Performance Anodes For Lithium-ion Batteries Research Articles

Template-free synthesis of biomass-derived carbon coated Li4Ti5O12 microspheres as high performance anodes for lithium-ion batteries

The hierarchical Li4Ti5O12/C microspheres based on the waste biomass of phoenix tree leaf are synthesized as anodes for lithium-ion batteries. The phoenix tree leaf derived activated carbon (CPTL) are uniformly coated on the surface of acanthosphere-like Li4Ti5O12 (LTO) microspheres using a facial hydrothermal method to fabricate hierarchical porous structures with conductive interconnected 3D networks. Results show that the LTO-CPTL composite with 3 wt% carbon delivers the best electrochemical performance at both ambient and low temperatures with an initial discharge capacity of 212 mAh g−1 at 1 C and capacity retention of 95% after 500 cycles. The present study demonstrates a facile and cost-efficient way to fabricate high performance electrode materials for batteries.

K6Nb10.8O30 groove nanobelts as high performance lithium-ion battery anode towards long-life energy storage

Owing to the multiple redox couples of Nb5+/Nb4+ and Nb4+/Nb3+, Nb-based compounds have attracted great attention to be promising high-capacity anode materials for rechargeable batteries. Here, K6Nb10.8O30 groove nanobelts (GNB) are synthesized through heat-treating the adjustable electrospun potassium niobate nanofibers, thereupon the structural change in the lithiation and delithiation is evidently imaged via in situ transmission electron microscopy (TEM). From in situ observations, the K6Nb10.8O30 GNB, in virtue of its stability, is ascertained to be adopted as anode material in lithium-ion batteries (LIBs). Evaluated as lithium storage host, GNB outstrip nanowires (NW) in cyclicity and in reversible capacity. Even after 1000 cycles, the retention capacity of K6Nb10.8O30 GNB is as high as 69%. Furthermore, the lithium-storage mechanism is also investigated via in situ X-ray diffraction (XRD). It is proved that the phase transition takes place from Li-poor K6Nb10.8O30 phase to Li-rich Li22K6Nb10.8O30 phase via two steps. In addition, the results obtained from ex situ TEM and ex situ X-ray photoelectron spectroscopy (XPS) also prove that the behavior of lithiation and de-lithiation for K6Nb10.8O30 GNB is highly reversible, suggesting that it can be a possible anode material.

Ternary Composites Using Graphitic Carbon Nitride/Tin Disulfide/Reduced Graphene Oxide (mpg-C3N4/Sns2/RGO) for Visible Driven Photoelectrochemical Water Splitting

Photoelectrochemical (PEC) water splitting is the potent technology to solve the global issues of energy crisis and environmental pollution. It converts solar energy to chemical energy stored in the form of hydrogen. In practical application, no single material can meet all the requirements for PEC water splitting. Two-dimensional (2D) nanostructures have been developed as potential materials for application in photoelectrochemical (PEC) water splitting due to their unique structure and fascinating properties. However, the light harvesting ability of bulk or nanosized materials are always limited due to the low light transmittance and high reflection at the grain boundaries. Also, the photo generated charge carriers inside the semiconductor with atomistic thickness will reach the surface faster relative to bulk materials due to the shortened transport distance. SnS2 is a two-dimensional (2D) transition metal dichalcogenide with a layered cadmium iodide (CdI2) structure. It has a narrow band gap of 2.18-2.44 eV. It is inexpensive, nontoxic and chemically stable in acidic and neutral solutions. A metal free semiconductor, known as graphitic carbon nitride (g-C3N4) also possesses a layered 2D structure and has been reported to have potential applications in photocatalysis. It exhibits various interesting properties, including visible-light absorption with a band gap of 2.7 eV. However, g-C3N4 suffers from low electrical conductivity which can be enhanced by the use of reduced graphene oxide (RGO). RGO has been extensively used by combining with various semiconductors to develop efficient photocatalysts. In the present work, ternary composites consisting of 2D nanomaterials of SnS2, reduced graphene oxide (RGO), and mesoporous graphitic carbon nitride (mpg-C3N4) were synthesized by using hydrothermal method. The presence of SnS2, mpg-C3N4 and RGO was confirmed by XRD, UV-Vis spectroscopy, and TEM. The single SnS2 nanosheet acquires a hexagonal structure with a lateral size of 20-50 nm. Generally, these SnS2 nanosheets tend to agglomerate which is prevented by RGO nanosheets. Due to the intimate face-to-face interactions offered by the 2D structured constituents, the obtained composite showed excellent performance as photoanode. The ternary composite showed photocurrent density of 1.4 mA/cm 2 at 1.2 V versus RHE, which is over 28 times higher than that of the pure SnS2 material and almost 5 times more than C3N4-SnS2 composite. The superior photocatalytic activity of the mpg-C3N4/SnS2/RGO composite is attributed to enhanced separation of the photogenerated electron-hole pairs, as well as increased visible-light absorption. [1] J. Di, J. Xia, H. Li, Z. Liu, Freestanding atomically-thin two-dimensional materials beyond graphene meeting photocatalysis: Opportunities and challenges, Nano Energy. 35 (2017) 79-91. [2] Y. Sun, H. Cheng, S. Gao, Z. Sun, Q. Liu, Q. Leu, F. Lei, T. Yao, J. He, S. Wei, Y. Xie, Freestanding tin disulfide single-layers realizing efficient visible-light water splitting, Angew. Chemie - Int. Ed. 51 (2012) 8727-8731. [3] Z. Zhang, J. Huang, M. Zhang, Q. Yuan, B. Dong, Ultrathin hexagonal SnS2 nanosheets coupled with g-C3N4 nanosheets as 2D/2D heterojunction photocatalysts toward high photocatalytic activity, Appl. Catal. B Environ. 163 (2015) 298-305. [4] M.S.A. Sher Shah, A.R. Park, A. Rauf, S.H. Hong, Y. Choi, J. Park, J. Kim, W.-J. Kim, P.J. Yoo, Highly interdigitated and porous architected ternary composite of SnS2 , g-C3N4 , and reduced graphene oxide (rGO) as high performance lithium ion battery anodes, RSC Adv. 7 (2017) 3125-3135. Figure 1

Partially Etched Ti3 AlC2 as a Promising High-Capacity Lithium-Ion Battery Anode.

MXenes, a family of two-dimensional transition-metal carbide and nitride materials, are thought to be promising materials in energy storage because of their high electronic conductivity, hydrophilic surfaces, and low diffusion barriers. MXenes are generally prepared by removing the "A" elements (A=Al, Si, Sn, etc.) from their corresponding MAX phases by using hydrofluoric acid (HF) and other etching agents, although these "A" elements usually have great volumetric and gravimetric capacities. In a study of the etching progress of Ti3 AlC2 and evaluation of their anode performance in lithium-ion batteries, a partially etched sample (0.5 h-pe Ti3 C2 Tx ) is found to have much higher capacity (160 mAh g-1 , 331.6 mAh cm-3 at 1C) when compared with the fully etched Ti3 C2 Tx (110 mAh g-1 , 190.3 mAh cm-3 at 1C). Moreover, a 99 % capacity retention was observed even after 1000 cycles in the 0.5 h-pe Ti3 C2 Tx anode. This interesting result can be explained, at least in part, by the alloying of the residual Al during lithiation.

CoP nanoparticles enwrapped in N-doped carbon nanotubes for high performance lithium-ion battery anodes

CoP is a candidate lithiumstorage material for its high theoretical capacity. However, large volume variations during the cycling processes haunted its application. In this work, a four-step strategy was developed to synthesize N-doped carbon nanotubes wrapping CoP nanoparticles (CoP@N-CNTs). Integration of nanosized particles and hollow-doped CNTs render the as-prepared CoP@N-CNTs excellent cycling stability with a reversible charge capacity of 648 mA·h·g−1 at 0.2 C after 100 cycles. The present strategy has potential application in the synthesis of phosphide enwrapped in carbon nanotube composites which have potential application in lithium-ion storage and energy conversion.

A facile synthesis of heteroatom-doped carbon framework anchored with TiO2 nanoparticles for high performance lithium ion battery anodes

Titanium dioxide (TiO2)-based materials have been well studied because of the high safety and excellent cycling performance when employed as anode materials for lithium ion batteries (LIBs), whereas, the relatively low theoretical capacity (only 335 mAh g−1) and serious kinetic problems such as poor electrical conductivity (~ 10−13S cm−1) and low lithium diffusion coefficient (~ 10−9 to 10−13 cm2 s−1) hinder the development of the TiO2-based anode materials. To overcome these drawbacks, we present a facile strategy to synthesize N/S dual-doping carbon framework anchored with TiO2 nanoparticles (NSC@TiO2) as LIBs anode. Typically, TiO2 nanoparticles are anchored into the porous graphene-based sheets with N, S dual doping feature, which is produced by carbonization and KOH activation process. The as-obtained NSC@TiO2 electrode exhibits a high specific capacity of 250 mAh g−1 with a coulombic efficiency of 99% after 500 cycles at 200 mA g−1 and excellent rate performance, indicating its promising as anode material for LIBs.

Impact of Li2O/Metal Mole Ratio on Lithium-ion Battery Anode Performance

Impact of Li2O/Metal Mole Ratio on Lithium-ion Battery Anode Performance

A novel approach to synthesize micrometer-sized porous silicon as a high performance anode for lithium-ion batteries

Porous structured silicon (p-Si) has been recognized as one of the most promising anodes for Li-ion batteries. However, many available methods to synthesize p-Si are difficult to scale up due to their high production cost. Here we introduce a new approach to obtain spherical micrometer-sized silicon with unique porous structure by using a microemulsion of the cost-effective of silica nanoparticles and magnesiothermic reduction method. The spherical micron-sized p-Si particles prepared by this approach consist of highly aligned nano-sized silicon and exhibit a tap density close to that of bulk Si particles. They have demonstrated significantly improved electrochemical stability compared to nano-Si. Well controlled void space and a highly graphitic carbon coating on the p-Si particles enable good stability of the structure and low overall resistance, thus resulting in a Si-based anode with high capacity (~1467 mAh g−1 at 2.6 A g−1), enhanced cycle life (370 cycles with 83% capacity retention), and high rate capability (~650 mAh g−1 at 11A g−1). This approach may also be generalized to prepare other hierarchical structured high capacity anode materials for constructing high energy density lithium ion batteries.

Bacterial Cellulose Derived Carbon Nanofibers As High Capacity Anode for Lithium-Ion Batteries

Despite recent developments at lab-scale, Lithium ion is still fastest growing and most promising technology for rechargeable batteries. Although graphite has been conventionally used as anode materials in commercial Li ion batteries, a lot of other allotropes of carbon have also been explored in literature. Carbon nanofibers (CNF) based anode which are primarily derived from polymer precursors such as PAN, SU-8 negative photoresist, cellulose acetate is one such example. However, there is still a need to look for alternative precursors to yield CNF on commercial basis using a scalable, low-cost and sustainable route. Bacterial cellulose, a β-1,4 linked exopolysaccharide which is produced by some special kind of obligate aerobic bacteria is one such potential precursor. Bacterial cellulose which is devoid of lignin, hemicellulose and pectin unlike plant cellulose, comprises three-dimensional (3-D) inter woven nanofibrous network. Bacterial cellulose has several unique properties like higher degree of crystallinity, greater mechanical properties and modability. The fiber morphology and porosity of bacterial cellulose can be controlled to a great extent by employing different fermentation conditions, post treatment (drying and purification) and modifying the network formation by additives in fermentation media. Recent advances not only allows in-situ modification of bacterial cellulose properties using additives but also there are few reports on controlling the orientation and patterning of bacterial cellulose nanofibrils. However there are only few recent studies on exploring the bacterial cellulose as a polymer precursor to carbon upon controlled pyrolysis and to use them as anode. There is still a gap towards the integration of modifying the structural properties of bacterial cellulose and to correlate its effect on as-derived CNF and to further evaluate their electrochemical performance. This work is an effort toward this objective. In the present work, we will first discuss the fermentative production of bacterial cellulose, influence of bioprocess parameters and post production treatments on its physiochemical properties, followed by controlled pyrolysis to yield bacterial cellulose derived CNF. Average diameter of bacterial cellulose CNF was in the range of 20-50 nm. Depending on the fermentation media and growth conditions, crystallinity of bacterial cellulose and its derived carbon can be tuned to a great extent. These bacterial cellulose derived CNF were then used as an anode in half-cell configuration to investigate their electrochemical performance. We shall also present the way forward to explore the in-situ modification of bacterial cellulose to further provide a tight control on the physiochemical properties of CNFs upon pyrolysis with the perspective of their utilization as high performance anode for lithium-ion batteries. Given the scalability and relative low cost production of bacterial cellulose and as-derived CNFs may pave the way of their utilization for commercial electrodes in future. Figure 1

Rational design of hierarchical ZnO@Carbon nanoflower for high performance lithium ion battery anodes

The rational structure design and strong interfacial bonding are crucially desired for high performance zinc oxide (ZnO)/carbon composite electrodes. In this context, micro-nano secondary structure design and strong dopamine coating strategies are adopted for the fabrication of flower-like ZnO/carbon (ZnO@C nanoflowers) composite electrodes. The results show the ZnO@C nanoflowers (2–6 μm) are assembled by hierarchical ZnO nanosheets (∼27 nm) and continuous carbon framework. The micro-nano secondary architecture can facilitate the penetration of electrolyte, shorten lithium ions diffusion length, and hinder the aggregation of the nanosheets. Moreover, the strong chemical interaction between ZnO and coating carbon layer via C-Zn bond improves structure stability as well as the electronic conductivity. As a synergistic result, when evaluated as lithium ion batteries (LIBs) anode, the ZnO@C nanoflower electrodes show high reversible capacity of ca. 1200 mA h g−1 at 0.1 A g−1 after 80 cycles. As well as good long-cycling stability (638 and 420 mA h g−1 at 1 and 5 A g−1 after 500 cycles, respectively) and excellent rate capability. Therefore, this rational design of ZnO@C nanoflowers electrode is a promising anode for high-performance LIBs.

3D red phosphorus/sheared CNT sponge for high performance lithium-ion battery anodes

Phosphorus (P) is considered one of the most attractive anodic materials for lithium-ion batteries (LIBs) owing to its high theoretical specific capacity (2596 mAh g−1). Nevertheless, it suffers from intrinsic poor conductivity (10−12 S m−1) and large volume expansion (~440%) during the lithiation process, leading to low reaction dynamics and serious capacity decay upon cycling. In this work, red P confined in a three-dimensional (3D) sheared carbon nanotube (SCNT) conductive sponge is prepared, showing high capacity and long cyclability as anodes for LIBs. The resultant 3D P-SCNT composite delivers a stable capacity of 1600 mAh g−1 at a current density of 0.1 A g−1 and a reversible high-rate capacity as high as 782 mAh g−1 at 2 A g−1 even after 3000 cycles, owing to the robust support of the SCNT framework and stable chemical bonds between the evenly distributed red P and SCNT.

Degradation of Si/Ge core/shell nanowire heterostructures during lithiation and delithiation at 0.8 and 20 A g-1.

Si/Ge core/shell nanowire heterostructures have been expected to provide high energy and power densities for lithium ion battery anodes due to the large capacity of Si and the high electrical and ionic conductivities of Ge. Although the battery anode performances of Si/Ge core/shell nanowire heterostructures have been characterized, the degradation of Si/Ge core/shell nanowire heterostructures has not been thoroughly investigated. Here we report the compositional and structural changes of the Si/Ge core/shell nanowire heterostructure over cycling of lithiation and delithiation at different charging rates. The Si/Ge core/shell nanowire heterostructure holds the core and shell structure at a charging rate of 0.8 A g-1 up to 50 cycles. On the other hand, compositional intermixing and loss of Si occur at a charging rate of 20 A g-1 within 50 cycles. The operation condition-dependent degradation provides a new aspect of materials research for the development of high performance lithium ion battery anodes with a long cycle life.

A new 3D Dirac nodal-line semi-metallic graphene monolith for lithium ion battery anode materials

Design of a new 3D Dirac nodal-line semi-metallic graphene monolith with potential for a high performance lithium ion battery anode material.

Carbon dioxide as a green carbon source for the synthesis of carbon cages encapsulating porous silicon as high performance lithium-ion battery anodes.

Si/C composite is one of the most promising candidate materials for next-generation lithium-ion battery anodes. Herein, we demonstrate the novel structure of carbon cages encapsulating porous Si synthesized by the reaction between magnesium silicide (Mg2Si) and carbon dioxide (CO2) and subsequent acid washing. Benefitting from the in situ deposition through magnesiothermic reduction of CO2, the carbon cage seals the inner Si completely and shows higher graphitization than that obtained from the decomposition of acetylene. After removing MgO, pores are created, which can accommodate the volume change of the Si anode during the charge/discharge process. As the anode material for lithium-ion batteries, the porous Si/C electrode shows a charge capacity of ∼1124 mA h g-1 after 100 cycles with 86.4% capacity retention at the current density of 0.4 A g-1. When the current density increases to 1.6 and 3.2 A g-1, the capacity can still be maintained at ∼860 and ∼460 mA h g-1, respectively. The prominent cycling and rate performance is contributed by the built-in space for Si expansion, static carbon cages that prevent penetration of electrolyte and stabilize the solid electrolyte interface (SEI) outside, and fast charge transport by the novel structure.

Physico-Chemical and Electrochemical Properties of Nanoparticulate NiO/C Composites for High Performance Lithium and Sodium Ion Battery Anodes.

Nanoparticulate NiO and NiO/C composites with different carbon proportions have been prepared for anode application in lithium and sodium ion batteries. Structural characterization demonstrated the presence of metallic Ni in the composites. Morphological study revealed that the NiO and Ni nanoparticles were well dispersed in the matrix of amorphous carbon. The electrochemical study showed that the lithium ion batteries (LIBs), containing composites with carbon, have promising electrochemical performances, delivering specific discharge capacities of 550 mAh/g after operating for 100 cycles at 1C. These excellent results could be explained by the homogeneity of particle size and structure, as well as the uniform distribution of NiO/Ni nanoparticles in the in situ generated amorphous carbon matrix. On the other hand, the sodium ion battery (NIB) with the NiO/C composite revealed a poor cycling stability. Post-mortem analyses revealed that this fact could be ascribed to the absence of a stable Solid Electrolyte Interface (SEI) or passivation layer upon cycling.

Effect of differentiated textural properties of tin oxide aerogels on anode performance in lithium-ion batteries

Tin oxide aerogels with different textural structures were obtained using epoxide-initiated gelation of a tin precursor and two different gel drying methods, i.e., ambient pressure drying (APD) and supercritical extraction (SCE) processes. The pore diameters of the tin oxide aerogels synthesized by the APD and SCE methods were 11.3 and 25.3 nm, respectively. Tin oxide aerogels with smaller pore sizes and larger specific surface areas as well as slightly smaller pore volumes and porosities were obtained by the APD process. Different retention properties were observed for the anode materials prepared by APD and SCE, (71.8% and 10.9% after 80 cycles, respectively). This study revealed a relationship between the pore structure of the metal oxide anode material and its cyclability in Li-ion batteries, with metal oxide aerogels with small pore sizes and large specific surface areas showing greatly improved cycling stability in Li-ion battery applications owing to enhanced stability of the pore structure.

Graphene-oxide-wrapped ZnMn2O4 as a high performance lithium-ion battery anode

Cation distribution between tetrahedral and octahedral sites within the ZnMn2O4 spinel lattice, along with microstructural features, is affected greatly by the temperature of heat treatment. Inversion parameters can easily be tuned, from 5%–19%, depending on the annealing temperature. The upper limit of inversion is found for T = 400 °C as confirmed by x-ray powder diffraction and Raman spectroscopy. Excellent battery behavior is found for samples annealed at lower temperatures; after 500 cycles the specific capacity for as-prepared ZnMn2O4 is 909 mAh g−1, while ZnMn2O4 heat-treated at 300 °C is 1179 mAh g−1, which amounts to 101% of its initial capacity. Despite the excellent performance of a sample processed at 300 °C at lower charge/discharge rates (100 mAh g−1), a drop in the specific capacity is observed with rate increase. This issue is solved by graphene-oxide wrapping: the specific capacity obtained after the 400th cycle for graphene-oxide-wrapped ZnMn2O4 heat-treated at 300 °C is 799 mAh g−1 at a charge/discharge rate 0.5 A g−1, which is higher by a factor of 6 compared to samples without graphene -oxide wrapping.

Improved lithium-ion battery anode performance via multiple element approach

In this work, single (Co3O4), binary (Co3O4/ZnO) and ternary (Co3O4/ZnO/NiO) nanomaterials were successfully synthesized by Pechini method followed by a calcination step. Electrochemical lithium storage capabilities of the anode materials were studied. The results showed that the best capacity retention and lowest voltage hysteresis was achieved with ternary material. The ternary material showed a first cycle charge capacity of 649 mAh/g at 70 mA/g and maintained 83% of this capacity after 39 cycles. The results demonstrated the positive impact of multiple element strategy on the cycle life of anode materials.

Functionalized fullerenes for highly efficient lithium ion storage: Structure-property-performance correlation with energy implications

Here, we report that spherical C60 derivatives with well-defined molecular structures hold great promise to be advanced anode materials for lithium-ion batteries (LIBs). We studied four C60 molecules with various functional groups, including pristine, carboxyl, ester, and piperazine C60. The comparison of these C60s elucidated a strong correlation between functional group, overall packing (crystallinity), and the anode performance in LIBs. Specifically, carboxyl C60 and neutral ester C60 showed higher charge capacities than pristine C60, whereas positively-charged piperazine C60 exhibited lower capacity. The highest charge capacity was achieved on the carboxyl C60 (861mAhg−1 at 100th cycle), which is five times higher than that of pristine C60 (170mAhg−1), more than double the theoretical capacity of commercial graphite (372mAhg−1), and even higher than the theoretical capacity of graphene (744mAhg−1). Carboxyl C60 also showed a high capacity at a fast discharge-charge rate (370mAhg−1 at 5C). The exceptional performance of carboxyl C60 can be attributed to multiple key factors. They include the complex formation between lithium ions and oxygen atoms on the carboxyl group, the improved lithium-binding capability of C60 cage due to electron donating from carboxylate groups, the electrostatic attraction between carboxylate groups and lithium ions, and the large lattice void space and high specific area due to carboxyl functionalization. This study indicates that, while maintaining the basic C60 electronic and geometric properties, functionalization with desired groups can achieve remarkably enhanced capacity and rate performance for lithium storage.

Helical mesoporous carbon nanoribbons as high performance lithium ion battery anode materials

Abstract Design and synthesis of novel carbon nanomaterials as the anodes for lithium ion batteries (LIBs) is of great importance for modern electronic devices and electric vehicles. In this work, helical resorcinol–formaldehyde resin/silica composite nanoribbons were prepared via a sol–gel process using self-assembly of a cationic gelator as the template, resorcinol, formaldehyde and tetraethyl orthosilicate as the precursors. After carbonization under argon at 600 °C, followed by washing with dilute HF solution to remove the silica compound from the nanocomposites, helical mesoporous carbon nanoribbons were finally obtained. X-ray diffraction and Raman spectrum indicated that the walls of the nanoribbons are predominantly amorphous carbon. Electrochemical measurements showed that at a current density of 0.1 A/g, the helical mesoporous carbon nanoribbons delivered a high reversible capacity of 704.6 mAh/g over 120 cycles, indicating that they are promising anode materials for LIBs compared with the currently commercial graphitic materials.