Enhanced Cycling Performance Research Articles

Interfacial Spinel Local Interlocking Strategy Toward Structural Integrity in P3 Oxide Cathodes.

P3-layered transition oxide cathodes have garnered considerable attention owing to their high initial capacity, rapid Na+ kinetics, and less energy consumption during the synthesis process. Despite these merits, their practical application is hindered by the substantial capacity degradation resulting from unfavorable structural transformations, Mn dissolution and migration. In this study, we systematically investigated the failure mechanisms of P3 cathodes, encompassing Mn dissolution, migration, and the irreversible P3-O3' phase transition, culminating in severe structural collapse. To address these challenges, we proposed an interfacial spinel local interlocking strategy utilizing P3/spinel intergrowth oxide as a proof-of-concept material. As a result, P3/spinel intergrowth oxide cathodes demonstrated enhanced cycling performance. The effectiveness of suppressing Mn migration and maintaining local structure of interfacial spinel local interlocking strategy was validated through depth-etching X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, and in situ synchrotron-based X-ray diffraction. This interfacial spinel local interlocking engineering strategy presents a promising avenue for the development of advanced cathode materials for sodium-ion batteries.

Enhanced cycle performance of Li ion battery by graphene sheets covering with SnO@SnO2 anode materials

Enhanced cycle performance of Li ion battery by graphene sheets covering with SnO@SnO2 anode materials

Synthesis of core–shell silicon–carbon nanocomposites via in-situ molten salt-based reduction of rice husks: A promising approach for the manufacture of lithium-ion battery anodes

Silicon (Si) has gained substantial interest as a potential component of lithium-ion battery (LIB) anodes due to its high theoretical specific capacity. However, conventional methods for producing Si for anodes involve expensive metal reductants and stringent reducing environments. This paper describes the development of a calcium hydride (CaH2)–aluminum chloride (AlCl3) reduction system that was used for the in-situ low-temperature synthesis of a core–shell structured silicon–carbon (Si–C) material from rice husks (RHs), and the material was denoted RHs-Si@C. Moreover, as an LIB anode, RHs-Si@C exhibited exceptional cycling performance, exemplified by 90.63 % capacity retention at 5 A g−1 over 2000 cycles. Furthermore, the CaH2–AlCl3 reduction system was employed to produce Si nanoparticles (Si NPs) from RHs (R-SiO2, where SiO2 is silica) and from commercial silica (C-SiO2). The R-SiO2-derived Si NPs exhibited a higher residual silicon oxides (SiOx) content than the C-SiO2-derived Si NPs. This was advantageous, as there was sufficient SiOx in the R-SiO2-derived Si NPs to mitigate the volumetric expansion typically associated with Si NPs, resulting in enhanced cycling performance. Impressively, Si NPs were fabricated on a kilogram scale from C-SiO2 in a yield of 82 %, underscoring the scalability of the low-temperature reduction technique.

Novel paddy-like Bi-Sb-Cu alloy fabricated via pulse reverse potential electrodeposition enabling high-performance sodium-ion batteries

Sodium-ion batteries (SIBs) have gained remarkable interest as cost-effective and scalable energy storage devices. Nevertheless, their further application has been significantly hindered due to the limited selection of desirable anode materials that can provide both high capacity and excellent cycling stability. Herein, we developed a hierarchical paddy-like Bi42.3Sb35.2Cu22.5 alloy anode on Cu foil via template-free pulse reverse potential electrodeposition. The Bi42.3Sb35.2Cu22.5 anode obtains a considerable specific capacity of 529.5 mAh·g−1 after 120 cycles with a remarkable capacity retention of 95.5 %, signifying a capacity loss of only 0.0375 % per cycle. However, Bi44.9Sb55.1 anodes obtained by the pulse potential electrodeposition strategy reveal a conventional irregular cluster structure, delivering only 64.5 mAh·g−1 after 100 cycles and also demonstrating inferior rate performance compared to Bi42.3Sb35.2Cu22.5 anodes. The enhanced cycling performance of the paddy-like Bi42.3Sb35.2Cu22.5 anode is primarily attributed to the introduced Cu-doped network facilitating the rapid diffusion of Na+ and also ensuring the stability of the electrode structure. Moreover, the unique paddy-like structure of Bi42.3Sb35.2Cu22.5 mitigates volume expansion-related stress and facilitates efficient charge transport through open channels. This is further corroborated by conducting CV measurements, indicating a greater capacitive contribution in the case of the Bi42.3Sb35.2Cu22.5 electrode compared to the Bi44.9Sb55.1 electrode. Additionally, SEM images show a stabilized surface morphology for the Bi42.3Sb35.2Cu22.5 electrode after cycling, demonstrating improved electrochemical performance. This work offers new insights into the development of high-performance anode materials for SIBs.

Correction: Enhanced cycle performance of Li ion battery by graphene sheets covering with SnO@SnO2 anode materials

Correction: Enhanced cycle performance of Li ion battery by graphene sheets covering with SnO@SnO2 anode materials

Ethylene Glycol-Choline Chloride Based Hydrated Deep Eutectic Electrolytes Enabled High-Performance Zinc-Ion Battery.

Aqueous rechargeable zinc-ion batteries (ARZIBs) are considered as an emerging energy storage technology owing to their low cost, inherent safety, and reasonable energy density. However, significant challenges associated with electrodes, and aqueous electrolytes restrict their rapid development. Herein, ethylene glycol-choline chloride (Eg-ChCl) based hydrated deep-eutectic electrolytes (HDEEs) are proposed for RZIBs. Also, a novel V10O24·nH2O@rGO composite is prepared and investigated in combination with HDEEs. The formulated HDEEs, particularly the composition of 1ml of EG, 0.5g of ChCl, 4ml of H2O, and 2M ZnTFS (1-0.5-4-2 HDEE), not only exhibit the lowest viscosity, highest Zn2+ conductivity (20.38mScm-1), and the highest zinc (Zn) transference number (t+ = 0.937), but also provide a wide electrochemical stability window (>3.2V vs ZnǁZn2+) and enabledendrite-free Zn stripping/plating cycling over 1000 hours. The resulting ZnǁV10O24·nH2O@rGO cellwith 1-0.5-4-2 HDEE manifests high reversible capacity of ≈365mAhg-1 at 0.1Ag-1, high rate-performance (delivered ≈365/223mAhg-1 at 0.1/10mAg-1) and enhanced cycling performance (≈63.10% capacity retention in the 4000th cycle at 10Ag-1). Furthermore, 1-0.5-4-2 HDEE support feasible Zn-ion storage performance across a wide temperature range (0-80°C) FInally, a ZnǁV10O24·nH2O@rGO pouch-cell prototype fabricated with 1-0.5-4-2 HDEE demonstrates good flexibility, safety, and durability.

Anchoring Active Li Metal in Oriented Channel by In Situ Formed Nucleation Sites Enabling Durable Lithium-Metal Batteries.

Lithium metal is the ultimate anode material for pursuing the increased energy density of rechargeable batteries. However, fatal dendrites growth and huge volume change seriously hinder the practical application of lithium metal batteries (LMBs). In this work, a lithium host that preinstalled CoSe nanoparticles on vertical carbon vascular tissues (VCVT/CoSe) is designed and fabricated to resolve these issues, which provides sufficient Li plating space with a robust framework, enabling dendrite-free Li deposition. Their inherent N sites coupled with the in situ formed lithiophilic Co sites loaded at the interface of VCVT not only anchor the initial Li nucleation seeds but also accelerate the Li+ transport kinetics. Meanwhile, the Li2Se originated from the CoSe conversion contributes to constructing a stable solid-electrolyte interphase with high ionic conductivity. This optimized Li/VCVT/CoSe composite anode exhibits a prominent long-term cycling stability over 3000h with a high areal capacity of 10 mAh cm-2. When paired with a commercial nickel-rich LiNi0.83Co0.12Mn0.05O2 cathode, the full-cell presents substantially enhanced cycling performance with 81.7% capacity retention after 300 cycles at 0.2 C. Thus, this work reveals the critical role of guiding Li deposition behavior to maintain homogeneous Li morphology and pave the way to stable LMBs.

Fast Li Replenishment Channels-Assisted Recycling of Degraded Layered Cathodes with Enhanced Cycling Performance and Thermal Stability.

The direct recycling of cathode materials in lithium-ion batteries is important for environmental protection and resource conservation. The key regeneration processes are composition replenishment and atom rearrangement, both of which depend on the migration and diffusion of atoms. However, for the direct recycling of degraded LiNi0.5 Co0.2 Mn0.3 O2 (D-NCM523) cathode, the irreversible phase transitions that accumulate during the long-term cycles block the Li diffusion channels with a high diffusion energy barrier, making it difficult to fully repair the layered structure and resulting in rapid capacity decay. To address the challenge, fast Li replenishment channels are rebuilt to regulate the surface phase and effectively assist the regeneration process with a reduced energy barrier. This method reduces the amount of Li supplement by >75% and shortens the sintering time (only 2h) to fully regenerate D-NCM523, compared to general direct recycling methods. The regenerated NCM523 (LCMB-NCM523) exhibits a satisfactory repaired specific capacity of 160mAhg-1 and excellent cycling stability, retaining 78% of its capacity after 300 cycles. In addition, LCMB-NCM523 is recycled with improved thermal decomposition peak temperature and enables 200 cycles even at 60°C, greatly improving safety. This work proposes a promising way for the large-scale direct regeneration of layered cathodes.

The Construction of Anion-Induced Solvation Structures in Low-concentration Electrolyte for Stable Zinc Anodes.

Aqueous zinc-ion batteries (ZIBs) are promising large-scale energy storage devices because of their low cost and high safety. However, owing to the high activity of H2O molecules in electrolytes, hydrogen evolution reaction and side reactions usually take place on Zn anodes. Herein, additive-free PCA-Zn electrolyte with capacity of suppressing the activity of free and solvated H2O molecules was designed by selecting the cationophilic and solventophilic anions. In such electrolyte, contact ion-pairs and solvent-shared ion-pairs were achieved even at low concentration, where PCA- anions coordinate with Zn2+ and bond with solvated H2O molecules. Simultaneously, PCA- anions also induce the construction of H-bonds between free H2O molecules and them. Therefore, the activity of free and solvated H2O molecules is effectively restrained. Furthermore, since PCA- anions possess a strong affinity with metal Zn, they can also adsorb on Zn anode surface to protect Zn anode from the direct contact of H2O molecules, inhibiting the occurrence of water-triggered side reactions. As a result, plating/stripping behavior of Zn anodes is highly reversible and the coulombic efficiency can reach to 99.43 % in PCA-Zn electrolyte. To illustrate the feasibility of PCA-Zn electrolyte, the Zn||PANI full batteries were assembled based on PCA-Zn electrolyte and exhibited enhanced cycling performance.

Enhancing Li-S Battery Performance with Limiting Li[N(SO2F)2] Content in a Sulfolane-Based Sparingly Solvating Electrolyte.

By enhancing the stability of the lithium metal anode and mitigating the formation of lithium dendrites through electrolyte design, it becomes feasible to extend the lifespan of lithium-sulfur (Li-S) batteries. One widely accepted approach involves the utilization of Li[N(SO2F)2] (Li[FSA]), which holds promise in stabilizing the lithium anode by facilitating the formation of an inorganic-dominant solid electrolyte interface (SEI) film. However, the use of Li[FSA] encounters limitations due to inevitable side reactions between lithium polysulfides (LiPSs) and [FSA] anions. In this study, our focus lies in precisely controlling the composition of the SEI film and the morphology of the deposited lithium, as these two critical factors profoundly influence lithium reversibility. Specifically, by subjecting an initial charging process to an elevated temperature, we have achieved a significant enhancement in lithium reversibility. This improvement is accomplished through the employment of a LiPS sparingly solvating electrolyte with a restricted Li[FSA] content. Notably, these optimized conditions have resulted in an enhanced cycling performance in practical Li-S pouch cells. Our findings underscore the potential for improving the cycling performance of Li-S batteries, even when confronted with challenging constraints in electrolyte design.

Enhanced cycling performance of lithium-ion batteries with V2O5 as cathode by Co-doping for structural stability

Enhanced cycling performance of lithium-ion batteries with V2O5 as cathode by Co-doping for structural stability

Composition Analysis of the Solid Electrolyte Interface of NaK Anodes in Na-Ion Batteries.

Sodium-ion batteries have emerged as a promising alternative to Li-ion batteries due to the abundance of sodium. However, anodes in Na-ion batteries face challenges such as dendrite formation and an unstable solid electrolyte interface layer. To address these challenges, NaK liquid metal alloy anodes have been proposed as an alternative because they do not form dendrites. In our study, we demonstrate that the NaK alloy anode interacts with the commonly used ethylene carbonate and dimethyl carbonate electrolyte, leading to a continuously growing unstable SEI layer, evidenced by cycling failures under 100 cycles and an increasing charge transfer resistance in electrochemical impedance spectroscopy studies. In situ surface-enhanced Raman spectroscopy and X-ray photoelectron spectroscopy reveal that over the course of cycling the surface of the NaK anode becomes increasingly sodium-rich. After 30 cycles, XPS analysis detects only trace amounts of potassium on the NaK anode surface. When the electrolyte is analyzed postcycling using inductively coupled plasma optical emission spectroscopy, there is a noticeable increase in potassium levels, suggesting that potassium metal dissolves into the electrolyte. The introduction of a 10 wt % fluoroethylene carbonate additive can mitigate this problem to some extent, enabling an enhanced cycling performance of up to 800 cycles at 1C. Nevertheless, the dissolution of K metal is still evident in the XPS results, albeit to a lesser degree. These discoveries provide valuable insights for designing a more robust SEI layer for the NaK anode.

Multi-functional additive to enhance cycling performance of Zn anode in aqueous battery

The growth of dendritic dendrites and side reactions at the zinc anode result in poor cycling stability of the aqueous zinc-ion battery (AZIBs). Here, we report on a multifunctional additive, Sodium lactobionate (SL), that achieves more stable cycling performance. SL molecule can loosen the solvation structure of water and Zn2+, inhibit corrosion and hydrogen evolution reactions, and regulate ion deposition in AZIBs. Under the action of SL, the Zn//Zn symmetric battery achieves an ultra-long stable cycle of up to 2150 h at a current density of 2 mA·cm−2 and an area capacity of 1 mAh cm−2 and Zn//NVO can still perform 1110 cycles at the current density of 2 A g−1 and maintain the reversible specific discharge capacity of 179 mAh g−1. In addition, at 2 mA cm−2 and 0.5 mAh cm−2, the Zn//Cu asymmetric battery achieved up to 350 cycles with a coulomb efficiency of 99.5 %.

Pedal Quadrant-Specific Strength and Conditioning Considerations for Endurance Cyclists

ABSTRACT The performance-enhancing effects of strength training on cycling are well documented with findings from research, demonstrating resistance training with heavy loads conducted 2–3 times per week for at least 8 weeks can improve power output (maximal and submaximal), extend time to exhaustion, and reduce completion time for set distances, while not adding to the total body mass. Despite the evident benefits of strength training, there remains a lack of consensus regarding the most effective exercises to enhance endurance cycling. This uncertainty is evident when considering movement-specific exercises to enhance dynamic transfer to cycling. A range of lower-limb exercises involving hip, knee, and ankle flexion and extension seems to enhance cycling performance more so than static or single-joint exercises. These improvements may be attributed to enhanced coordination and improved pedaling technique. This study presents 5 strength training exercises designed to target cycling pedaling quadrants and replicate the unilateral opposing nature of cycling (simultaneous flexion and extension of the legs) to enhance transfer from weight room-based strength training to the bike. These exercises are presented in example programs alongside established “traditional” exercises that may be used to guide the development of strength training for cyclists.

Mitigating magnetic frustration to improve single-crystalline nonstoichiometric Li1.06Ni0.90Mn0.04O2 for lithium-ion batteries

A molten salt-assisted synthesis and Li-refeeding strategy is applied to prepare single-crystalline slightly Li-rich Li1.06Ni0.90Mn0.04O2 with low magnetic moment and mitigated Li+/Ni2+ cation mixing, which enhances cycling performance.

Enhanced cycling performance of B-doped LiNi0.8Co0.1Mn0.1O2 cathodes prepared by the solid-state method

Boron doped Ni-rich cathodes are successfully prepared by the solid-state method. The formation of strong B–O bonds enhances the structural stability of NCM811.

Harnessing medium entropy and oxygen defects in spinel ferrite cathodes for enhanced cycling performance in lithium–sulfur batteries

In this study, medium-entropy spinel ferrites were synthesized and oxygen vacancies were intentionally created in the medium-entropy spinel ferrites. The electrochemical properties of the materials as cathode materials for LSB were investigated.

Enhanced Cycle Performance of NiCo2O4/CNTs Composites in Lithium-Air Batteries

The lithium-air battery is a new type of secondary battery technology that is currently receiving a lot of attention in the field of power storage technology. These batteries are known to offer high energy densities and potentially longer driving ranges. In this study, NiCo2O4 and CNTs were used to create a composite for use as the cathode of a Li-air battery. Improving the 3D needl-like structure that provides extensive transport channels for electrolyte infiltration and numerous sites facilitated charge transfer reactions and the synergistic effect of highly electrocatalytic NiCo2O4 with pronounced activity and high conductive CNTs, with the synthesized NiCo2O4@CNTs composites exhibiting active catalytic performance for both OER and ORR reactions. It also showed improved cycle performance at high current densities. NiCo2O4@CNTs composites were successfully fabricated using a hydrothermal method together with a sequential annealing treatment. The components of the completed composite were confirmed using TGA, XRD, and SEM, and the specific surface area was analyzed using BET. The composite was performed for over 120 cycles at a current density of 200 mA∙g−1, and 500 mA∙g−1 was achieved under the capacity limiting condition of 500 mAh∙g−1. The charging/discharging characteristics were compared under various current densities, exhibiting stable cyclability. The high catalytic activity of NiCo2O4 oxide supports its potential use as a cathode in Li-air batteries.

Enhanced Cycling Performance of Li–S Cells by Mitigation of Lithium Polysulfides Encompassing Palladated Porous Aromatic Polymer-Coated Membranes

Enhanced Cycling Performance of Li–S Cells by Mitigation of Lithium Polysulfides Encompassing Palladated Porous Aromatic Polymer-Coated Membranes

The Construction of Binary Phase Electrolyte Interface for Highly Stable Zinc Anodes.

Metal zinc is a promising anode candidate of aqueous zinc-ion batteries due to high theoretical capacity, low cost, and high safety. However, it often suffers from hydrogen evolution reaction (HER), dendrite growth, and formation of by-products. Herein, a triethyl phosphate (TEP)/H2 O binary phase electrolyte (BPE) interface is developed by introducing TEP-based electrolyte-wetted hydrophobic polypropylene (PP) separator onto the Zn anode surface. The equilibrium of the BPE interface depends on the comparable surface tensions of H2 O-based and TEP-based electrolytes on hydrophobic PP separator surfaces. The BPE interface induces Zn2+ solvation structure conversion from [Zn(H2 O)x ]2+ to [Zn(TEP)n (H2 O)y ]2+ , where most solvated H2 O molecules are removed. In [Zn(TEP)n (H2 O)y ]2+ , the residual H2 O molecules can be further constrained by the formation of H bonds between TEP and H2 O molecules. Consequently, the ionization of solvated H2 O molecules is effectively suppressed, and HER and by-products are effectively restricted on Zn anode surfaces in BPE. As a result, Zn anodes exhibit a high Coulombic efficiency of 99.12% and superior cycling performance of 6000h, which is much higher than the case in single-phase aqueous electrolytes. To illustrate the feasibility of BPE in full cells, the Zn/Alx V2 O5 batteries are assembled based on the BPE and exhibited enhanced cycling performance.