Enhanced Lithium Ion Storage Research Articles

Exfoliation and restacking route to Keggin-Al13-treated layered ruthenium oxide for enhanced lithium ion storage performance

Ruthenium oxide nanosheets were used as hosts for the Keggin-Al13. The synthesized AR-150 has stable cycling performance as an anode material for lithium-ion batteries.

Regulating surface condition of cotton-derived carbon towards enhanced lithium ion storage behavior

With the advancement of battery technology, graphite as a negative electrode material for commercial lithium-ion batteries (LiBs) is reaching the limit of its capacity, and mesoporous carbon with a larger capacity is regarded as its best alternative. In this paper, waste cotton is used as the carbon source, and KOH and urea are used as pore formers and pore size regulators to prepare uniform mesoporous materials (N-PCC800) with a pore size distribution of 2–5 nm. Compared with the traditional KOH pore-making method, the addition of urea can adjust the pore size upward, thereby increasing the effective number of pores for Li+ insertion. While optimizing the structure, urea can also be used as an additional nitrogen source for the material to enrich the content of heteroatoms and defects, thereby increasing the amount of Li+ adsorbed by porous carbon. As an anode material, N-PCC800 exhibits a stable discharge capacity (1086 mAh g−1 at 100 mA g−1) far exceeding that of graphite. At a current density of 1000 mA g−1, there is still a capacity of 596 mAh g−1 remaining after 1000 cycles, indicating its advantages in rate performance and cycle performance. The optimized pore size and higher nitrogen content endow the carbon material with higher Li+ storage performance, and further kinetic analysis indicates that the increased capacity comes from the increased Li+ insertion. This work proposes a new pore size optimization scheme to obtain high-capacity mesoporous carbon, which provides an effective scheme for the reuse of waste cotton and cotton products and helps achieve the goal of carbon neutrality.

Insights into the enhanced Lithium-Ion storage performance of CoSx/Carbon polyhedron hybrid anode

In this work, the 3D cobalt sulfide/carbon polyhedral (CoSx/CP) hybrids (x = 1, 2) have been fancily prepared by employing the ZIF-67 as template. The as-prepared CoSx/CP inherit the structure of ZIF-67, realizing the polyhedral structure where the CoSx nanoparticles are well embedded. The battery performance measurements demonstrate that the CoS2 has played a significant role contributing to the lithium ions batteries (LIBs) performance of CoSx/CP. As a result, the capacity of the optimized CoSx/CP is 562 mAh g−1 after 300 cycles at 0.5 A g−1. When cycled at 10 A g−1, it delivers a reversible specific capacity of 131 mAh g−1. The electrochemical analysis points out that the optimized CoSx/CP possesses diverse electrochemical reactions and the lowest charge transfer resistance. Moreover, the insertion mechanism and structural evolution process of CoSx/CP are examined by the in-situ XRD. Beyond that, the unique nanoarchitecture of CoSx/CP guarantees the high specific surface area which enables the large electrode–electrolyte contract area, fast ions diffusion/electron transfer and robust structural stability. Meanwhile, the carbon skeleton is deductive to confine the huge volume expansion of CoSx as well.

Coaxial MWNTs@MnCo2O4 wrapped in conducting graphene for enhanced lithium ion storage

Coaxial MWNTs@MnCo2O4 wrapped in conducting graphene for enhanced lithium ion storage

Enabling Enhanced Lithium Ion Storage Performance of Graphdiyne by Doping with Group-15 Elements: A First-Principles Study.

As a typical two-dimensional material possessing sp and sp2 hybrid orbitals, graphdiyne (GDY) and its derivatives have been proposed as an attractive candidate for high-performance lithium ion batteries (LIBs). In this work, an advanced GDY LIB electrode is designed by doping with group-15 elements. With the aid of first-principles simulations, the geometric properties, electronic structures, theoretical storage capacities, open-circuit voltages, and diffusion path of Li atoms on doped GDY are comprehensively investigated. Specifically, 14 different adsorption sites are proposed, most of which are situated out of plane of the carbon network, resulting from the out of plane Pz orbitals of conduction band minimum and valence band maximum. Among the five doped GDY, phosphorus-doped graphdiyne (P-GDY) exhibits prominent lithium ion storage behavior, i.e., the maximum theoretical capacity is 1949 mA·h·g–1, which is ∼2.6 times higher than that of GDY. Moreover, calculation results in terms of the in-plane migration of lithium ion on P-GDY indicate that Li atoms prefer to diffuse across the carbon network (with a moderate barrier of 0.46 eV) rather than directly through the middle of the hexagonal aperture (with a higher barrier of 1.78 eV). Thus, this approach provides novel insights into the Li ion storage properties of group-15 element-doped GDY from the prospect of theoretical calculations, which would be useful to guide the future design of high-capacity GDY anodes for LIBs.

In situ one–pot synthesis of Sn/lignite–based porous carbon composite for enhanced lithium storage

To expand the variety of Sn/C composites, lignite–based porous carbon was initially prepared with Baoqing lignite as the raw material and K2CO3 as the extractant and activator. A novel Sn/lignite–based porous carbon composite was subsequently fabricated via an in situ one–pot synthesis method. In the nanocomposite, Sn nanoparticles are uniformly distributed on lignite–based porous carbon, improving the lithium–ion storage performance of the as–prepared material. Compared with pure Sn and bare lignite–based porous carbon, Sn/lignite–based porous carbon displayed a superior electrochemical performance. The composite material exhibits a high reversible capacity of 941 mAh g−1 after 200 cycles at 100 mA g−1. Even after 800 charge/discharge cycles at a high current density of 1000 mA g−1, the nanocomposite retains a reversible capacity of 573 mAh g−1. The enhanced lithium–ion storage performance can be attributed to the combined effect of Sn and lignite–based porous carbon.

Enhanced Lithium Ion Storage by Titanium Dioxide Addition to Zinc Telluride-Based Alloy Composites.

A nanostructured ZnTe-TiO₂-C composite is synthesized, via a two-step high-energy mechanical milling process, for use as a new promising anode material in Li-ion batteries (LIBs). X-ray diffraction and X-ray photoelectron spectroscopy results confirm the successful formation of ZnTe alloy and rutile TiO₂ phases in the composites using ZnO, Te, Ti, and C as the starting materials. Scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray spectroscopy mapping measurements further reveal that ZnTe and TiO₂ nanocrystals are uniformly dispersed in an amorphous carbon matrix. The electrochemical performances of ZnTe-TiO₂-C and other control samples were investigated. Compared to ZnTe-TiO₂ and ZnTe-C composites, the ZnTe- TiO₂-C nanocomposite exhibits better performance, thereby delivering a high reversible capacity of 561 mAh g-1 over 100 cycles and high rate capability at a high current density of 5 A g-1 (79% capacity retention of its capacity at 0.1 A g-1). Furthermore, the long-term cyclic performance of ZnTe-TiO₂-C at a current density of 0.5 A g-1 shows excellent reversible capacity of 528 mAh g-1 after 600 cycles. This improvement can be attributed to the presence of a TiO₂-C hybrid matrix, which acts as a buffering matrix that effectively mitigates the large volume changes of active ZnTe during repeated cycling. Overall, the ZnTe-TiO₂-C nanocomposite is a potential candidate for high-performance anode materials in LIBs.

Nano-silicon embedded in MOFs-derived nitrogen-doped carbon/cobalt/carbon nanotubes hybrid composite for enhanced lithium ion storage

Silicon has been deemed to be one of the most prospective anode material for lithium-ion batteries due to its high theoretical capacity, low lithiation potential, and bountiful resources. However, its industrial application can still be impeded by its unsatisfied electrochemical performance, especially poor cycling performance caused by larger volume expansion (about 300%). Herein, we synthesize the silicon-based composites by embedding nano-silicon in Co-based metal–organic frameworks derived nitrogen-doped carbon/cobalt/Co-catalyzed carbon nanotubes porous framework (Si@NC/Co/CNTs). In this architecture, the high conductivity NC/Co/CNTs framework with stable structure owing to the existence of Co can not only significantly improve the electrical conductivity to improve the reaction activity of Si, but also effectively buffer the volume expansion during electrochemical reaction. Hence, the advanced Si@NC/Co/CNTs exhibits a high reversible specific capacity (895 mAh g−1 at 0.1 A g−1) and excellent cycling performance (758 mAh g−1 after 800 cycles at 1 A g−1). Insight into the kinetics reveals that capacitive charge-storage mechanism plays an important role in boosting Li+ storage beneficial from the high specific surface area and accelerated charge transfer. This work propounds a simple route to prepare the Si/C hybrids with improved electrochemical performances for being of great application potential towards lithium-ion batteries anode.

Synthesis of a zinc ferrite effectively encapsulated by reduced graphene oxide composite anode material for high-rate lithium ion storage

Effectively immobilizing nano-sized electrochemical active materials with a 3D porous framework constituted by conductive graphene sheets brings in enhanced lithium ion storage properties. Herein, a reduced graphene oxide (RGO) supported zinc ferrite (ZnFe2O4) composite anode material (ZnFe2O4/RGO) is fabricated by a simple and effective method. Firstly, redox reaction takes place between the oxygen-containing functional groups on few-layered graphene oxide (GO) sheets and controlled quantity of metallic Zn atoms. ZnO nanoparticles are in-situ nucleated and directly grow on GO sheets. Secondly, the GO sheets are completely reduced by abundant Fe atoms, and corresponding γ-Fe2O3 nanoparticles are formed neighboring the ZnO nanoparticles. In this step, 3D porous RGO supporting framework are constructed with γ-Fe2O3@ZnO nanoparticles effectively encapsulated between the RGO layers. Finally, the well-designed γ-Fe2O3@ZnO/RGO intermediate product undergoes a thermal treatment to allow a solid-state reaction and obtains the ZnFe2O4/RGO composite. At a high current rate of 1.0 A·g−1, the ZnFe2O4/RGO composite exhibits an inspiring reversible capacity of 1022 mAh·g−1 for 500 consecutive cycles as anode material for lithium ion batteries. And the insight into the attractive lithium storage performance has been studied in this work.

Potassium Prussian blue-coated Li-rich cathode with enhanced lithium ion storage property

Abstract With high specific capacity, the layered Li-rich Mn-based oxide (LRMO) is a promising candidate cathode material for Li-ion batteries. However, the irreversible release of Li-ions during the first charging process, instability of LRMO/electrolyte interface and relatively low ion conductivity of LRMO result in low initial Coulombic efficiency (ICE), poor cycle stability and rate performance, which prohibit its further application. Interface engineering via additive coating is expected to effectively address these issues. Herein, we rely on potassium Prussian blue (KPB), a Li+ acceptor with good ion conductivity, as a new coating material on LRMO particles. The KPB coating not only forms a protective layer on the surface of LRMO against electrolyte corrosion, but also functions as a host for Li+ transport and accommodation, leading to enhanced ion conductivity and ICE of LRMO cathode. Consequently, 2 wt% KPB coated LRMO cathode achieved an initial discharge capacity of up to 281.7 mA h g−1 with an ICE of 85.69% compared to an ICE of 79.52% for the LRMO cathode without coating. The cycling and rate performance are also greatly improved as evidenced by the well maintained capacity of up to 176.8 mA h g−1 after 100 cycles at a current density of 0.5 C, compared to the limited capacity of only 135.3 mA h g−1 for the LRMO cathode without coating. This work pioneers the use of potassium Prussian blue as additive coating material to enhance performance of LRMO cathode, and we expect it to inspire the battery community with new strategies of material engineering/design toward practical application in high-energy lithium-ion batteries.

Fabrication of anatase TiO2/amorphous carbon nanoparticles as anode materials for enhanced lithium ion storage

A facile sol-gel method is used to fabricate anatase TiO2/amorphous carbon (a-TiO2/C) and pure a-TiO2 nanoparticles as anode materials in lithium-ion battery. In the a-TiO2/C hybrid, a-TiO2 is generated along with synthesis of amorphous carbon. Thus, a-TiO2 is uniformly embedded into amorphous carbon matrix, which showing a flake structure. The flakes are composed of a number of irregularly sized a-TiO2/C nanoparticles. Moreover, the flakes have porous channels. This designed structure suppresses the growth of a-TiO2 nanoparticles and accelerates the diffusion of lithium ions. Therefore, the hybrid materials exhibit an excellent rate and stability performance compared to pure a-TiO2 in electrochemical testing. The a-TiO2/C anode has discharge capacities of 293 mAh g−1 at 0.05 A g−1 and 172.6 mAh g−1 at 0.5 A g−1. Additionally, the a-TiO2/C anode retains a long cycling performance of 224.4 mAh g−1 at 0.2 A g−1 over 400 cycles with a capacity retention rate of 86.9%. An average capacity fading loss is 0.03275% per cycle, which is lower than 0.1335% of a-TiO2 anode per cycle (initial discharge capacity is 290.5 mAh g−1 and final discharge capacity is 135.4 mAh g−1). The results reveal that compounding of amorphous carbon effectively improves the electrochemical performance of a-TiO2.

Embedding Co9S8 nanoparticles into porous carbon foam with high flexibility and enhanced lithium ion storage

Co9S8 nanoparticles embedded in two dimensional/three dimensional (2D/3D) porous carbon foams are synthesized from carbonized melamine foam (CMF) @Co-ZIF-L. Due to the vertical-growth of 2D Co-ZIF-L on the carbonized 3D melamine foam wires, abundant meso- and macropores are formed among Co-ZIF-L nanosheets with sufficient micropores created from the carbonization of ZIF-L; thus 2D/3D carbon foam with hierarchical pores can be obtained. Meanwhile, Co9S8 nanoparticles are formed and uniformly dispersed into porous carbon, and such carbon wrapping can effectively alleviate the volume expansion of metal sulfide; thus high electrochemical performance can be achieved. For example, the specific capacity is as high as 615 mAh g−1 at 500 mA g−1 after 450 cycles, much higher than that of pristine CMF (79.5 mAh g−1). Moreover, due to the excellent flexibility of carbonized melamine foam, such composite can be directly used as free-standing binder-free electrode for lithium ion batteries, which exhibits great potential to be used in wearable electronics.

Enhanced lithium ion storage in dual carbon decorated β-Ga2O3 rendered by improved reaction kinetics

Graphene and amorphous carbon decorated β-Ga2O3 nanoparticles (β-Ga2O3@G/C) were fabricated via facile freezing-dry approach and subsequent sintering treatment. In the β-Ga2O3@G/C, β-Ga2O3 nanoparticles facilitate the lithium ion diffusion, and dual carbon decoration promotes the electron transfer, triggering high pseudocapacitive contribution for charge storage. The pseudocapacitive charge storage for the fresh electrode is 61.7%, reaching 62.5% after 50 cycles, and 66.7% after 100 cycles. Stable pseudocapacitive charge storage also leads to improved cyclability. The β-Ga2O3@G/C electrode exhibits high charge/discharge capacity of 517.9 and 521.8 mAh g−1 after 100 cycles at 0.2 A g−1, and 376.7/379.9 mAh g−1 after 150 cycles at 0.5 A g−1, respectively.

Co-N-C in porous carbon with enhanced lithium ion storage properties

Carbon materials as promising anodes for lithium ion batteries (LIBs) have attracted great attentions owing to their high theoretical capacities and rich natural resources. To improve anode performance of carbon, several common strategies have been developed, such as the fabrication of carbon with various nanostructures and modification of carbon frameworks by heteroatoms doping. Besides, the introduction of transition metal single atom or atom clusters embedded in nitrogen-doped carbon frameworks is also a feasible route. Herein, we report a simple and effective approach for synthesis of Con@N-C hybrids (i.e., Co@N-C-0, Con@N-C-1 and Con@N-C-2) with interconnected porous carbon nanostructures and numerous active sites (e.g., Co-N-C). When it was measured as anode for LIBs, the Con@N-C-1 hybrid displayed outstanding lithium storage properties with a high initial reversible capacity of 1587 mAh g−1 at 0.1 C and maintained a high reversible capacity of 1000 mAh g−1 at 5 C after 800 cycles. Both experimental and theoretical results reveal that Co-N-C with high specific activity along with interconnected porous carbon nanostructures synergistically promote the transportation and storage of Li+.

Nanoscopically and uniformly distributed SnO2@TiO2/C composite with highly mesoporous structure and bichemical bonds for enhanced lithium ion storage performances

A superior nanoarchitecture with vast phase boundaries interconnected via chemical bonds between carbon and ultrasmall nanocrystals shows enhanced Li+ storage performances.

Conventional synthesis of V2O5/graphite composites with enhanced lithium ion storage

For the sake of seeking appropriate electrodes for Lithium ion battery which can be further extended for mass production. In this research, ball milling procedure has been utilized to synthesize V2O5/graphite electrode. The ratio of each phase in the composite can be easily manipulated. Meanwhile, SEM images demonstrated that homogeneous microstructure has been achieved with these different compositions. Specifically speaking, an optimal performance utilized as cathode material for lithium ion battery had been realized with 7.5V2O5/graphite, which maintains a specific capacity of 136 mAh g−1 after 150 cycles under the current density of 50 mAh g−1. Moreover, a relative high specific capacity of 113.3 mAh g−1 (at the current density of 1A g−1) can be retained after 300 cycles. In addition to enhanced cycling stability, the improved rate capability had also been achieved in this composition. Further investigation of CV results revealed that a capacitive behavior contributed by the introduction of graphite was responsible for this enhancement. Here designated composite exhibits great potential in electrochemical field.

Honeycomb‐Inspired Heterogeneous Bimetallic Co–Mo Oxide Nanoarchitectures for High‐Rate Electrochemical Lithium Storage

AbstractNanostructure engineering has been proved to be an efficient approach for improving electrochemical properties for energy storage by accommodating volume changes, facilitating rapid mass transport paths, and enlarging ion storage sites and interfaces. The well‐designed fine nanostructures, unfortunately, are usually destroyed during long‐term cycles and ultimately lose their structural advantages. Herein, stimulated by the extraordinary structural stability, robust mechanical properties, and salient ventilation capacity of natural honeycomb species, bioinspired heterogeneous bimetallic Co–Mo oxide (CoMoOx) nanoarchitectures assembled from 2D nanounits are successfully fabricated via a molybdenum‐mediated self‐assembly strategy for improving the rate capability of electrochemical lithium storage devices. Owing to the robust structural stability and the ultrathin 2D wall structure, CoMoOx nanostructures present well‐maintained honeycomb‐like structure, rapid capacitive insertion–desertion behaviors, and thus significantly enhanced lithium ion storage performance at high rates (5.0 A g−1). It is also revealed that the reversible transition of cobalt and molybdenum phases closely associated with the ultrathin 2D wall structures greatly contribute to the outstanding electrochemical lithium storage performances. This attractive integration of structural and functional advantages achieved by learning from nature offers new insights into the design of cost‐effective electrode materials for high‐performance energy devices.

Reversible intercalation and exfoliation of layered covalent triazine frameworks for enhanced lithium ion storage.

We report that layered covalent triazine frameworks (CTF-1) can be rapidly and reversibly intercalated with either an oxidizing or a non-oxidizing acid based on the acid-base driven mechanism. The obtained CTF-1 intercalated compounds can be readily reacted with nitronium ions and spontaneously exfoliated into 1-2 layered functionalized CTF-1 nanosheets (f-CTF-1) with a high yield of 42%. The f-CTF-1 shows a 2.5 to 3.8 times increase in specific capacitance and much better rate performance when used as an LIB anode.

Tubular hierarchical structure composed of O-doped ultrathin MoS2 nanosheets grown on carbon microtubes with enhanced lithium ion storage properties

As one of the promising anodes for lithium ion battery, MoS2 is attracting widespread attention because of its high abundance, low cost, and high theoretical capacity. In this work, a designed robust structure of ultrathin O-doped MoS2 nanosheets with expanded interlayer spacing in situ grown on the carbon microtubes is proposed and investigated as high efficient anode material. The designed composite ensures multiple advantages, including enhanced electronic and ionic conductivity, short diffusion distance for lithium ions, and large electrode/electrolyte interface for rapid charge transfer reaction. Due to the unique features, the manufactured electrodes exhibit a high specific capacity of 970 mAh g−1 at 100 mA g−1, outstanding rate capability, and ultralong cycle life up to 2000 cycles at 1000 mA g−1.

Superior full-cell cycling and rate performance achieved by carbon coated hollow Fe3O4 nanoellipsoids for lithium ion battery

Iron oxide, a promising anode material for lithium ion batteries, has a high theoretical specific capacity but exhibits poor cycling performance and rate capability. To resolve these issues, 150 nm sized carbon coated, hollow Fe3O4 nanoellipsoids are designed in this study. Owing to the relatively high utilization ratio of Fe3O4 and the buffer provided by the carbon layer, this composite has enhanced lithium ion storage properties and long cycle life. From half-cell measurements, the capacity is found to be in excess of 400 mAh g−1 even after 1000 cycles at 5 A g−1. And then, a facile and practical strategy is used to gain a relatively high compressed density (∼1.87 g cm−3), so the volumetric capacity of the Fe3O4@C electrode can be further enhanced by subjecting it to compression. In the full cell test, the Fe3O4@C electrode has a specific capacity of 400 mAh g−1 and volumetric capacity of 749 mAh cm−3 after 100 cycles. The improvement in cycling stability can be attributed to minimal volume expansion and the stability of the solid-electrolyte interphase (SEI) layer, over the nanoparticles. Finally, the evolution of solid-electrolyte interphase layer is indirectly monitored and the progressive loss of active lithium is quantitatively measured.