Lithium Storage Behavior Research Articles

Superior anodic lithium storage behavior of organic pigment 2,9-dimethylquinacridone

Abstract Organic anode materials are of great importance for the development of lithium ion batteries (LIBs) with less reliance on inorganic minerals. In this work, it is found that 2,9-dimethylquinacridone (2,9-DMQA), an organic pigment, can have excellent electrochemical performances when serving as the anode material in LIBs. 2,9-DMQA based LIB anode manifests a high specific capacity of 1150 mAh g−1 at 0.1 A g−1. Even at a high current density of 5.0 A g−1, the capacity of 2,9-DMQA can still be retained at ~385 mAh g−1, outperforming many recently reported LIB anodes. The results from experiments and calculation suggest that 2,9-DMQA can reversibly associate with ~22Li+, corresponding to a theoretical capacity of 1732 mAh g−1. Additionally, the full-cell with 2,9-DMQA as anode and LiCoO2 as cathode can deliver the energy and power density of 325.8 Wh kg−1 and 1137.1 W kg−1, respectively, which are better than most of recently reported full-cells, implying the intriguing potential of the 2,9-DMQA anode in organic LIBs.

Atomic layer deposition of TiO2 shells on CoSe2 nanorods towards enhanced lithium storage performance

Surface modification via atomic layer deposition (ALD) of metal oxides (ex., TiO2) has been suggested as an effective strategy to enhance the electrochemical performance of high-specific-capacity electrode materials. Herein, we study the lithium storage behavior of TiO2 coated CoSe2 nanorods (TiO2@CoSe2), in which a thin layer of TiO2 shell is deposited via a conventional ALD method. The effects of the TiO2 deposition on the structural and electrochemical characteristics of the CoSe2 nanorods are systematically investigated. When applied as anodes for LIBs, the TiO2@CoSe2 electrode displays much enhanced lithium storage performance including higher specific capacity, better cycle stability and rate capability, delivering a discharge capacity of 999.2 mA h/g after 300 cycles at 200 mA/g and an exceptional capacity of 723.7 mA h/g after 430 cycles even at high current density of 500 mA/g, which is much higher than that of the bare CoSe2 electrode (only 145.4 mA h/g after 220 cycles at 200 mA/g).

Sulfur and nitrogen in-situ co-doped hierarchical spherical porous carbon for efficient lithium storage

Abstract A new strategy is presented to fabricate sulfur and nitrogen in-situ co-doped hierarchical spherical porous carbon (SNHSPC) and porous carbon nanotube (PCNT) from conjugated microporous polymer using alkynyl monomers and dibromine aromatic compounds as the building blocks through Sonogashira–Hagihara cross-coupling reactions for efficient lithium storage. SEM, XRD, TEM, XPS, nitrogen adsorption/desorption analysis and Raman spectrum were used to determine the structure of SNHSPC and PCNT. SNHSPC is hierarchical spherical porous carbon particles constituted by aggregated porous nano-fibers, which is distinctly different from those of PCNT. SNHSPC feature hierarchical spherical porous carbon, high specific surface area and homogeneous S and N co-doping, which enable a superior lithium storage behavior. The synergy of hierarchically porous structure and dual heteroatoms make SNHSPC afford a high lithium storage capacity, outstanding cycling stability and large rate performance, which are all superior to those of PCNT. The initial reversible capacity of SNHSPC is as high as 776 mA h g−1 at 0.1 A g−1.

Dynamic Covalent Synthesis of Crystalline Porous Graphitic Frameworks

Summary Porous graphitic framework (PGF) is a two-dimensional (2D) material that has emerging energy applications. An archetype contains stacked 2D layers, the structure of which features a fully annulated aromatic skeleton with embedded heteroatoms and periodic pores. Due to the lack of a rational approach in establishing in-plane order under mild synthetic conditions, the structural integrity of PGF has remained elusive and ultimately limited its material performance. Here, we report the discovery of the unusual dynamic character of the C=N bonds in the aromatic pyrazine ring system under basic aqueous conditions, which enables the successful synthesis of a crystalline porous nitrogenous graphitic framework with remarkable in-plane order, as evidenced by powder X-ray diffraction studies and direct visualization using high-resolution transmission electron microscopy. The crystalline framework displays superior performance as a cathode material for lithium-ion batteries, outperforming the amorphous counterparts in terms of capacity and cycle stability.

A new spinel high-entropy oxide (Mg0.2Ti0.2Zn0.2Cu0.2Fe0.2)3O4 with fast reaction kinetics and excellent stability as an anode material for lithium ion batteries.

It is well known that transition metal oxides (TMOs) have attracted extensive attention as promising anodes for next-generation lithium ion batteries (LIBs) owing to their low cost and high theoretical capacities. However, the huge volume changes upon lithiation/delithiation cycling gradually cause drastic particle pulverization in the electrodes, thus leading to fast capacity fading and limiting their practical applications. High-entropy oxides with enhanced electronic conductivity and multiple electrochemically active elements display stepwise lithium storage behaviors, thus efficiently alleviating the volume change induced electrode pulverization problem. Herein, we report the synthesis of a new kind of spinel (Mg0.2Ti0.2Zn0.2Cu0.2Fe0.2)3O4 material via a facile one-step solid state reaction method and subsequent high-energy ball-milling. When used as anodes for LIBs, the submicrometer-sized (Mg0.2Ti0.2Zn0.2Cu0.2Fe0.2)3O4 particles exhibit superior lithium storage properties, delivering a large reversible capacity of 504 mA h g−1 at a current density of 100 mA g−1 after 300 cycles, and notably an exceptional rate capacity of 272 mA h g−1 at 2000 mA g−1. Our work highlights that rational design of high-entropy oxides with different electrochemically active elements and novel structures might be a useful strategy for exploring high-performance LIB anode materials in next-generation energy storage devices.

Solid-state template-free fabrication of uniform Mo2C microflowers with lithium storage towards Li-ion batteries

Abstract Herein, we first report one-step synthesis of uniform Mo2C microflowers (MCMFs) from low-cost precursors via industrialized solid-state strategy. With fine optimization in precursor ratio and pyrolysis temperatures, the as-fabricated MCMFs are assembled well with interconnected single-crystalline nanosheet subunits. More encouragingly, the resultant MCMFs are further highlighted as a competitive anode with robust and long-duration lithium-storage behaviors towards high-performance Li-ion batteries

Hollow Co2P/Co-carbon-based hybrids for lithium storage with improved pseudocapacitance and water oxidation anodes

Abstract A porous hollow hybrid nanoarchitecture that consist of Co2P/Co nanoparticles confined in nitrogen-doped carbon (NC) and carbon nanotube (CNT) hollow nanocubes (denoted as H-Co2P/Co-NC/CNT) has been rational designed as anode for lithium ion batteries (LIBs) and electrocatalytic oxygen evolution reaction (OER). Such design involves simple synthetic process of using metal-organic frameworks (MOFs) as sacrificial precursor. The uniform cubic-shaped H-Co2P/Co-NC/CNT hybrid is investigated with several intriguing advantages, including improved structural integrity, superior electronic conductivity, hollow architecture and large specific surface area and so on. The as-synthesized H-Co2P/Co-NC/CNT displays excellent lithium storage behaviour in terms of long cycle life (> 500 cycles), remarkable rate performance (up to 5 A g−1), high reversible capacity (601 mA h g−1 at 0.2 A g−1) and high pseudocapacitance behavior. Besides, it also delivers a superior catalytic property for OER with a small Tafel slope of 45.3 mV dec−1 and overpotential of 256 mV (at 10 mA cm-2). The excellent performance can be attributed to the synergistic effect between Co2P/Co and NC/CNT, leading to enhanced conductivity through high pseudocapacitance contribution. This present work demonstrates that MOF-derived H-Co2P/Co-NC/CNT hybrid is a promising candidate for high-performance multifunctional energy systems.

Hydrothermal synthesis of hierarchical CoMoO4 microspheres and their lithium storage properties as anode for lithium ion batteries

Transition metal oxides have attracted extensive attention as promising anodes for lithium ion batteries (LIBs) owing to their low cost and high theoretical capacities. However, the large volume changes upon lithiation/delithiation cycling gradually causes the drastic particle pulverization in the electrodes, thus leading to the fast capacity fading and limiting their practical applications. Ternary metal oxides with enhanced electronic conductivity and multiple electrochemically active sites display stepwise lithium storage behaviors, thus efficiently alleviating the volume change induced electrode pulverization problem. Herein, we report the synthesis of hierarchical CoMoO4 microspheres assembled from nanosheets via a facile hydrothermal method and subsequently annealing. When used as anodes for LIBs, the CoMoO4 electrode exhibits superior lithium storage properties, delivering large reversible capacities of 1008 and 896 mA h/g at current densities of 200 and 500 mA/g after 50 cycles, respectively, and notably an exceptional rate capacity of 444 mA h/g at 2000 mA/g. Design of ternary metal oxides with different electrochemically active components and novel nanostructures might be an useful strategy for exploring high-performance LIB anode materials in the next-generation energy storage devices.

Solution-processed organic PDI/CB/TPU cathodes for flexible lithium ion batteries

Flexible organic cathodes with 3,4,9,10-perylenetetracarboxylic diimide (PDI) as the active component, carbon black (CB) as the conductive agent and thermoplastic polyurethane (TPU) as the elastomeric matrix are obtained in this work via a solution-based phase inversion approach. In the resulting PDI/CB/TPU cathodes, the mass ratios of the three components manifest profound influences on their composition, flexibility, conductivity and lithium storage behavior. The integrated PDI/CB/TPU cathode with optimized ratio can deliver impressive rate capability and good cycling stability in lithium ion batteries (LIBs). More importantly, the full LIBs with PDI/CB/TPU cathode and carbon cloth anode exhibit excellent electrochemical performances, which show no decay even at bending states, demonstrating the appealing prospects of the solution-processed organic cathodes in wearable secondary batteries. Obtained from a solution-based phase inversion approach, the flexible PDI/CB/TPU cathodes manifest excellent electrochemical performances and good mechanical stability in lithium ion batteries.

Preparation of Ge/N, S co-doped ordered mesoporous carbon composite and its long-term cycling performance of lithium-ion batteries

Abstract Germanium-based composites have been recognized as attractive candidates of anode materials for lithium-ion batteries (LIBs), on account of their high capacity properties, prominent ion diffusivity and high electronic conductibility. Nevertheless, similar to other alloy materials, the large volume expansion of germanium (Ge) presents during cycling, resulting in limited development of their practical application. Recently, co-doped heteroatom (e.g., N, S, B, and P) has been considered to be a promising strategy with the synergetic effect, the mesoporous carbon also shows advantage for enhancing electrochemical stability. Herein, we design an effective route to fabricate Ge nanoparticles confined within N, S co-doped ordered mesoporous carbon via nanocasting route. Benefited from the synergistic function of the ultra-small dispersed Ge nanoparticles and N, S co-doped mesoporous carbon matrix, the Ge/OMC-N-S delivers the outstanding lithium storage behaviour. As results, when used as an anode for LIBs, Ge/OMC-N-S exhibits a high reversible capacity of 1271 mA h g −1 after 200 cycles at a current density of 0.1 A g −1 , remarkable rate performance (623 mA h g −1 at 2.0 A g −1 ), and exceptional long-term cycling life (capacity of 641 mA h g −1 in 1000 cycles). Furthermore, we expect the potential of such an optimized configuration of carbon-encapsulating to enable the application of other alloy-type anodes.

Embedding CoMoO4 nanoparticles into porous electrospun carbon nanofibers towards superior lithium storage performance

CoMoO4 nanoparticles have been successfully in-situ formed and simultaneously embedded within the porous carbon nanofibers (CoMoO4/CNFs) via a facile electrospinning-annealing strategy. The porous CoMoO4/CNFs exhibit a specific surface area of 255.3 m2/g and a pore volume of 0.52 cc/g with average pore diameter of 43.5 nm. The carbon content in the CoMoO4/CNFs can be readily controlled by adjusting the annealing temperature. When examined as anode materials for lithium ion batteries (LIBs), the CoMoO4/CNFs demonstrate superior electrochemical performance, delivering a high reversible capacity of 802 mA h/g after 200 cycles at 200 mA/g and a high-rate capacity of 574 mA h/g at 2000 mA/g. The excellent lithium storage behavior can be attributed to the incorporation of CoMoO4 nanoparticles into the porous N-doped graphitic carbon nanofibers, which efficiently buffer the volume changes of CoMoO4 upon lithiation/delithiation and maintain the overall electrode conductivity/integrity.

Surface functionalized 3D carbon fiber boosts the lithium storage behaviour of transition metal oxide nanowires via strong electronic interaction and tunable adsorption energy

This work confirm that strong electronic interactions exists between Li-ion intercalation-based electrodes and 3D carbon-based current collectors, allowing shift in the p-adsorption energy level towards enhanced Li-ion storage performance.

Surfacing amorphous Ni-B nanoflakes on NiCo2O4 nanospheres as multifunctional bridges for promoting lithium storage behaviors.

Transition metal oxides (TMOs) have gained enormous research interests as negative materials of next generation lithium-ion batteries due to their higher energy density, lower cost, and better eco-friendliness. However, they are prone to low electronic conductivities and dramatic volume change during charge/discharge and there is also a great challenge in realizing TMO electrodes with satisfactory LIB performances. In this study, for the first time, amorphous nickel-boride (Ni-B) was introduced into porous NiCo2O4 nanospheres by an in situ solution growth route to overcome the existing issues. The coated Ni-B component could not only function as anchors for NiCo2O4 nanospheres to suppress the severe volume expansion but could also act as effective electron-conducting bridges to promote fast electron/charge transfer. Furthermore, the existence of abundant mesopores centered at ∼6.5 nm in this composite could effectively suppress the severe volume variations in the lithiation/delithiation process. As expected, the NiCo2O4@Ni-B composites delivered a high reversible capacity of 1221 mA h g-1 at 0.2 A g-1 and 865 mA h g-1 at 0.5 A g-1 over 500 cycles; more impressively, at the high rate of 5 A g-1, a capacity of 648 mA h g-1 could be also obtained, showing its good rate capability. As a result, these results demonstrated an effective and facile way to design conversion-type negative electrode materials with superior lithium storage properties.

Unusual formation of hollow NiCoO2 sub-microspheres by oxygen functional group dominated thermally induced mass relocation towards efficient lithium storage

The unique oxygen functional group dominated thermally induced mass relocation strategy was first purposefully explored for controllable synthesis of uniform NiCoO2 hollow spheres with enhanced lithium-storage behaviors for LIBs.

N-doped-carbon coated Ni2P-Ni sheets anchored on graphene with superior energy storage behavior

Transition metal phosphides (TMPs) have been widely studied as electrode materials for supercapacitors and lithium-ion batteries due to their high electrochemical reaction activities. The practical application of TMPs was generally hampered by their low conductivity and large volume changes during electrochemical reactions. In this work, nitrogen-doped-carbon (NC) coated Ni2P-Ni hybrid sheets were fabricated and loaded into highly conductive graphene network, forming a Ni2P-Ni@NC@G composite. The highly conductive graphene, the NC coating layer, and the decorated Ni nanoparticles in combination offer continuous electron transport channels in the composite, resulting with facilitated electrode reaction kinetics and superior rate performance. Besides, the flexible graphene sheets and well-decorated Ni particles among Ni2P can effectively buffer the harmful stress during electrochemical reactions to maintain an integrated electrode structure. With these favorable features, the composite demonstrated superior capacitive and lithium storage behavior. As an electrode material for supercapacitors, the composite shows a remarkable capacitance of 2,335.5 F·g−1 at 1 A·g−1 and high capacitance retention of 86.4% after 2,000 cycles. Asymmetrical supercapacitors (ASCs) were also prepared with remarkable energy density of 53.125 Whk·g−1 and power density of 3,750 Whk·g−1. As an anode for lithium ion batteries, a high reversible capacity of 1,410 mAh·g−1 can be delivered at 0.2 A·g−1 after 200 cycles. Promising high rate capability was also demonstrated with a high discharge capacity of 750 mAh·g−1 at 8 A·g−1. This work shall pave the way for the production of other TMP materials for energy storage systems.

Lithium storage behavior of MoO3–P2O5 glass as cathode material for Li-ion batteries

Abstract MoO3-P2O5 glasses were prepared by a simple melt quenching method. XRD and DSC investigations confirmed the amorphous state of 60Mo-40P, 70Mo-30P and 75Mo-25P glass. Interestingly, HRTEM images revealed the inherent crystallization behavior in Mo enriched glass. The existing nanocrystals performed a synergetic effect with the glass matrix to relax the stress caused by Li ions insertion/extraction. As a result, 75Mo-25P glass with distinct nanocrystals showed excellent long cycling stability. The structural transition of MoO3-P2O5 glass and the valence change of Mo ions during cycling were discussed. Furthermore, CV and EIS measurements were performed to elucidate the difference of redox reaction, electrons transport and ions diffusion in 75Mo-25P glass and crystalline MoO3. This study provides an avenue to exploit new cathode materials with long cycling life for Li-ion batteries.

Pseudocapacitive Lithium Storage in Three‐Dimensional Cobalt‐Doped MnO/Nitrogen‐Doped Reduced Graphene Oxide Aerogels as High‐Rate Anode Material

AbstractStructural design and modification are effective measures to improve the lithium storage performance of electrode materials. Herein, three‐dimensional (3D) porous Co‐doped MnO/nitrogen‐doped reduced graphene oxide aerogels (Co−MnO/NG‐G) have been prepared by successive self‐assembly processes, including the self‐assembly nucleation of Co−MnO on GO in H2O/N,N‐Dimethylformamide (DMF) mixed solvent, and the 3D reduction‐assembly of hydrogels accompanied with nucleation‐inducing growth of Co−MnO nanocrystals. Due to high‐efficient electron/ion transport channels dating from the novel 3D porous microstructure and improved electron/ion conductivity deriving from doping MnO with Co, the 3D Co−MnO/NG‐G electrode demonstrates high pseudocapacitive lithium storage behavior with 88.3 % at 2 mV s−1. As an anode in lithium‐ion battery, the 3D Co−MnO/NG‐G shows a high capacity of 982.8 mAh g−1 at 0.5 A g−1 after 100 cycles, outstanding rate capability with 424.0 mAh g−1 at 8 A g−1, as well as superior cycle stability with 508.9 mAh g−1 after 800 cycles at 4 A g−1. This work demonstrates that the synergistic strategy between cation doping and 3D porous channels for electron/ion transport is an effective way to design high‐rate anode materials.

Vacancy Associates Evoked Hematite Mesocubes with Enhanced Efficiency in Li Storage Behaviors

Vacancies can significantly determine the physical and chemical properties of inorganic materials, which play crucial roles in many areas of applications, such as electronics, catalysis, and energy storage devices. However, little is known about the relationships between vacancy feature and lithium (Li) storage behaviors of inorganic materials. Here, we discovered that the types and abundance of atom vacancies on anode materials strongly affect their Li storage performance. By comparing the Li storage performance between two hematite (α-Fe2O3) cubes with similar morphology but different predominant vacancies and applying the density functional theory computations on the Li-ion diffusion rate and substitution energy of Fe ions by Li ions, we show that the vacancies, in particular the large size vacancies on the surface of anode materials, could effectively reduce the barriers of Li-ion diffusion and decrease the substitution energy of Fe ions. This new finding may advance the design and development of nove...

Electrochemical potassium/lithium-ion intercalation into TiSe2: Kinetics and mechanism

Abstract As one promising candidate for next-generation energy storage systems, K-ion batteries (KIBs) attract increasing research attention due to the element abundance, low cost, and competent energy density as compared to Li-ion batteries. However, developing practical electrode materials in particular cathodes for KIBs is still in its infancy, and the related reaction mechanisms of the electrode materials are far from completely understood. In this work, TiSe2 was, for the first time, investigated as an intercalated-type electrode for potassium storage due to its large interlayer space. The potassiation/depotassiation reaction mechanism was unraveled based on the analysis of in-situ X-ray diffraction (XRD), ex-situ X-ray photoelectron spectroscopy (XPS), and ex-situ transmission electron microscope (TEM) results. Meanwhile, the lithium storage behaviour and the relevant lithiation/delithiation reaction mechanism were also studied in detail. The results reveal that K+ show lower diffusion coefficient and hence more sluggish intercalation reaction kinetics as compared with Li+. In addition, the intercalation reaction of K+ would cause irreversible structure changes, while the intercalation reaction is fully reversible for Li+ counterpart.

The Regulating Role of Carbon Nanotubes and Graphene in Lithium‐Ion and Lithium–Sulfur Batteries

The ever-increasing demands for batteries with high energy densities to power the portable electronics with increased power consumption and to advance vehicle electrification and grid energy storage have propelled lithium battery technology to a position of tremendous importance. Carbon nanotubes (CNTs) and graphene, known with many appealing properties, are investigated intensely for improving the performance of lithium-ion (Li-ion) and lithium-sulfur (Li-S) batteries. However, a general and objective understanding of their actual role in Li-ion and Li-S batteries is lacking. It is recognized that CNTs and graphene are not appropriate active lithium storage materials, but are more like a regulator: they do not electrochemically react with lithium ions and electrons, but serve to regulate the lithium storage behavior of a specific electroactive material and increase the range of applications of a lithium battery. First, metrics for the evaluation of lithium batteries are discussed, based on which the regulating role of CNTs and graphene in Li-ion and Li-S batteries is comprehensively considered from fundamental electrochemical reactions to electrode structure and integral cell design. Finally, perspectives on how CNTs and graphene can further contribute to the development of lithium batteries are presented.