High Cycling Performance Research Articles

Sb/SnO@C composite prepared by electrospinning for high performance sodium ion battery anodes

The development of high-performance anode material for sodium-ion batteries remains a challenge because of their low capacity, which limits their commercial application. Compared with carbon-based materials, metallic Sb and SnO-based anodes have received extensive attention because of their high theoretical specific capacity and safe working potential. The main problem faced is the serious volume expansion during charging and discharging, leading to irreversible loss of capacity and poor cycle life. In this paper, Sb/SnO@C composite material with adjustable ratio of Sb/SnO was prepared via electrospinning by encapsulating Sb and SnO particles in lantern-like carbon nanocages which connected through the nanofibers. The unique structure can not only effectively mitigate the volume changes during the cycle, but also provide multiple effective paths for ion and electron transport. The kinetic analysis is further performed with the assist of CV and EIS. The results show that the prepared composite can provide impressive Na+ ions storage and transport performance, and can still deliver a reversible charging capacity of 413mAhg−1 after 200 cycles at a current density of 50mAg−1, with a capacity retention ratio of 84%. This work provides a new strategy for the development of sodium ion batteries with high capacity and stable cycle performance.

Synergistic ion transport facilitated by one-dimension wollastonite in solid polymer electrolytes for stable lithium metal batteries

Solid polymer electrolytes suffer from relatively low Li+ conductivity, poor mechanical strength and interfacial incompatibility with electrodes, which hinder their further application in solid-state batteries. In this work, one-dimension (1D) wollastonite fillers are introduced into the solid polymer electrolyte, which not only contribute to the improved mechanical strength and electrochemical window, but also effectively inhibit polymer crystallization. More importantly, the abundant Lewis sites at wollastonite surface provide 1D ion pathway to boost ion transport in the electrolyte, achieving high ionic conductivity and Li+ transfer number. Owing to these favorable properties, the as-prepared polymer electrolyte exhibits enhanced interfacial stability toward Li anode, enabling long-term cycling in a Li-Li symmetric cell without short circuit. Showing good interfacial compatibility with both LiFePO4 and LiCoO2 cathode materials, the modified polymer electrolyte delivers high rate capability (143 mAh g−1 at 5C) and stable cycling performance (capacity retention of 93.12% after 380 cycles) in full cells. Through regulating the interfacial interactions between polymer matrix and fillers, this work points out a new direction towards high-performance all-solid-state batteries.

One-Dimensional Croconate-Based Fe-CP as a High-Performance Anode Material for Lithium-Ion Batteries.

Coordination polymers (CPs) have attracted greater scientific attention as promising electrode materials for lithium-ion batteries (LIBs) due to their diverse and versatile structural chemistry. This study introduces a croconate-based one-dimensional CP, namely [Fe(C5O5)(H2O)3]n) (referred to as Fe-CP), as an efficient anode material with high-performance characteristics for rechargeable LIBs. The ligand with abundant redox sites coordinating to the transition metal ion endowed the anode material with a remarkable stability in the electrolyte, in addition to high capacity, high-rate capability, and high cycling performance during charging/discharging process. The Fe-CP has a unique chain-based supramolecular structure, setting it apart from other porous three-dimensional molecular materials. The presence of unrestricted channels between the chains facilitates the diffusion of lithium ions in this unique structure. When tested at 100 mA g-1 over a range of voltages between 0.01 and 2.4 V, the Fe-CP anode demonstrated a noteworthy specific capacity of 521 mA h g-1 over 140 cycles. Moreover, the Fe-CP anode material exhibited excellent rate performance and demonstrated favorable cyclability. Following exposure to high charging and discharging rates of 2 A g-1, the anode ultimately regained its initial capability when the current rate was back at 100 mA g-1.

Anti-Shedding Nickel-Protection-Layer Boosting an Ultrahigh Loading Carbon Fiber@Co-NiSx Electrode to Deliver Superior Areal/Volumetric/Gravimetric Capacitance.

Challenges remain to show good capacitive performance while achieving high loadings of active materials for supercapacitors. Trying to realize this version, a nickel-protecting carbon fiber paper@Co-doped NiSx (Ni-CP@Co-NiSx) electrode with high specific gravimetric, areal, and volumetric capacitance is reported in this work. This free-standing electrode is prepared by an electroplating-hydrothermal-electroplating (EHE) three-step method to achieve a high loading of almost 26.7 mg cm-2. The cobalt-doping and nickel-protection strategies effectively decrease the impedance and inhibit the active material dropping from the electrode resulting from the expansion stress, which endows the Ni-CP@Co-NiSx electrode with a high rate and good cycling performance, especially with an ultrahigh specific areal/volumetric/gravimetric capacitance of 53.3 F cm-2/2807 F cm-3/1997 F g-1 at 5 mA cm-2, respectively. Employing activated carbon functionalized with riboflavin (AC/VB2) as a negative electrode, the asymmetric supercapacitor device delivers a very high energy density of up to 60.4 W h kg-1. This work demonstrates that electrodes with a high loading density and excellent performance can be obtained by the combination of the EHE method to adjust the internal conductivity and external structural stability.

Achieving stable interphases toward lithium metal batteries by a dilute and anion-rich electrolyte

It is necessary to find an ideal electrolyte suitable for high performance lithium metal batteries (LMBs). Herein, we construct a novel cluster-like and anion-rich dilute electrolyte system by using LiNO3 and trace lithium trifluoromethanesulfonate (LiOTf) in an ester-based electrolyte. In the designed system, NO3– is used as a modulator to regulate the coordination number of solvents and anions, and LiOTf is applied as a solubilizing agent of LiNO3 and trigger for the generation of large cluster. As a result, an anion-regulated solvation structure (ARSS) is obtained even in a dilute Li-ion concentration (<1.5 M), evidenced by various techniques, enabling the electrolyte a high ion-conductivity which vastly differs from a high concentration electrolyte system. Afterwards, the ARSS facilitates the formation of an inorganic-rich solid electrolyte interface (SEI) on both cathode and anode, ensuring the LMBs high stability and long cycling performance.

Hemimorphite /C interface layer with dual-effect methodically redistricted Zn2+ deposition behavior for dendrite-free zinc metal anodes

The uneven distribution of Zn2+ gradient and electric fields at the electrolyte–anode interface are the two “pain points” that seriously limit the lifespan of AZIBs. Traditional artificial SEI layers targeted one single “pain points” cannot simultaneously balance the Zn2+ gradient and electric fields. Herein, hemimorphite/C interface layer, sandwich structure Zn4(Si2O7)(OH)2·H2O@rGO@Zn4(Si2O7)(OH)2·H2O (rGO@ZnSi) prepared by in-situ growth strategy is provided as “dual-effect” to modulate Zn2+ gradient and electric fields regulation. The rGO@ZnSi is demonstrated with the zincophilicity due to Zn-ion-conducive transport channel about 5Å and boosted electroconductibility properties by in situ growth rGO. The internal rGO acts as conductive core, facilitating the rapid transfer of electrons along the two-dimensional plane, thus significantly enhancing the conductivity of hemimorphite. Additionally, it opens up a new territory for Zn2+ reduction process, which would enhance the reversibility of Zn anode, mitigate the polarization and promote electrochemical performance. The Zn//Zn battery with the modified rGO@ZnSi SEI exhibits an ultra-long and outstanding cycling stability of up to 170 days. Benefitting from the rGO@ZnSi SEI, the rGO@ZnSi-Zn//V2O5 full battery delivers a high discharge capacity and long cycle performance. The “dual-effect” rGO@ZnSi SEI escorts for the dendrite-free zinc metal anodes with lifetime extension, ultra-high rate performance and cost-effectiveness.

Carbon‐Binder Design for Robust Electrode–Electrolyte Interfaces to Enable High‐Performance Microsized‐Silicon Anode for Batteries

AbstractMicrosized‐silicon (µ‐Si, &gt;1 µm) is one of the ideal anodes for lithium‐ion batteries due to its low‐cost, high tap density, and high specific capacity. However, during repeated lithiation/delithiation processes, µ‐Si undergoes huge volume changes. This leads to continued capacity loss during cycling due to severe particle pulverization, separation from the conductive network and uncontrolled growth of an unstable solid‐electrolyte interphase (SEI). Herein, an electrode construction strategy is proposed by carbonization of the slurry‐casting µ‐Si electrode. The organic binder serves as both carbon resource and physical framework, which is carbonized to form a carbon binder that is chemically bonded with the µ‐Si particles and within the electrode. The electrode with carbon binder ensures stable electric channel and promotes formation of a stable and passivating SEI at the interface with a high µ‐Si content up to 82 wt%. The carbon binder offers physical buffer that shield against localized strain and modifies the surface reactivity, which enables a high initial Coulombic efficiency (91.85%) and stable cycle performance at commercial‐level areal capacities (2 mAh cm−2). This work offers an easily scalable yet practical approach for the current battery industry without any electrolyte modification or complicated manufacturing methods.

Physical vapor deposition of Sb2Se3 films as high-performance anode materials in quasi-solid-state Li-ion batteries

Antimony selenide (Sb2Se3) thin films with cluster morphology were prepared using physical vapor deposition method combined with the post-annealing process. The composition and morphology of the prepared films were characterized by X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. Electrochemical analysis of the samples revealed that the Li/Sb2Se3 half-cell exhibited an initial discharge specific capacity of 825.7 mAh∙g−1 at a current density of 0.5 C, and a discharge specific capacity of 1192.7 mAh∙g−1 after 100 charge-discharge cycles. The Sb2Se3 film also displayed excellent rate characteristics and a high cycling performance with a high discharge specific capacity of 812.2 mAh∙g−1 at current density of 2 C after 600 charge-discharge cycles. Results obtained from the galvanostatic intermittent titration tests and from electrochemical impedance spectroscopy proved that the cluster structure of the thin film was beneficial to the ion transport characteristics, as well as for the rate performance of the Sb2Se3 thin film materials. A quasi-solid-state battery based on Sb2Se3/Li1.3Al0.3Ti1.7(PO4)3/LiFePO4 was also assembled, which provided a discharge specific capacity of 445.5 mAh∙g−1 at 0.5 C with a capacity retention rate of 49.7% after 200 charge-discharge cycles. The results of this study clearly suggest that the use of Sb2Se3 films as anode materials can provide promising results in the performance enhancement of quasi-solid-state Li-ion batteries.

Facile Constructing Hierarchical Fe3O4@C Nanocomposites as Anode for Superior Lithium-Ion Storage

Ferroferric oxide (Fe3O4) is regarded to be a promising high-capacity anode material for LIBs. However, the capacity attenuates fast and the rate performance is poor due to the dramatic pulverization and sluggish charge transfer properties. To solve these problems, a simple in situ encapsulation and composite method was successfully developed to construct carbon nanotube/nanorod/nanosheet-supported Fe3O4 nanoparticles. Owing to the hierarchical architecture design, the novel structure Fe3O4@C nanocomposites effectively enhance the charge transfer, alleviate pulverization, avoid the agglomeration of Fe3O4 nanoparticles, and also provide superior kinetics toward lithium storage, thereby showing significantly improved reversibility and rate performance. The carbon nanotube/nanorod supported core-shell structure Fe3O4@C nanocomposite displays outstanding high rate capability and stable cycling performance (reversible capability of 1006, 552 and 423 mA h g−1 at 0.2, 0.5 and 1 A g−1 after running 100, 300 and 500 cycles, respectively).

4V-class Magnesium-ion pseudocapacitors fabricated using an in situ inverse-charging process

Pseudocapacitors can deliver much more improved energy densities than those (<4% of typical lithium-ion batteries) of the electrochemical double layer (EDL) capacitors. Nevertheless, surface-limited redox behaviors based on typical monovalent-ion charge carriers exhibit insufficient energy densities, necessitating a new high-performance electrochemical system based on a feasible cell configuration. In this study, 4 V-class multivalent magnesium-ion pseudocapacitors (MIPs) were fabricated from mass-producible nanocarbon electrodes and a glyme-based electrolyte system via an in situ electrochemical oxidation process. A redox-free nanocarbon electrode was electrochemically tuned into a pseudocapacitive nanocarbon anode (PNA) using a well-controlled oxidation process, showing an approximately four times higher specific capacitance value (∼196F g−1) compared with its initial EDL capacitance. The dual experimental and theoretical analysis results elucidate that the pseudocapacitance originates from the strong chemisorption ability with divalent magnesium-ions by the concerted effect of surface carbonyl functional groups and topological carbon defects. The high-capacitance PNA can work in a wide voltage range of 4 V. Therefore, the PNA-based MIP showed a high specific energy density of 167 Wh kg−1, which is much higher than those (46 ∼ 145 Wh kg−1) of previously reported alkali-ion capacitors. Additionally, a high cycling performance of the MIP full cell was achieved over 5,000 cycles.

Modification of carbon felt electrode by MnO@C from metal-organic framework for vanadium flow battery

The electrode, where electrochemical reactions are taken place, plays a vital role in the overall performance of vanadium flow batteries (VFBs). In this paper, a composite of manganese oxide and amorphous carbon was first synthesized from metal-organic frameworks and used as a catalyst to promote the electrochemical behavior of electrodes. The newly proposed catalyst was fabricated by a carbonization process of Mn-based metal-organic framework obtained by hydrothermal method. The morphology, composition, electrochemical activity and cell performance are respectively studied. The results show that: i) the catalyst carbonized at 900 °C possesses a smaller size, larger specific surface area, more oxygen-containing functional group and realizes superior electrochemical activity; ii) it helps the vanadium flow battery to increase its energy efficiency by 6% at 100 mA cm−2; iii) it is also beneficial to the working voltage, discharge capacity, high current density property and cycling performance of VFBs. Thus, this work can not only provide a new type of electrochemical catalyst for vanadium flow batteries, but also be significant to the improvement of the overall performance and conducive to the widespread application of vanadium flow batteries.

Co-Solvent Electrolyte Design to Inhibit Phase Transition toward High Performance K+/Zn2+ Hybrid Battery.

Manganese hexacyanoferrate (MnHCF) is one of the most promising cathode materials for aqueous battery because of its non-toxicity, high energy density, and low cost. But the phase transition from MnHCF to Zinc hexacyanoferrate (ZnHCF) and the larger Stokes radius of Zn2+ cause rapid capacity decay and poor rate performance in aqueous Zn battery. Hence, to overcome this challenge, a solvation structure of propylene carbonate (PC)-trifluoromethanesulfonate (Otf)-H2O is designed and constructed. A K+/Zn2+ hybrid battery is prepared using MnHCF as cathode, zinc metal as anode, KOTf/Zn(OTf)2 as the electrolyte, and PC as the co-solvent. It is revealed that the addition of PC inhabits the phase transition from MnHCF to ZnHCF, broaden the electrochemical stability window, and inhibits the dendrite growth of zinc metal. Hence, the MnHCF/Zn hybrid co-solvent battery exhibits a reversible capacity of 118mAhg-1 and high cycling performance, with a capacity retention of 65.6% after 1000 cycles with condition of 1Ag-1. This work highlights the significance of rationally designing the solvation structure of the electrolyte and promotes the development of high-energy-density of aqueous hybrid ion batteries.

Applications and Challenges of Lithium-Sulfur Electrochemical Batteries

&lt;p&gt;This paper presents applications of lithium-sulfur (Li-S) energy storage batteries, while showing merits and demerits of several techniques to mitigate their electrochemical challenges. Unmanned aerial vehicles, electric cars, and grid-scale energy storage systems represent main applications of Li-S batteries due to their low cost, high specific capacity, and light weight. However, polysulfide shuttle effects, low conductivities, and low coulombic efficiencies signify key challenges of Li-S batteries, causing high volumetric changes, dendritic growths, and limited cycling performances. Solid-state electrolytes, interfacial interlayers, and electrocatalysts denote promising methods to mitigate such challenges. Moreover, nanomaterials have capability to improve kinetic reactions of Li-S batteries based on several properties of nanoparticles to immobilize sulfur in cathodes, stabilizing lithium in anodes while controlling volumetric growths. Li-S energy storage technologies are able to satisfy requirements of future markets for advanced rechargeable batteries with high-power densities and low costs, considering environmentally friendly systems based on renewable energy sources.&lt;/p&gt;

Polyaniline-MXene composite electrode with excellent electrochemical properties for all-solid flexible supercapacitors

In this paper, MXene based electrode active materials and MXene cross-linked polyacrylic acid hydrogel electrolytes with high cycling performance and high specific capacitance have been successfully prepared. Polyaniline with high capacitance values has been grown on the MXene surface by in situ polymerization, which can significantly improve electrochemical properties. As the MXene surface is rich in functional groups, it can be used as a nucleation site for in situ polymerization of aniline monomers deposited. The PANI filled with MXene forms a 3D porous conductive network reducing the self-stacking of MXene and providing a large number of channels for electrolyte ions to enter MXene. The supercapacitor has been tested and assembled with good flexibility and the specific capacitance has risen to 222 F g−1. The capacitance retention of 98.5 % after 10,000 charges and discharges is due to the improved performance of the composite material and the excellent stability of the gel electrolyte and electrodes. The above results show that the prepared electrodes and devices have promising applications in flexible wearable devices.

Shape-Controlled First-Row Transition Metal Vanadates for Electrochemical and Photoelectrochemical Water Splitting.

Transition metal vanadates (MVs) possess abundant electroactive sites, short ion diffusion pathways, and optical properties that make them suitable for various electrochemical (EC) and photoelectrochemical (PEC) applications. While these materials are commonly used in energy storage devices like batteries and capacitors, their shape-controlled 1D and 2D morphologies have gained equal popularity in water splitting (WS) technology in recent times. This review focuses on recent progress made on various first-row (3d, 4 s) transition metal vanadates (t-MVs) having controlled one-dimensional (fiber, wire, or rod) and two-dimensional (layered or sheet) morphologies with a specific emphasis on copper vanadates (CuV), cobalt vanadates (CoV), iron vanadates (FeV), and nickel vanadates (NiV). The review covers different aspects of shape-controlled 1D and 2D t-MVs including optoelectrical properties, wet chemistry synthesis, and electrochemical (EC-WS) and photoelectrochemical water splitting (PEC-WS) performance in terms of onset potential, overpotential, and long-term stability or high cyclic performance. The review concludes by providing some possible thoughts on how to promote the water-splitting attributes of shape-controlled t-MVs more effectively.

Synergistically boosting reaction kinetics and suppressing polyselenide shuttle effect by Ti3C2Tx/Sb2Se3 film anode in high-performance sodium-ion batteries

Antimony selenide (Sb2Se3), with rich resources and high electrochemical activity, including in conversion and alloying reactions, has been regarded as an ideal candidate anode material for sodium-ion batteries. However, the severe volume expansion, sluggish kinetics, and polyselenide shuttle of the Sb2Se3-based anode lead to serious pulverization at high current density, restricting its industrialization. Herein, a unique structure of Sb2Se3 nanowires uniformly anchored between Ti3C2Tx (MXene) nanosheets was prepared by the electrostatic self-assembly method. The MXene can impede the volume expansion of Sb2Se3 nanowires in the sodiation process. Moreover, the Sb2Se3 nanowires can reduce the restacking of Ti3C2Tx nanosheets and enhance electrolyte accessibility. Furthermore, density functional theory calculations confirm the increased reaction kinetics and better sodium storage capability through the composite of Ti3C2Tx with Sb2Se3 and the high adsorption capability of Ti3C2Tx to polyselenides. Therefore, the resultant Sb2Se3/Ti3C2Tx anodes show high rate capability (369.4 mAh/g at 5 A/g) and cycling performance (568.9 and 304.1 mAh/g at 0.1 A/g after 100 cycles and at 1.0 A/g after 500 cycles). More importantly, the full sodium-ion batteries using the Sb2Se3/Ti3C2Tx anode and Na3V2(PO4)3/carbon cathode exhibit high energy/power densities and outstanding cycle performance.

Iron MOF-Derived Fe2O3/NPC Decorated on MIL-88A Converted Fe3C Implanted Electrospun Porous Carbon Nanofibers for Symmetric Supercapacitors

Moderated thermal transformation of metal–organic frameworks (MOFs) empowers the synthesis of nanomaterials with precisely controlled porosities and morphologies, leading to enhanced performance in energy storage applications. Herein, we prepared MIL-88A-derived Fe3C-integrated EPCNFs (EPCNFs = electrospun porous carbon nanofibers) mats for the outside growth of Fe-MOFs using a moderated temperature calcination technique. The applied technique endorsed the conversion of the Fe-MOFs into Fe2O3/NPC (NPC = nanoporous carbon) without any destruction in the morphology of the nanorods. The integrated MIL-88A-derived Fe3C reduces the intrinsic resistance and synergizes with the overall performance of the resulting negative electrode (Fe2O3/NPC@Fe3C/EPCNFs). The resulting MOF-derived electrode materials have excellent performance within the −1 to 0 window potential range. The optimized electrode Fe2O3/NPC-350@Fe3C/EPCNFs exhibits a high specific capacitance (531 F g–1 at 1 A g–1) and stable cycling performance, retaining more than 90% even after 20000 cycles. The uniform, vertical, porous, and highly interconnected tetragonal rod-like nanomaterials can also maintain structural integrity during continuous charge/discharge. In addition, the assembled symmetric supercapacitor (Fe2O3/NPC-350@Fe3C/EPCNFs//Fe2O3/NPC-350@Fe3C/EPCNFs) exhibits an energy density of 21.6 W h kg–1 at a power density of 499.05 W kg–1 with superior cycling stability (20000 cycles at 20 A g–1), indicating the feasibility of the prepared electrode for practical application in energy storage systems.

High-Performance High-Nickel Multi-Element Cathode Materials for Lithium-Ion Batteries

With the rapid increase in demand for high-energy-density lithium-ion batteries in electric vehicles, smart homes, electric-powered tools, intelligent transportation, and other markets, high-nickel multi-element materials are considered to be one of the most promising cathode candidates for large-scale industrial applications due to their advantages of high capacity, low cost, and good cycle performance. In response to the competitive pressure of the low-cost lithium iron phosphate battery, high-nickel multi-element cathode materials need to continuously increase their nickel content and reduce their cobalt content or even be cobalt-free and also need to solve a series of problems, such as crystal structure stability, particle microcracks and breakage, cycle life, thermal stability, and safety. In this regard, the research progress of high-nickel multi-element cathode materials in recent years is reviewed and analyzed, and the progress of performance optimization is summarized from the aspects of precursor orientational growth, bulk phase doping, surface coating, interface modification, crystal morphology optimization, composite structure design, etc. Finally, according to the industrialization demand of high-energy-density lithium-ion batteries and the challenges faced by high-nickel multi-element cathode materials, the performance optimization direction of high-nickel multi-element cathode materials in the future is proposed.

Evolution effect of -CF2- group amount in hydrofluoroether on the solvation structure and high voltage cycle performance of Ether-based localized High-concentration electrolytes

The high reactivity of Li metal and the security issues of electrolytes impede the practicality of lithium-metal batteries (LMBs). Herein, we propose a new localized high-concentration electrolyte (LHCE) in which, for the first time, 2,2,3,3-tetrafluoropropyl difluoromethyl ether (TDE) is employed as diluent in ether-based LHCE enables flame-retarded, broad electrochemical stability window, dendrite-free Li depositing, high Li anode cycling Coulombic efficiency (CE, 99.2%), and significantly improves cycling performance of Li||NMC811 batteries. It enables Li||NMC811 with limited 50 µm thickness Li metal anode and high loading capacity NMC811 cathode (14.8 mg cm−2, 2.96 mAh cm−2) to achieve a stable cycle with an ultrahigh cut-off voltage of 4.6 V. Molecular Dynamics (MD) simulation further corroborates the addition of hydrofluoroether diluents caused countersolvent effect to reinforce the association between Li+ cations and FSI− anions. However, an excessive amount of -CF2- in the diluent backbone would decrease the solubility of Li-salt in solvent, which is detrimental to the stability of electrolyte.

Metal-organic framework derived MnO@C/CNTs composite for high-rate lithium-based semi-solid flow batteries

Lithium-based semi-solid flow battery (LSSFB) is expected to be applied in the field of large-scale energy storage. However, the rate performance of LSSFBs is unsatisfied due to the poor conductivity of active materials and the unstable contact with conductive additives. Herein, carbon coated MnO quantum dots derived from MIL-100(Mn) were prepared. Such MnO quantum dots and carbon framework composite can not only increase the reactive active sites of MnO, but also avoid their agglomeration in the lithiation/delithiation process. Furthermore, the carbon framework and multi-walled carbon nanotubes (MWCNTs) are conducive to the rapid transport of electrons and can inhibit the volume expansion of MnO, achieving the high-rate performance and long cycling life. Moreover, MWCNTs can increase the suspension of the material and ensure the long-term stability of the slurry. These advantages endow the LSSFBs with high rate and long cycling performance. This work provides a promising strategy for the preparation of high-rate slurry electrode materials.