Advanced Lithium-ion Battery Anode Research Articles

High lithium storage of SnO2/Sn@C enabled by a facile, efficient dual-porous architecture

SnO2 with a high theoretical capacity has been regarded as a promising candidate for new-generation lithium-ion battery anodes, but challenging as well for the big volumetric variation and poor intrinsic conductivity. To address this challenge, herein, the SnO2 particles containing a small amount of Sn are reduced to the nanoscale and confined in a dual-porous carbon matrix by a relatively facile strategy, and hence exhibits significantly improved electrochemical performance. It is demonstrated that the synergistic effects of SnO2/Sn nanoparticles and dual-porous carbon matrix contribute to fast electrochemical kinetics and enhanced structural stability of the as-prepared SnO2-based composite (SnO2/Sn@p-C). In particular, the dual-porous carbon matrix with two sizes of pores can not only efficiently accommodate the volumetric variation and prevent the aggregation and pulverization of the SnO2/Sn nanoparticles with its big pore confining function, but also promote the ion diffusion and electron transfer by its small pores constructed network conducting open tunnel-like structure. Consequently, the SnO2/Sn@p-C exhibits outstanding lithium storage properties, revealing high capacity of 917.7 mA h g−1 at 200 mA g−1 after 450 cycles as well as 628.9 mA h g−1 at 1000 mA g−1 after 1000 cycles. Thus high-performance makes SnO2/Sn@p-C a promising advanced lithium-ion battery anode.

Honeycomb-like 3D carbon skeletons with embedded phosphorus-rich phosphide nanoparticles as advanced anodes for lithium-ion batteries.

Phosphorus-rich iron phosphides (FeP2) have been regarded as excellent anode candidates for lithium storage owing to their low cost, high natural abundance, high theoretical capacity, and reasonable redox potential. However, FeP2 suffers from a few challenging problems such as low reversibility, fast capacity degradation, and big volume variation. Herein, we have designed and synthesized a 3D honeycomb-like carbon skeleton with embedded FeP2 nanoparticles (denoted as FeP2 NPs@CK), which can significantly promote the kinetics and maintain the structural stability during the cycling, resulting in an excellent electrochemical performance reflected by high reversibility and long-term cycling stability. FeP2 NPs@CK shows high reversibility, delivering a reversible capacity as high as 938 mA h g-1 at 0.5 A g-1. It also shows excellent cycling stability, delivering a capacity of 620 mA h g-1 after 500 cycles at 1 A g-1. Moreover, the fast kinetics and lithium storage mechanism of FeP2 NPs@CK are investigated by quantitative analysis and in situ X-ray diffraction. Such superior performance demonstrates that FeP2 NPs@CK could be a promising and attractive anode candidate for lithium storage.

In situ growth of CoO nanosheets on a carbon fiber derived from corn cellulose as an advanced hybrid anode for lithium-ion batteries

A facile method is proposed to prepare CoO/carbon fiber (CoO/CF) hybrids by employing corn cellulose as the biocarbon source for high-performance lithium ion batteries.

Boosting lithium storage of manganese oxides by integrating improved kinetics porous carbon coating and one-dimensional porous nanostructure

Achievement of improvement in structural stability and electrochemical kinetics is crucial for developing advanced manganese oxide-based anodes for lithium-ion batteries. Herein, a MnxOy@PC composite composed of well-defined one-dimensional porous Mn3O4/MnO hybrid nanowires coated by a porous carbon layer is fabricated for the first time and hence this composite intelligently integrates the structural advantages of one-dimension, porous structure and improved kinetics carbon coating. As expected, the results demonstrate that the structural stability and electrochemical kinetics of the MnxOy are improved significantly by the well-designed structure integration strategy. Namely, the combinatorial architecture of one-dimensional porous nanostructure and porous conductive carbon coating contributes to not only superior structure stability but also enhanced electrochemical kinetics of MnxOy@PC. Consequently, the MnxOy@PC reveals outstanding lithium storage performance with a high capacity of 798.4 mAh g−1 after 200 cycles at 200 mA g−1 as well as 518.3 mAh g−1 after 500 cycles at 1000 mA g−1. This work may open an efficient pathway to boost the performance of other promising nanostructured metal oxide anodes for lithium-ion batteries.

Hybrid MnO-SiOx@C microspheres with a hierarchical mesoporous structure for advanced lithium-ion battery anodes

A novel porous structure MnO-SiOx @C composite has been designed and prepared as an anode material for lithium-ion batteries through scalable spray pyrolysis and a subsequent annealing process. XRD, SEM, TEM, Raman, and BET measurements indicate that the MnO-SiOx @C composite displays a spherical mesoporous structure with SiOx particles, embedded in the porous MnO structure combined with carbon coated on the surfaces. The enhanced electrochemical performance can be attributed to the mutual segregation of the heterogeneous oxides of MnO and SiOx during delithiation and the buffer composition region at the origin of uniform carbon layers and abundant nanopores. In addition, the new phase Mn2SiO4, which is formed in the MnO-SiOx @C composite after 800 ºC, can act as the joint between MnO and SiOx to restrain the strain force originating from the volume change during the charge and discharge process. As a result, the obtained MnO-SiOx @C composite exhibits significantly enhanced electrochemical performance in terms of high Coulombic efficiency, excellent rate capability and good cyclability.

Progress of Binder Structures in Silicon-Based Anodes for Advanced Lithium-Ion Batteries: A Mini Review.

Silicon (Si) has been counted as the most promising anode material for next-generation lithium-ion batteries, owing to its high theoretical specific capacity, safety, and high natural abundance. However, the commercial application of silicon anodes is hindered by its huge volume expansions, poor conductivity, and low coulombic efficiency. For the anode manufacture, binders play an important role of binding silicon materials, current collectors, and conductive agents, and the binder structure can significantly affect the mechanical durability, adhesion, ionic/electronic conductivities, and solid electrolyte interface (SEI) stability of the silicon anodes. Moreover, many cross-linked binders are effective in alleviating the volume expansions of silicon nanosized even microsized anodic materials along with maintaining the anode integrity and stable electrochemical performances. This mini review comprehensively summarizes various binders based on their structures, including the linear, branched, three-dimensional (3D) cross-linked, conductive polymer, and other hybrid binders. The mechanisms how various binder structures influence the performances of the silicon anodes, the limitations, and prospects of different hybrid binders are also discussed. This mini review can help in designing hybrid polymer binders and facilitating the practical application of silicon-based anodes with high electrochemical activity and long-term stability.

Insight into the effects of dislocations in nanoscale titanium niobium oxide (Ti2Nb14O39) anode for boosting lithium-ion storage

Defect engineering through induction of dislocations is an efficient strategy to design and develop an electrode material with enhanced electrochemical performance in energy storage technology. Yet, synthesis, comprehension, identification, and effect of dislocation in electrode materials for lithium-ion batteries (LIBs) are still elusive. Herein, we propose an ethanol-thermal method mediated with surfactant-template and subsequent annealing under air atmosphere to induce dislocation into titanium niobium oxide (Ti2Nb14O39), resultant nanoscale-dislocated-Ti2Nb14O39 (Nano-dl-TNO). High-resolution transmission electron microscope (HRTEM), fast Fourier transform (FFT), and Geometrical phase analysis (GPA) denote that the high dislocation density engraved with stacking faults forms into the Ti2Nb14O39 lattice. The presence of dislocation could offer an additional active site for lithium-ion storage and tune the electrical and ionic properties of the Ti2Nb14O39. The resultant Nano-dl-TNO delivers superior rate capability, high specific capacity, better cycling stability, and making Ti2Nb14O39 a suitable candidate among fast-charging anode materials for lithium-ion batteries. Moreover, In-situ High-resolution transmission electron microscope (HRTEM) and Geometrical phase analysis (GPA) evinces that the removal of the dislocated area in the Nano-dl-TNO leads to the contraction of the lattice, alleviation of the total volume expansion, causing the symmetrization and preserves structural stability. The present findings and designed approach reveal the rose-colored perspective of dislocation engineering into mixed transition metal oxides as next-generation anodes for advanced lithium-ion batteries and all-solid-state lithium-ion batteries.

Efficient regeneration and reutilization of degraded graphite as advanced anode for lithium-ion batteries

As a burgeoning solid waste, it is of great significance for spent lithium-ion batteries (LIBs) that recovering graphite anode and valuable lithium simultaneously to achieve resource utilization and environmental protection. However, two major troubles, difficult separation and degraded structure, have stagnated the recycling of spent graphite anode. Hence, we propose an approach to achieve the separation of collector/graphite and structural restoration of graphite anode synchronously. Benefited from the acidity and oxidability of ammonium persulfate, the recovered graphite with enlarged layer spacing is successfully obtained. When assembled in coin-cell, it exhibits excellent lithium storage performance with high reversible capacity (365.3 mA h g−1 after 100 cycles at 0.03 A g−1) and long cyclic life (330.2 mA h g−1 after 500 cycles at 0.3 A g−1), which is apparently higher than that of spent graphite and closed to that of commercial graphite. Furthermore, renewed graphite anode also demonstrates negligible difference with commercial graphite in electrochemical performance for full-cells, manifesting the sustainable meritoriousness of this recycling process. This recycling approach with the advantages of green, efficiency, and conciseness has the application prospects for industrial recycling of graphite anode of spent LIBs.

Porous carbon with carbon nanotube scaffold for embedding Cu2O/Cu nanoparticles towards high lithium storage

Herein, it is demonstrated that the lithium storage performance of Cu2O electrode has been significantly upgraded by fabricating embedment of porous carbon (PC) with carbon nanotube (CNT) scaffold successfully. It is found that the combined effect of high conductive CNT and flexibly spongy porous carbon plays critical role in improving the electrochemical performance of Cu2O electrode for lithium-ion batteries, which efficiently upgrades not only the structural stability but also the conductivity of whole electrode. As a result, this Cu2O-based composite electrode shows outstanding cycling performance, high capacity and good rate capability, therefore exhibiting good promising for advanced lithium-ion battery anodes.

Sb2S3 nanorods/porous-carbon composite from natural stibnite ore as high-performance anode for lithium-ion batteries

To avoid the high purity reagents and high energy consumption involved in the manufacturing of lithium-ion battery anode materials, Sb2S3 nanorods/porous-carbon anode was prepared by remodeling natural stibnite ore with porous carbon matrix via a simple melting method. Due to the nanostructure of Sb2S3 nanorods and synergistic effect of porous carbon, the Sb2S3 nanorods/porous-carbon anode achieved high cyclic performance of 530.3 mA·h/g at a current density of 100 mA/g after 150 cycles, and exhibited a reversible capacity of 130.6 mA·h/g at a high current density of 5000 mA/g for 320 cycles. This shows a great possibility of utilizing Sb2S3 ore as raw material to fabricate promising anodes for advanced lithium-ion batteries.

Porous carbon assisted carbon nanotubes supporting Fe3O4 nanoparticles for improved lithium storage

Herein, to efficiently improve the lithium storage of Fe3O4 nanoparticles, a distinctive porous carbon (PC) assisted carbon nanotubes (CNTs) supporting architecture has been designed and fabricated successfully. The Fe3O4 nanoparticles are deposited on the surface of CNTs and then covered by an extra PC. In such a designed architecture, highly conductive and robust CNTs can not only improve the conductivity but also boost the structure of the as-fabricated Fe3O4-based composite (CNTs@Fe3O4@PC). In particular, the foam-like PC has a certain level of volume elasticity and open tunnel-like structure to better anchor the Fe3O4 nanoparticles on the surface of CNTs and facilitate the transfer of electrons and ions, therefore guaranteeing the fast kinetics and long-term stability. The results show that the capacitive contribution is predominant in lithium storage of the CNTs@Fe3O4@PC electrode. Consequently, the as-fabricated CNTs@Fe3O4@PC shows high capacity, good rate capability, and long life, displaying 766 and 572 mAh g-1 after 400 and 700 cycles at 200 and even 1000 mA g-1, respectively. Thus outstanding performance makes the CNTs@Fe3O4@PC have great potential to be advanced lithium-ion battery anode materials. Furthermore, this strategy can be extended to other nanostructured metal oxide anodes, such as CoO, SnO2, and Bi2O3 nanomaterials.

Stabilizing Co3O4 nanorods/N-doped graphene as advanced anode for lithium-ion batteries

Stabilizing Co3O4 nanorods/N-doped graphene as advanced anode for lithium-ion batteries

Three-dimensional hierarchical urchin-like Nb2O5 microspheres wrapped with N-doped carbon: An advanced anode for lithium-ion batteries

Orthorhombic Nb2O5 is a promising material for the anodes of lithium-ion batteries (LIBs) owing to its pseudocapacitive features, stability, and safety. However, the practical applications for Nb2O5 are limited due to its poor electrical conductivity. In this work, three-dimensional (3D) urchin-like microspheres coated with N-doped carbon were synthesized by hydrothermal synthesis and then polymerized in dopamine. When evaluated as anode for LIBs, the 3D urchin-like Nb2O5@N-C composites exhibited excellent high-rate capability (146 mAh g−1 at 20 C) and stability (78 mAh g−1 at 10 C after 2900 cycles). The remarkable electrochemical performance of the Nb2O5@N-C composites was ascribed to their unique structure and the N-doped carbon coating, which prevents the electrode from structural damage, mitigates volume expansion during the charge/discharge process, and enhances the conductance of the active material.

Ordered mesoporous carbon with tubular framework supported SnO2 nanoparticles intertwined in MoS2 nanosheets as an anode for advanced lithium-ion batteries with outstanding performances

A new nanocomposite based on three-dimensional ordered mesoporous carbon (OMC) with tubular framework supported SnO2 nanoparticles entangled in MoS2 nanosheets is developed ingeniously by nanocasting and hydrothermal methods. The bimodal mesoporous interconnected architecture of CMK-9 and MoS2 nanosheets host SnO2 nanoparticles inside the mesopores and interlayer regions. Herein, for the first time, electrochemical performances of SnO2/MoS2 heterojunction are explored with an OMC. The present architecture improves the diffusion of ions and conduction of charges, which assist in achieving outstanding capacity, superior rate capability and stable cycle life when the nanocomposite is employed as the anode for lithium-ion batteries (LIBs). Among the nanocomposites, the SnO2/MoS2(1:3)@CMK-9 anode delivers a large initial discharge capacity of 2211 mA h g−1 and an outstanding discharge capacity of 1245 mA h g−1 after 300 cycles with a capacity retention of 96% as compared to the 3rd cycle (1291 mA h g−1) at a current density of 100 mA g−1. At a current density of 1000 mA g−1, the anode provides an exceptional discharge capacity of 823 mA h g−1 after 1000 cycles with capacity retention of 91% as compared to the 3rd cycle. The present architecture of SnO2/MoS2(1:3)@CMK-9 nanocomposite anode with excellent electrochemical performances signifies its potential use in next generation LIBs.

Synthesis of defects and TiO2 co-enhanced Li4Ti5O12 by a simple solid-state method as advanced anode for lithium-ion batteries

High performance and low process cost are two contradictory issues, which limited the commercial application of Li4Ti5O12 (LTO). Here, defects and TiO2 co-enhanced LTO have been synthesized by a simple solid-state method. The crystal structure and morphology of the as-synthesized samples were characterized. The results show that the uniform nanoparticles with spinel structure contained defects and TiO2. Defects and TiO2 co-enhanced LTO shows outstanding reversible discharge capacity of 168.2 mAh g−1 at 1 C after 500 cycles. Further, it presents a stability discharge ability of 155 mAh g−1 at 55 °C at 1 C after 500 cycles. The advanced electrochemical performance could be attributed to the defects and TiO2 in LTO, which enhance conductivity and produce rich reaction interface, facilitating Li+ ion diffusion kinetics. The as-synthesized LTO shows high performance in conjunction with low process cost.

Scalable synthesis of silicon nanoplate-decorated graphite for advanced lithium-ion battery anodes.

A silicon nanoplate-decorated graphite design is developed for lithium battery anodes via a simple ball milling process. The resultant silicon-graphite electrodes show high cycling stability with high capacity, superior rate capability, and excellent electrode stability when compared to their counterparts, attributable to two-dimensional silicon and its area-to-area contact with graphite.

Construction of sandwich-type Co9S8-C anchored on carbonized melamine foam toward lithium-ion battery

Co9S8 nanoparticles (NPs) anchored on carbonized melamine foam with polydopamine derived carbon coating (CMF-Co9S8-C) was successfully constructed for advanced lithium-ion battery anode. The sandwich-type structure consists of massive Co9S8 NPs and dual N-doped carbon layers that not only accommodate the volume expansion effect but also shortens the transfer distance of Li+/e−. Moreover, the nanocomposite inherits 3D carbon network with hierarchical porous structure, which is beneficial for providing sufficient transport channels and contacting with electrolyte. With the prominent synergistic effects from structure and chemical properties, CMF-Co9S8-C hybrid compound exhibited high specific capacity of 645 mAh g−1 at 0.5 A g−1 after 200 cycles, and it delivered excellent cycling stability (520 mAh g−1) under a high current (2 A g−1) after 1000 cycles.

Enabling improved cycling stability of hollow SnO2/C composite anode for lithium-ion battery by constructing a built-in porous carbon support

Owing to the cooperative effect of well-defined interior voids and conductive and flexible carbon coating, the hollow nanostructural SnO2/C composites exhibit significantly improved electrochemical performance over their pure nanostructured SnO2 counterparts, and hence attracts increasing research interests. However, the potential collapse of SnO2 inwards interior voids and subsequent agglomeration will diminish the cycling stability of hollow SnO2/C composites and hence needs to be further improved. Herein, to reduce the excess void space and block agglomeration of the SnO2 inwards interior voids, a cubic hollow SnO2/C composite with a built-in porous carbon support yolk has been designed and constructed successfully. As a result, thus as-constructed composite with a novel architecture displays significantly improved cycling stability as comparison to the similar hollow SnO2@C composite without a built-in porous carbon, delivering 788 and 588 mAh g−1 at 200 and 1000 mA g−1 after 550 and even 900 cycles, respectively. The results obtained here could pave the way for properly improving the cycling stability of other hollow metal oxides/carbon composites for advanced lithium-ion battery anodes.

In-situ self-assembled hollow urchins F-Co-MOF on rGO as advanced anodes for lithium-ion and sodium-ion batteries

To obtain MOFs materials with good electrochemical performance in both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs), a kind of hollow urchins Co-MOF with doping fluorine (F) was in-situ assembled on reduced graphene oxide (rGO) using a simple solvothermal reaction. According to XRD, XPS and EDS mapping analysis, the molecular structure should be Co2[Fx(OH)1-x]2(C8O4H4) (denoted as F-Co-MOF). When the composite material is used as active material to assemble LIBs, it not only presents the outstanding reversible capacity (1202.0 mA h g−1 at 0.1 A g−1), but also gives the excellent rate performance and cycle performance (771.5 mA h g−1 at 2 A g−1 after 550 repeated cycles). The remarkable lithium storage capacity of F-Co-MOF/rGO is also reflected in the full cell, where it can still maintain a high capacity of 165.2 mA h g−1 after 300 cycles at 0.2 A g−1. It benefits from the synergistic effect of F-Co-MOF and high conductive rGO networks, so that the reversibility of lithium and sodium storage can be improved. This kind of F doped solvothermal synthesis of MOFs is of great significance for the exploration of high performance materials.

MOF-derived 3D hollow porous carbon/graphene composites for advanced lithium-ion battery anodes

MOF-derived 3D hollow porous carbon/graphene composites (HPCGCs) are fabricated through a facile solvent method with subsequent carbonization. In a typical synthesis process, hollow zeoliticimidazolate framework-8 (ZIF-8) nanoparticles are prepared on graphene oxide layers to set up a 3D structure. After carbonization, hollow porous carbon/graphene composites are synthesized, which serve as active materials in lithium-ion battery anodes and exhibit high specific capacity, promising cycling stability and rate capability. The superior performance is attributed to the synergistic effects between hollow carbon nanoparticles and graphene layers within the 3D structure of the composites, which enable fast transportation of both Li+ and electrons. The composites also have structural integrity to ensure stable long-time cycling. Consequently, the composites present a specific capacity of 849.5 ​mA ​h ​g−1 at 0.2 ​A ​g−1 after 200 cycles and of 403.1 ​mA ​h ​g−1 at 5 ​A ​g−1 after 1000 cycles in the cycling test. Besides, they present a specific capacity of 200.6 ​mA ​h ​g−1 at 10 ​A ​g−1 in the rate capability test.