge cycling performance (over 1,000 cycles) with a Coulombic efficiency of 94.1%. Ex-situ X-ray diffraction study indicates these metal NP capacities are achieved through a solid-state diffusion-limited Al storage process. This novel design for cathode materials is highly significant for the further development of advanced AIBs in the future.

Pre-lithiated carbon-coated Si/SiOx nanospheres as a negative electrode material for advanced lithium ion capacitors

A high-performance lithium ion capacitor (LIC) composed of activated carbon (as the positive electrode) and pre-lithiated C-coated Si/SiOx nanospheres (as the negative electrode) is investigated as a potential energy storage system for high-power and high-energy applications. Under optimized pre-lithiation conditions, the feasibility of pre-lithiated C-coated Si/SiOx nanospheres is thoroughly examined as an advanced negative electrode compared with a conventional graphite LIC using pre-lithiated C-coated Si/SiOx nanospheres. The pre-lithiated C-coated Si/SiOx nanospheres show much improved reversible capacity and rate capability with higher capacity retention at a high current density of 10C up to 1000 cycles compared with a conventional LIC. Such improvements may be attributed to the unique physical and chemical properties of C-coated Si/SiOx nanospheres. We believe that this approach provides a practical guideline for developing and successfully implementing advanced LICs.

A High Capacity Aluminum‐Ion Battery Based on Imidazole Hydrochloride Electrolyte

AbstractAluminum‐ion batteries (Al‐ion batteries) have become a potential energy storage system, owing to their excellent cycling performance, three‐electron‐redox properties, and safety performance. Until now, great progress has been made in Al‐ion batteries. However, the Al‐ion battery system still encounters various problems, such as high electrolyte price, harsh working environment, low discharge platforms, and inferior capacity. Here, we prepared a novel Al‐ion battery with AlCl3/Imidazole hydrochloride (ImidazoleHCl) as the electrolyte, aluminum as the negative electrode, and commercial graphite as the positive electrode. The battery achieves a high specific discharge capacity of 129 mA h g−1 at a current density of 0.5 A g−1 and 105 mA h g−1 with a high coulombic efficiency of 99 % at the current density of 4 A g−1 after 1000 cycles. The mechanism of AlCl4− intercalation/de‐intercalation is proved by Raman, XRD and EDS studies. ImidazoleHCl is a promising electrolyte and this work provides a new insight for the Al‐ion battery system.

A magnetic self-contained thermochromic system with convenient temperature range

A sugar-based ionic liquid ligand coordinated to cobalt(ii) exhibits magnetic switching and marked thermochromism in spectator ionic liquid solution/polymer films over a convenient temperature range (20–60 °C), resulting in a potential energy storage system.

Finely Crafted 3D Electrodes for Dendrite‐Free and High‐Performance Flexible Fiber‐Shaped Zn–Co Batteries

AbstractRechargeable aqueous Zn‐based batteries, benefiting from their good reliability, low cost, high energy/power densities, and ecofriendliness, show great potential in energy storage systems. However, the poor cycling performance due to the formation of Zn dendrites greatly hinders their practical applications. In this work, a trilayer 3D CC‐ZnO@C‐Zn anode is obtained by in situ growing ZIFs (zeolitic‐imidazolate frameworks) derived ZnO@C core–shell nanorods on carbon cloth followed by Zn deposition, which exhibits excellent antidendrite performance. Using CC‐ZnO@C‐Zn as the anode and a branch‐like Co(CO3)0.5(OH)x·0.11H2O@CoMoO4 (CC‐CCH@CMO) as the cathode, a Zn–Co battery is rationally designed, displaying excellent energy/power densities (235 Wh kg−1, 12.6 kW kg−1) and remarkable cycling performance (71.1% after 5000 cycles). Impressively, when using a gel electrolyte, a highly customizable, fiber‐shaped flexible all‐solid‐state Zn–Co battery is assembled for the first time, which presents a high energy density of 4.6 mWh cm−3, peak power density of 0.42 W cm−3, and long durability (82% capacity retention after 1600 cycles) as well as excellent flexibility. The unique 3D electrode design in this study provides a novel approach to achieve high‐performance Zn‐based batteries, showing promising applications in flexible and portable energy‐storage systems.

Nitrogen doped carbon derived from polyimide/multiwall carbon nanotube composites for high performance flexible all-solid-state supercapacitors

Flexible all-solid-state supercapacitors are desirable as potential energy storage systems for wearable technologies. Herein, we synthesize aminophenyl multiwall carbon nanotube (AP-MWCNT) grafted polyimide precursor by in situ polymerization method as a nitrogen-doped carbon precursor. Flexible supercapacitor electrodes are fabricated via a coating of carbon precursor on carbon cloth surface and carbonization at high temperature directly. The as-obtained electrodes, which can be directly used without any binders or additives, can deliver a high specific capacitance of 333.4 F g−1 at 1 A g−1 (based on active material mass) and excellent cycle stability with 103% capacitance retention after 10,000 cycles in a three-electrode system. The flexible all-solid-state supercapacitor device exhibits a high volumetric capacitance of 3.88 F cm−3 at a current density of 0.02 mA cm−3. And also the device can deliver a maximum volumetric energy density of 0.50 mWh cm−3 and presents good cycling stability with 85.3% capacitance retention after 10,000 cycles. This device cell can not only show extraordinary mechanical flexibilities allowing folding, twisting, and rolling but also demonstrate remarkable stable electrochemical performances under their forms. This work provides a novel approach to obtain carbon textile-based flexible supercapacitors with high electrochemical performance and mechanical flexibility.

Communication—Direct Observation of the Shuttle Phenomenon in Lithium-Sulfur Batteries via the Digital Holographic Method

Lithium-sulfur (Li-S) batteries are regarded as the best potential-energy storage systems because of their ultra-high energy density. However, their electrochemical performance is limited by the well-known shuttle effect. We used an online digital holography method to investigate the interfacial changes between the electrode and the electrolyte. An in-situ observation of the shuttle process was achieved in Li-S batteries. This result confirms the existence of the shuttle mechanism, and aids in the selection of preferable composite cathodes and electrolytes to produce high-performance Li-S batteries.

Magnesium stannide as a high-capacity anode for magnesium-ion batteries

Driven by the limited global resources of lithium, magnesium metal batteries are considered as potential energy storage systems. The battery chemistry of magnesium metal anode, however, limits the selection of electrolytes, cathode materials and working temperature, making the realization of magnesium metal batteries complicated. Herein, we report the development of a new magnesium-insertion anode, magnesium stannide (Mg2Sn), and demonstrate reversible electrochemical Mg2+-extraction and insertion of Mg2Sn anode at 0.2 V versus Mg, delivering discharge capacity of 270 mAhg−1 in a half-cell with the electrolyte of PhMgCl/THF and enabling of room temperature magnesium-ion batteries with Mg2Sn anode combined with Mg-free oxide cathode and conventional-type electrolyte of Mg(TFSI)2/diglyme. The combination of Mg2Sn anode with various cathodes and electrolytes holds great promise for enabling room temperature magnesium-ion batteries.

A Design of Solid-State Li-S Cell with Evaporated Lithium Anode To Eliminate Shuttle Effects.

Li-S batteries hold great potential for energy storage systems due to their high theoretical capacity and low cost. However, the shuttle of polysulfides in conventional Li-S batteries with organic electrolyte results in severe problems, such as low Coulombic efficiency and poor cycling stability. Here, we developed a solid-state Li-S battery using Li1.5Al0.5Ge1.5(PO4)3 (LAGP) solid ceramic electrolyte instead of liquid electrolyte. Lithium film was deposited on one side of LAGP by an evaporation method to improve the contact between anode and LAGP. Sulfur-coated carbon nanotubes cathode (S-MWCNT) composition was casted on the other side of LAGP as the cathode and a small amount of ionic liquid was dropped in order to improve the ionic conductivity. This battery exhibited a high capacity of 1510 mAh g-1 in the first cycle and retained 1400 mAh g-1 after 30 cycles. Meanwhile, the Coulombic efficiency of the battery was almost 100% for each cycle, which indicated the shuttle effect was circumvented completely.

P and Si functionalized MXenes for metal-ion battery applications

MXenes are a family of two-dimensional materials, composed of early transition metal carbides, nitrides, and carbonitrides, with great potential in energy storage systems, in particular in electrodes for Li, Na, K-ion batteries. However, so far the capacities are not competitive. In this context, we investigate P and Si functionalized MXenes for metal-ion battery applications, using first-principles calculations, since P and Si provide reaction products with high ion content. Replacement of the F and OH ligands of Ti2C and V2C with P and Si is demonstrated to be feasible (energy barriers of less than 0.128 eV) and the ion diffusion barriers turn out to be less than 0.32 eV. Importantly, the Li, Na, and K capacities are predicted to be 1767 mAh g−1, 711 mAh g−1, and 711 mAh g−1, respectively, thus being much higher than in the case of F and OH functionalization.