High Rate Performance Research Articles

Van der Waals gap modulation of graphene oxide through mono-Boc ethylenediamine anchoring for superior Li-ion batteries.

Li-ion batteries stand out among energy storage systems due to their higher energy and power density, cycle life, and high-rate performance. Development of advanced, high-capacity anodes is essential for enhancing their performance, safety, and durability, and recently, two-dimensional materials have garnered extensive attention in this regard due to distinct properties, particularly their ability to modulate van der Waals gap through intercalation. Covalently intercalated Graphene oxide interlayer galleries with mono-Boc-ethylenediamine (GO-EnBoc) was synthesized via the ring opening of epoxide, forming an amino alcohol moiety. This creates three coordination sites for Li ion exchange on the graphene oxide nanosheets' surface. Consequently, the interlayer d-spacing expands from 8.47 Å to 13.17 Å, as anticipated. When explored as an anode, Li-GO-EnBoc shows a significant enhancement in the stable and reversible capacity of 270 mA h g-1 at a current density of 25 mA g-1 compared to GO (80 mA h g-1), without compromising the mechanical or chemical stability. Through 13C, 7Li and 6Li MAS NMR, XPS, IR, Raman microscopy, and density functional theory (DFT) calculations, we confirm the positioning of Li+ ions at multiple sites of the interlayer gallery, which enhances the electrochemical performance. Our findings suggest that these novel systematically modulated van der Waals gap GO-engineered materials hold promise as efficient anodes for Li-ion batteries.

Failure mechanisms of the Li(Ni0.6Co0.2Mn0.2)O2-Li4Ti5O12 lithium-ion batteries in long-time high-rate cycle.

With the ever-growing widespread use of lithium-ion batteries in heavy machinery and daily life, the demand for improved longevity and high-rate performance is escalating. While Li4Ti5O12 (LTO) batteries excel in safety and cycling performance, their full potential for long-term, high-rate cycling still yet remains unrealized. In this paper, we present an analysis of a pouch battery with an LTO anode system that was cycled for an extended period at high rates. We compared the performance changes and internal component properties between fresh and cycled batteries. Our results reveal that, after tens of thousands of high-rate cycles, microcracks emerged on the cathode electrode material (NCM622) particles of the battery, whereas the LTO remained largely unchanged. Additionally, we observed significant electrolyte reduction, characterized the separator surface, and measured its properties. Our findings indicate that the electrolyte reactions are the primary cause of battery failure, leading to capacity fading and impedance increase. This research provides valuable insights into the failure mechanisms of lithium-ion batteries at high rates, thus contributing to the improvement of high-rate lithium-ion batteries.

Highly stable manganese oxide cathode material enabled by Grotthuss topochemistry for aqueous zinc ion batteries

This research reports the presence of a synergistic effect among vacancies, lattice water and nickel ions on enhancing the hydrated protons hopping via the Grotthuss mechanism for high performance zinc ion battery cathodes.

Conductive V2O3 electrocatalyst on carbon hollow spheres to accelerate polysulfide conversion for long-cycle and high-rate lithium sulfur batteries

The V2O3/C-HS material was prepared by a hard template and impregnation method. When applied in lithium–sulfur batteries, it shows excellent long-cycle and high-rate performance.

A tricycloquinazoline based 2D conjugated metal-organic framework for robust sodium-ion batteries with co-storage of both cations and anions.

There is growing interest in 2D conjugated metal-organic frameworks (2D c-MOFs) for batteries due to their reversible redox chemistry. Nevertheless, currently reported 2D c-MOFs based on n-type ligands are mostly focused on the storage of cations for batteries. Herein, we successfully synthesize nitrogen-rich and electron-deficient p-type ligand-based Ni3(HATQ)2 assembled from 2,3,7,8,12,13-hexaaminotricycloquinazoline (HATQ), and the ion co-storage feature of cations and anions in sodium ion batteries (SIBs) is demonstrated for 2D c-MOFs for the first time. The redox chemistry from the p-type ligand and π-d hybridization center endows the Ni3(HATQ)2 cathode with high capacity and good rate performance, especially excellent capacity retention of 95% after 1000 cycles. These findings provide a promising avenue for the exploration of other p-type multidentate chelating ligands toward new 2D c-MOFs and expand the application of 2D c-MOFs in energy storage systems.

A Neuro Phenotypic Evolution Algorithm for Recognizing Human Motion Type

Living in the modern world requires having a precise, intelligent system that may be suggested to do various activities. Due to the scalability of AI algorithms, we have proposed a phenotypic Evolutionary Algorithm (EA)-based system to assist the Artificial Neural Network algorithm (ANN) in the learning process. Combining the two strategies can result in a smart neuro-evolutionary model that is effective in accomplishing significant duties in various domains. The suggested multi-layer neural algorithm's design creates the conditions for learning via the EA’s processes of crossover, mutation, and selection. To aid in the selection and crossover processes, the learning process phase breaks up the original ANN into multiple ANNs according to the number of hidden layers. ANNs are ranked from worst to best in the selection phase based on the soring function that is applied to the fitness list. The fitness list retains each ANN’s accuracy even after breaking apart the original ANN. The crossover procedure is then applied between the two worst and best ANNs. Mutation provides a means of improvement for the less effective ANNs. Following completion of these processes, the ANN algorithms are combined to create a single ANN algorithm. The Vicon mobile robot (SCITOS G5) system’s multi-dimensional data, which extracted both aggressive and typical human movement, as well as Human Activity Recognition (HAR) datasets extracted by smartphones, both have been applied using the suggested method. The system achieved a high performance and efficiency rate on the intended recognition problem

Design of a bipolar organic small-molecule cathode with mesoporous nanospheres structure for long lifespan and high-rate Li-storage performance.

Organic small-molecule compounds have become promising cathode materials for high-performance lithium-ion batteries (LIBs) due to their high theoretical capacity, efficient utilization of active sites, low cost, and sustainability. However, severe dissolution and poor electronic conductivity limit their further practical applications. Herein, we have synthesized an insoluble organic small molecule, ferrocenyl-3-(λ1-azazyl) pyrazinyl [2,3-f] [1,10] phenanthrolino-2-amine (FCPD), by grafting ferrocene onto pyrazino[2,3-f] [1,10] phenanthroline-2,3-diamine (PPD). The combination of ferrocene (p-type Fe2+ moiety) and PPD (n-type C[double bond, length as m-dash]N groups) in a bipolar manner endows the target FCPD cathode with an increased theoretical capacity and a wide voltage window. The highly conjugated π-π aromatic skeleton inside enhances FCPD's electron delocalization and promotes strong interaction between FCPD units. Additionally, the mesoporous structure within the FCPD can provide numerous electroactive sites, contact area, and ion diffusion channels. Benefiting from the bipolar feature, aromatic, and mesoporous structure, the FCPD cathode demonstrates a large capacity of 250 mA h g-1 at 0.1 A g-1, a long lifespan of 1000 cycles and a high-rate capability of 151 mA h g-1 at 5 A g-1 along with a wide voltage window (1.2-3.8 V). Additionally, in situ synchrotron FT-IR and ex situ XPS reveal its dual ion storage mechanism in depth. Our findings provide essential insights into exploring the molecular design of advanced organic small molecules.

K-birnessite-MnO2/hollow mulberry-like carbon complexes with stabilized and superior rate performance for aqueous magnesium ion storage.

Manganese oxides are commonly employed as a cathode for magnesium ion storage in aqueous magnesium ion hybrid supercapacitors (MHS). However, sluggish reaction kinetics still hinders their practical application. Herein, we designed K-birnessite-MnO2 and electrostatically spun mulberry-like carbon composites (K-MnO2/HMCs) via an in situ growth technique. Benefiting from the 3D conductive carbon network substrate, the in situ fabricated K-MnO2 exhibits more active sites and provides more interfacial contact area between the electrode material and the electrolyte. This improvement enhances its conductivity, facilitating the rapid transfer of electrons, diffusion of ions, and redox reactions. As a result, K-MnO2/HMC-based MHS achieves a specific capacity of 168 mA h g-1 at 0.5 A g-1, simultaneously exhibiting a superior energy density of 111.1 W h kg-1 at a power density of 505 W kg-1. Furthermore, it demonstrates excellent high rate performance and a long cycling life for aqueous magnesium ion storage, offering new insights for MHS applications.

Sn0.1-Li4Ti5O12/C as a promising cathode material with a large capacity and high rate performance for Mg-Li hybrid batteries.

The development prospects of conventional Li-ion batteries are limited by the paucity of Li resources. Mg-Li hybrid batteries (MLIBs) combine the advantages of Li-ion batteries and magnesium batteries. Li+ can migrate rapidly in the cathode materials, and the Mg anode has the advantage of being dendrite-free. In this study, a type of Li4Ti5O12 composite material doped with Sn4+ and a conductive carbon skeleton (Li4Ti4.9Sn0.1O12/C, Sn0.1-LTO/C) was prepared by a simple one-pot sol-gel method. The doped Sn4+ replaces part of Ti4+ in the crystal lattice, which makes Ti3+ require charge compensation, thus improving the ionic conductivity. The intervention of the conductive carbon skeleton further improves the conductivity of the Sn0.1-LTO/C composite material. The performance of Sn0.1-LTO/C as the cathode of MLIBs is explored. The initial discharge capacity was 159.1 mA h g-1 at 0.5 C, and it was maintained at 105 mA h g-1 even after 500 cycles. The excellent electrochemical performance is attributed to a small amount of Sn doping and the involvement of the conductive carbon skeleton, which indicated that the Sn0.1-LTO/C composite material provides great potential application in MLIBs.

Design of novel Cu-doped SnS2 on carbon cloth as a binder-free anode to improve high-rate performance of sodium ion battery

Binder-free Cu-doped SnS2@CC electrodes with vertical grown nanosheet arrays are proposed. The highest capacity of 1092.8 mA h g−1 was got at 0.1 A g−1, indicating that doping Cu can improve rate performance of SnS2, but excess Cu doping leads to reduced rate performance with overloaded defects.

Mo/PANI co-modified ultra-high nickel NCM9622 cathode composite with excellent cycle stability and high-rate performance for power batteries

Ultra-high nickel layered cathode materials with very high specific capacity are the future direction of power battery development, but they also face many challenges such as poor cycling stability and...

Boosting the high-rate performance of lithium-ion battery anodes using MnCo2O4/Co3O4 nanocomposite interfaces.

Herein, a mesoporous MnCo2O4/Co3O4 nanocomposite was fabricated using a polyvinylpyrrolidone (PVP)-assisted hydrothermal synthesis method by maintaining only the non-stoichiometric ratio of Mn and Co (2 : 6), leading to an extra phase of Co3O4 coupled with MnCo2O4. Microstructural analysis showed that the obtained sample has a uniform nanowire-like morphology composed of interconnected nanoparticles. The stoichiometric ratio (2 : 4) was maintained to synthesize pure MnCo2O4 for comparative analysis. However, the obtained structure of pure MnCo2O4 was found to be irregular and fragile. After their employment as anode-active materials, the nanocomposite electrode showed superior high rate capability (1043.8 mA h g-1 at 5C) and long-term cycling stability (773.6 mA h g-1 after 500 cycles at 0.5C) in comparison to the pure MnCo2O4 electrode (771.5 mA h g-1 at 5C and 638.9 mA h g-1 at 0.5C after 500 cycles). It was believed that the extra phase of Co3O4 may also participate in the electrochemical reactions due to its high electrochemically active nature. Benefiting from the appealing architectural features and striking synergistic effect, the integrated MnCo2O4/Co3O4 nanocomposite anode exhibits excellent electrochemical properties and high cycle stability for LIBs.

Understanding the fast kinetics and mechanism of sodium storage in antimony using ab initio grand canonical Monte Carlo simulation and operando X-ray scattering

Using ai-GCMC simulations, operando WAXS, and kinetics analysis, we found that the high-rate performance of Sb as an alloy anode in Na-ion batteries is due to the presence of an amorphous intermediate phase formed during sodiation and desodiation.

Improving high-voltage high-rate performance of P2 layered oxide cathode by dual-ion doping strategy for sodium-ion batteries

P2-Na0.67Ni0.33Mn0.67O2 is a promising cathode in sodium-ion batteries for large-scale energy storage applications due to their advantages of low cost, high energy density, superior sodium ion conductivity, and good air...

A zinc coordination supramolecular network synergized manganese dioxide achieves high-rate lithium–sulfur batteries

Zinc coordination supramolecular network (Zn-CSN) combined with MnO2 to obtained the Zn-CSN@MnO2, Zn-CSN@MnO2 as a sulfur host achieves high-rate performance of lithium–sulfur batteries.

Defect engineering of air-stable Li5FeO4 towards an ultra-high capacity cathode prelithiation additive.

Antifluorite-type Li5FeO4 (LFO) belongs to a class of promising prelithiation materials for next-generation high-energy lithium-ion batteries. Unfortunately, the incomplete de-lithiation performance and inferior air stability hinder its application. In this work, ultra-high capacity is achieved by selective doping of Zr into the Fe sites (LFO-Zr) of LFO to form a large number of defects. The underlying defect formation mechanism is comprehensively investigated using density functional theory, revealing that such selective site doping not only enlarges the unit cell volume but also induces Li vacancies into the structure, both of which facilitate lithium-ion migration at a high-rate and promote the redox of oxygen anions. As a result, under 0.05 and 1C rates, the capacity of LFO-Zr reaches 805.7 and 624.5 mA h g-1, which are 69.0 and 262.0 mA h g-1 higher than those of LFO, translating to an increase of 9.4% and 73.3%, respectively. In addition, LFO-Zr exhibits excellent electrochemical performance in a humidity of 20%, with a high capacity of 577.6 mA h g-1 maintained. With the LFO-Zr additive, the full cell delivered 193.6 mA h g-1 for the initial cycle at 0.1C. The defect engineering strategy presented in this work delivers insights to promote ultra-high capacity and high-rate performance of air-stable LFO.

Nitrogen-sulfur co-doped ZIF-8-derived carbon materials for supercapacitors with low self-discharge

Supercapacitors (SCs) have attracted extensive attention due to the properties of high power density, long cycle life, and high rate performance. However, the high self-discharge is one giant challenge for long-term energy storage applications of SC. Herein, we prepared a high-performance SC with low self-discharge based on nitrogen-sulfur co-doped ZIF-8-derived (NS-PC) materials. The synergistic effects of high-temperature carbonization and nitrogen-sulfur (N-S) doping are systematically investigated. With a carbonization temperature of 900 °C, assisted with N-S doping, the maximum specific capacitance of the NS-PC-900//NS-PC-900 symmetrical SC is 42.7 F g−1, while the power densities range from 650 to 13,000 W kg−1 at the energy densities of 10.04–7.5 Wh kg−1. The specific capacitance remains 95.7 % even after 20,000 charge-discharge cycles. More importantly, the as-prepared NS-PC-900//NS-PC-900 SC exhibits an ultra-low self-discharge rate of solely 0.025 V h−1 within 24 h. This work provides a universal strategy to fabricate high-performance SCs with low self-discharge.

MoS2@CoS2 heterostructured tube-in-tube hollow nanofibers with enhanced reaction reversibility and kinetics for sodium-ion storage

Rational synergism in spatial nanostructures and heterogeneity are effective ways to enhance reaction reversibility and kinetics of materials for sodium-ion battery electrodes. Herein, we have designed MoS2@CoS2 heterostructured tube-in-tube hollow nanofibers via simple electrospinning, pyrolysis and sulfuration processes. The unique double-walled tubular structure resulted from a stepwise crystallization accompanied by pyrolysis volume shrinkage. It has appropriate void space and abundant MoS2@CoS2 heterointerfaces that can effectively avoid the volumetric change during the reaction process and accelerate the whole infiltration of the electrolyte. The formed MoS2/CoS2 heterojunction introduces a built-in electric field, which increases the adsorption energy and reduces the migration energy barrier of sodium ions. The synergies between distinctive hollow structures and heterogeneous compositional advantages lead to enhanced electrochemical performance for sodium storage with remarkable reversible capacity (858.3 mAh g–1 at 0.5 A g–1), high-rate performance (555.7 mAh g–1 at 5 A g–1), and superior long-term cycling stability (399.6 mAh g–1 after 1400 cycles at 8 A g–1). This rational spatial structures and heterogeneity synergetic strategy provide favorable inspiration for designing extraordinary performance electrode materials for sodium-ion batteries.

Fabrication of robust mechanical NiCo nanocubes for lithium metal anode with superior high rate performance

The incorporation of a conductive three-dimensional (3D) scaffold in lithium metal anodes (LMAs) represents one of the most effective strategies for mitigating the uncontrolled formation of lithium dendrites. In this study, a promising substrate is fabricated by one-step co-deposition of NiCo nanocubes on carbon fiber composite (CFC). The bimetallic nanocubes offer an abundance of lithiophilicity sites and exhibit exceptional mechanical properties, thereby enhancing the stability of the electrode. By incorporating pyridine and pyrrole nitrogen, along with the synergistic effect of bimetal ions, the stability of solid electrolyte interphase (SEI) film is also enhanced, interface resistance is reduced, and uniform lithium metal deposition is achieved, effectively inhibiting dendrite growth especially at high current densities, with a lifespan up to 5660 h at ultra-high current density up to 40 mA cm−2. When paired with LiFePO4, the full battery exhibits satisfied dynamic stability and ultra-long cycle stability during repeated shelving, maintaining good capacity retention after 2890 cycles at 1C. This work provides a new idea for the practical application of lithium metal battery.

Solution Combustion Synthesis of Submicron-Sized Titanium Niobium Oxide Anodes for High-Rate and Ultrastable Lithium-Ion Batteries.

Recently, the development of high-rate performance lithium-ion batteries is crucial for the development of next-generation energy storage systems. Nanoarchitecturing of the electrode material is a common strategy to improve the effective Li+ diffusion transport rate. However, this method often results in a reduction of volumetric energy density and battery stability. In this work, we propose a different strategy by synthesizing submicron-sized Ti2Nb10O29 (s-TNO) as a durable high-rate anode material using a facile and scalable solution combustion method, eliminating the dependence nanoarchitectures. The s-TNO electrode material exhibits a large tunnel structure and an excellent pseudocapacitive performance. The results show that this electrode material delivers a commendable reversible capacity of 238.7 mAh g-1 at 0.5 C and retains 78.2% of its capacity after 10,000 cycles at 10 C. This work provides a valuable guide for the synthesis of submicron-structured electrode materials using the solution combustion method, particularly for high-capacity, high-rate, and high-stability electrode materials.