Anode For Lithium Storage Research Articles

High-rate soft carbon anode for lithium storage: from modified pitch molecular structure to ordered carbon microcrystals

High-rate soft carbon anode for lithium storage: from modified pitch molecular structure to ordered carbon microcrystals

Preparation of Fe2O3 nanoparticles with ultrathin carbon covered as lithium storage anodes

This study focuses on the development of ultrathin carbon (UTC) treated with Fe2O3 nanoparticles as anode materials for lithium-ion batteries (LIBs). Here, a simple hydrothermal method has been adopted to prepare Fe2O3@C nanocomposite, followed by annealing. The obtained Fe2O3@C demonstrates Fe2O3 nanoparticles (NPs) with uniform carbon, which effectively mitigates volume expansion and enhances electrochemical performance. Encouraging, the first principal calculations ensure that carbon doping in Fe2O3 can notably reduce the band gap from 2.12 to 1.10 eV and enhance electronic conductivity.

Preparation of interconnected tin oxide nanoparticles on multi-layered MXene for lithium storage anodes

MXenes, a novel class of two-dimensional (2D) materials known for their excellent electronic conductivity and hydrophilicity, have emerged as promising candidates for lithium-ion battery anodes. This study presents a simple wet-chemical method for depositing interconnected SnO2 nanoparticles (NPs) onto MXene sheets. The SnO2 NPs act as both a high-capacity energy source and a spacer to prevent MXene sheets from restacking. The highly conductive MXene facilitates rapid electron and lithium-ion transport and mitigates the volume changes of SnO₂ during the lithiation/delithiation process by confining the SnO₂ NPs between the MXene layers. This composite anode, SnO2@MXene, leverages the high capacity of SnO2 and the structural and mechanical stability MXene provides. The SnO2@MXene anode exhibits superior electrochemical performance, with a high specific capacity of 678 mAh g− 1 at a current rate of 2.0 A g− 1 over 500 cycles, outperforming pristine MXenes and SnO2 nanoparticles.

Dramatic Enhancement Enabled by Introducing TiN into Bread-like Porous Si-Carbon Anodes for High-Performance and Safe Lithium Storage.

Doping modifications and surface coatings are effective methods to slow volume dilatation and boost the conductivity in silicon (Si) anodes for lithium-ion batteries (LIBs). Herein, using low-cost ferrosilicon from industrial production as the energy storage material, a bread-like nitrogen-doped carbon shell-coated porous Si embedded with the titanium nitride (TiN) nanoparticle composite (PSi/TiN@NC) was synthesized by simple ball milling, etching, and self-assembly growth processes. Remarkably, the porous Si structure formed by etching the FeSi2 phase in ferrosilicon alloys can provide buffer space for significant volume expansion during lithiation. Highly conductive and stable TiN particles can act as stress absorption sites for Si and improve the electronic conductivity of the material. Furthermore, the nitrogen-doped porous carbon shell further helps to sustain the structural stability of the electrode material and boost the migration rate of Li-ions. Benefiting from its unique synergistic effect of components, the PSi/TiN@NC anode exhibits a reversible discharge capacity up to 1324.2 mAh g-1 with a capacity retention rate of 91.5% after 100 cycles at 0.5 A g-1 (vs fourth discharge). Simultaneously, the electrode also delivers good rate performance and a stable discharge capacity of 923.6 mAh g-1 over 300 cycles. This research can offer a potential economic strategy for the development of high-performance and inexpensive Si-based anodes for LIBs.

CoO nanocrystals dispersed in N-doped carbon networks as enhanced anode for lithium storage

CoO emerges as a promising anode material for lithium-ion batteries (LIBs) because of high theoretical specific capacity and rich resource. However, its practical application is impeded by significant volume expansion and poor electrical conductivity during the charging and discharging cycles. Herein, we construct a nanocomposite of CoO nanocrystals and N-doped carbon serving as an enhanced anode for LIBs by a facile strategy. In the nanocomposite, CoO nanocrystals with average size of 60 nm uniformly were dispersed in N-doped carbon networks. The synergy effects of CoO nanocrystals and N-doped carbon networks can extremely enhance electronic conductivity, relieve volume expansion, and effectively protect CoO nanocrystals from aggregating. Hence, the composite anode delivers large reversible capacity (1190 mAh g−1 at 0.3 A g−1 after 100 cycles), remarkable rate capability (592 mAh g−1 at 5 A g−1), and long cycling ability. This offers a simple approach for designing high-performance anodes for LIBs.

Constructing stress-release layer on Si nanoparticles for high-performance lithium storage

Tailing structures of silicon anode to alleviate the mechanical stress has an important significance in the development of lithium-ion batteries (LIBs). Herein, the stress-released layer of N-doped cubic carbon on the surface of Si nanoparticles (Si@NCC) is explored to stabilize the electrode. Endowed with the unique superiority, the Si@NCC electrode delivers an impressive lithium storage performance with high specific capacity of 630 mAh/g at 0.1 A/g, excellent cycling stability (72.0 % capacity retention after 100 cycles at 0.1 A/g) and good rate capability (375 mAh/g at 2 A/g). It has been demonstrated that the N-doped cubic carbon shell with high conductivity can effectively limit the expansion and agglomeration of Si nanoparticles. Besides, the COMSOL simulations of the stress distributions in materials confirm that the N-doped cubic carbon layer could remarkably decrease the stress originated from the volume expansion of Si nanoparticles during the lithiation. Therefore, this work provides ideas for the mechanical effect of Si-based anodes for lithium storage and sheds lights on the designing advanced materials toward high-performance energy storage devices.

Oxygen vacancy modulated Ti2Nb10O29 anodes for high-rate lithium storage

Ti2Nb10O29 (TNO) is a prospective anode for lithium-ion batteries (LIBs) because of its high theoretical capacity, high energy density, and safer operating voltage. However, the lower conductivity and slower lithium-ion diffusion characteristic lead to performance degradation and accelerated capacity degradation. In this work, we developed a novel and simple urea-assisted heat treatment method to enrich oxygen vacancies in TNO anodes. Oxygen vacancy introduction leads to the formation of Ti3+ and Nb4+ and the optimization of electronic structure, which provide more active sites for ion insertion and accelerate electron transport and migration. The optimized sample (TNO-M) demonstrates excellent high-rate capacity and cyclic stability. Specifically, the reversible capacity is 155.4 mAh/g at 10C. A capacity retention ratio of 97.87 % can be maintained after 200 cycles at 1C. Even after 500 cycles at 5C, TNO-M can still deliver a high capacity of 156.4 mAh/g. The strategy of developing high-capacity and high-rate anodes provides a new inspiration for the applications of fast charging of energy-dense LIBs.

Three-Dimensional Carbon Nanotubes Buffering Interfacial Stress of the Silicon/Carbon Anodes for Long-Cycle Lithium Storage.

Silicon/graphite composites show a high specific capacity and improved cycling stability. However, the intrinsic difference between silicon and graphite, such as unequal volume expansion and lithium-ion diffusion kinetics, causes persistent stress at the silicon/graphite interface and the expansion of the electrical isolation region. Herein, carbon nanotubes (CNTs) were successfully introduced into silicon/carbon composites via ball milling and spray drying, which effectively relieved the stress concentration at the direct contact interface and formed a three-dimensional conductive structure. In addition, CNTs and amorphous carbon acting as "lubricants" further improved the inherent differences between silicon and graphite. As a result, the Si/CNTs/G@C-1 anode increased the cycling performance and rate capability, with a reversible capacity of up to 465 mAh g-1 after 500 cycles at 1 A g-1 and superior rate performance of 523 mAh g-1 at 2 A g-1. It is believed that this strategy may provide a feasible preparation of large-scale high-content silicon-based nanocomposite anodes in lithium-ion batteries.

Synergistic effect of carbon nanotube and encapsulated carbon layer enabling high-performance SnS2-based anode for lithium storage

Tin disulfide (SnS2), due to large interlayer spacing and high theoretical capacity, is regarded as a prospective anode material for lithium-ion batteries. Nevertheless, the poor electron conductivity of SnS2 and huge volumetric change during the lithiation/delithiation process lead to a rapid capacity decay of the battery, hindering its commercialization. To address these issues, herein, SnS2 is in-situ grown on the surface of carbon nanotubes (CNT) and then encapsulated with a layer of porous amorphous carbon (CNT/SnS2@C) by simple solvothermal and further carbonization treatment. The synergistic effect of CNT and porous carbon layer not only enhances the electrical conductivity of SnS2 but also limits the huge volumetric change to avoid the pulverization and detachment of SnS2. Density functional theory calculations show that CNT/SnS2@C has high Li+ adsorption and lithium storage capacity achieving high reaction kinetics. Consequently, cells with the CNT/SnS2@C anode exhibit a high lithium storage capacity of 837 mAh/g after 100 cycles at 0.1 A/g and retaining a capacity of 529.8 mAh/g under 1.0 A/g after 1000 cycles. This study provides a fundamental understanding of the electrochemical processes and beneficial guidance to design high-performance SnS2-based anodes for LIBs.

Lithium-conducting phosphates as artificial solid-electrolyte interphase on silicon anode for supreme lithium storage

Silicon (Si) anode is an ideal material for next-generation lithium-ion batteries due to its high specific capacity. Unfortunately, the fragmentation and reconstruction of solid electrolyte interface (SEI) film caused by volume expansion during the (de)lithiation is still a problem to be overcome. Constructing a stable SEI film on Si surface through interface engineering is a very effective strategy to improve the electrochemical performance. In this work, we construct lithium-conducting phosphates (Li3PO4, denoted as LPO) as SEI film and SiOx buffer layer on Si surface. The obtained Si@SiOx@LPO anode retains 2015 mAh g−1 after 100 cycles at 0.2 A g−1 with a capacity retention of 73.6%, and 1636 mAh g−1 after 500 cycles at 1 A g−1 with a capacity retention of 81.7%, which is significantly higher than the Si anode under the same conditions, respectively. In addition, in/ex-situ tests demonstrate that Si@SiOx@LPO anode has faster lithium-ion diffusion and structural reversibility. The analysis shows that LPO has higher mechanical strength and provides better ionic conductivity. On the other hand, SiOx buffer layer can not only reduce the volume expansion of Si, but also reduce the energy barrier between Si and LPO interface and increase the electrical conductivity. Therefore, this work provides a novel strategy for boosting electrochemical performance by artificial SEI and surface modification.

For regenerated graphite: Tailoring sub-surface architecture with strong pre-storage abilities towards high-rate properties

Captured by the economic value and environmental friendliness, the high-value recycling of spent batteries has been devoted plenty of attention. However, the regenerated graphite is still limited by large anisotropy and inferior rate abilities. Through the tailoring of low-temperature ionic liquid, the further regenerated graphite displayed rich sub-surface pores and improved crystalline degree, bringing about strong wettability and enhanced isotropy. Utilizing as lithium-storage anode, the optimized sample could deliver a capacity of 321 mAh/g after 300 loops at 1.0 C. Even at 2.0 C after 400 cycles, their capacity could also remain about 278 mAh/g. Supported by the detailed kinetic analysis, the abundant pores of sub-surface served significant roles in the enhancements of diffusion/surface-controlling behaviors. Their pre-storage advantages would be beneficial for the alleviation of voltage dropping, resulting in improved rate properties. Meanwhile, its activation energy was calculated at about 14.52 KJ mol−1, revealing its relatively small ion-diffusion energy barrier. More significantly, assisted by economic analysis, its revenue could also reach up to 5700$ t−1, with a promising recycling value. Given this, the work is expected to offer significant cooperative regeneration manners and shed light on the significant effect of sub-surface designing.

Dynamically Forming Interconnected Interfaces in Confined Heterostructures Enable High Capacity Conversion Chemistry

AbstractHeterostructures endow electrochemical hybrids with promising energy storage properties owing to synergistic effects and interfacial interaction. However, developing a facile but effective approach to maximize interface effects is crucial but challenging. Herein, a bimetallic selenide heterostructure is realized in a confined carbon network via an in situ electrochemical strategy to induce highly active and stable electrode architecture. The dynamically formed heterostructures upon repeated delithiation/lithiation process not only yield abundant interconnected SnSe2/FeSe2 heterojunctions with continuous channels for ion/electron transfer but maintain excellent conversion reversibility. Serving as anode for lithium storage, the SnSe2/FeSe2@C framework enables a high discharging capacity of 1781.9 mAh g−1 at 0.5 A g−1 after 500 cycles and superior cycling stability (no capacity fade after 1200 cycles at 2 A g−1). This study can guide future design protocols for interface engineering through the formation of dynamic channels of conversion reaction kinetics for potential applications in high‐performance electrodes.

Correction to: Electrochemical reconstruction: a new perspective on Sn metal–organic complex microbelts as robust anode for lithium storage

Correction to: Electrochemical reconstruction: a new perspective on Sn metal–organic complex microbelts as robust anode for lithium storage

A flexible plane-wire MoO2-anchored carbon nanofiber matrix as freestanding anodes for lithium storage with enhanced cyclability

Inspired by beds of silkworm cocoon, a flexible ″plane-wire″ MoO2-anchored carbon nanofiber matrix has been successfully prepared through electrospinning and subsequent annealing processes. It delivers an initial discharge capacity of 877 mAh g−1 at 200 mA g−1 with a high initial coulombic efficiency of 84.7 % and showcases a high reversible specific capacity of 743 mAh g−1 in the second cycle when employed as free-standing anodes for lithium batteries. It also exhibits good rate performance and superb cyclability, which delivering a specific capacity of 364 mAh g−1 at a high current density of 2 A g−1 and maintains a notable specific capacity of 674 mAh g−1 even after 2000 cycles. It is found that, the carbon nanofiber matrix serves as a robust electronic conductive network to reduce the charge transfer resistance and promote the transportation of Li+, and provides excellent support to buffer volume changes of the MoO2, resulting in enhanced rate performance and cyclability. Moreover, these electrodes are designed to be free-standing, which can improve the flexibility of the electrode and initial coulombic efficiency. It is believed that the as-prepared ″plane-wire″ MoO2-anchored carbon nanofiber matrix is a promising anode material for high-performance LIBs.

A facile preparation route of MnO@C composite for high lithium storage anode

High performance and easy preparation are equally important for the development of MnO anode. Herein, a facile preparation route is proposed to successfully prepare a high-performance MnO@C composite anode. The MnO@C comprises of nanosized MnO embedded within a porous carbon matrix. The findings determined by systematic study demonstrate that the porous carbon matrix not only improves structure stability but also enhances electrochemical kinetics of the nanosized MnO, ultimately resulting in outstanding electrochemical performance of the MnO@C anode for lithium-ion batteries, with 943.6 and 411.5 mAh/g after 270 and 500 cycles at 200 and 1000 mA g−1, respectively.

Ultrathin conjugated microporous thermoset nanosheets for efficient Li-ion storage

Ultrathin conjugated microporous thermoset nanosheets (CMT-n) was successfully synthesized based on a solvent-free, catalyst-free thermosetting process and CMT-n shows excellent discharge capacity and cycling stability as anodes for lithium storage.

Rational design of N-doped C-encapsulated flower-like nickel-based heterostructured microsphere anodes for high-capacity and stable lithium storage.

Designing a unique morphology and nanoarchitecture with a heterostructure is regarded as an efficient strategy to achieve lithium-ion batteries (LIBs) with high capacity and cycle life. Herein, N-doped C-encapsulated flower-like NiS/Ni3(BO3)2 heterostructures (NiS/Ni3(BO3)2/NC) with a core-shell morphology are successfully synthesized by a facile general method to improve the rate performance and prolong the cycle life of LIBs. The coated NC layer and core-shell structure with elasticity can relieve the volume expansion during the lithiation/delithiation process to strengthen the stability of the structure. Moreover, the NC layer and NiS/Ni3(BO3)2/NC heterostructure can enhance the electronic conductivity of the electrode and guarantee fast and unimpeded electron transfer channels, thereby improving the electrochemical reaction kinetics. Owing to the synergy of heterostructures and core-shell layer, the as-synthesized NiS/Ni3(BO3)2/NC anode acquires a specific charge capacity of 549 mA h g-1 at 0.2 A g-1 after 100 cycles; meanwhile, a reversible capacity of 322 mA h g-1 can be maintained even at 1 A g-1 after 500 cycles. This study develops a universal interface manipulation strategy for the synthesis of M3B2O6-based or/and other advanced transition metal compound anode materials for the practical applications of LIBs.

Controllable fabrication of FeCoS4 nanoparticles/S-doped bowl-shaped hollow carbon as efficient lithium storage anode

To address the low conductivity and easy agglomeration of transition metal sulfides nanoparticles, FeCoS4 nanoparticles embedded in S-doped hollow carbon (FeCoS4@S-HC) composites was successfully fabricated through a combination of hydrothermal process and sulfidation treatment. The unique bowl-shaped FeCoS4/S-HC composites exhibit excellent structural stability with high specific surface area of 303.7 m2·g–1 and pore volume of 0.93 cm3·g–1. When applied as anode material for lithium-ion batteries, the FeCoS4@S-HC anode exhibits efficient lithium storage with high reversible specific capacity (970.2 mA·h·g–1 at 100 mA·g–1) and enhanced cycling stability (574 mA·h·g–1 at 0.2 A·g–1 after 350 cycles, a capacity retention of 84%). The excellent lithium storage is attributed to that the bimetallic FeCoS4 nanoparticles with abundant active sites can accelerate the electrochemical reaction kinetics, the bowl-shaped S-HC structure can provide stable mechanical structure to suppress volume expansion.

CdS@C nanowires with rich sulfur vacancies for high-performance lithium storage anodes

CdS@C nanowires with rich sulfur vacancies for high-performance lithium storage anodes

A feasible recycling route for spent graphite: Microwave-assisted puffing with Fe2O3 loading to construct high-performance anode for lithium-ion batteries

Nowadays, one of the important issues associating with the lithium-ion battery industry is to address the inefficient utilization of spent graphite from plenty of spent batteries. Conventional methods including discarding or burning will exacerbate the environmental risks, which calls for novel routes to optimize the recycling of spent graphite. This study proposes a novel recycling strategy for spent graphite to construct Fe2O3@microwave-puffed graphite (Fe2O3@MPG) composite anode for high-capacity lithium storage. By means of mild intercalation followed by microwave treatment, spent graphite is converted to puffed graphite which can be used as framework for loading Fe2O3 to form Fe2O3@MPG with sandwich structure. This sandwich structure can provide conductive networks and channels to enhance conductivity and Li ions transfer, as well as confine Fe2O3 in microwave-puffed graphite framework to ease the structural instability caused by the volume change of Fe2O3, thereby endowing the Fe2O3@MPG composite with superior rate performance, high capacity, and excellent structural stability. The Fe2O3@MPG electrode possesses a specific capacity of 1100 mAh g−1 at 200 mA g−1, exhibits excellent rate performance with a capacity of 632 mAh g−1 at 2000 mA g−1, and delivers an outstanding cycling performance for 500 cycles. This study not only provides an important method for the efficient recycling of spent graphite but develops a universal method for modifying transition metal oxides anode utilizing spent graphite, thereby promoting the closed-loop lifecycle of graphite and the resource sustainability in the LIBs industry.