Anode For Lithium Storage Research Articles

Self-assembly of antimony sulfide nanowires on three-dimensional reduced GO with superior electrochemical lithium storage performances

The three-dimensional Sb2S3 nanowires/reduced graphene oxide (SBSWs/rGO) was prepared as an anode for lithium storage by self-assembling SBSWs on 3D rGO framework. SBSWs/rGO shows the perfect rate capability (505 mAh g−1 at 3 A g−1) and long cycle stability (697 mAh g−1 after 100 cycles at 100 mA g−1). The 3D rGO framework has good structural stability, which can provide a free space towards shortening lithium ions diffusion paths and accommodating the volume change of SBSWs. The rGO sheets with high electrical conductivity promote electron transfer in composites to improve rate performances.

Energy Accumulation Enabling Fast Synthesis of Intercalated Graphite and Operando Decoupling for Lithium Storage

AbstractMetal chloride‐intercalated graphite with multiple/versatile functions is one of the promising categories for charge storage, especially in achieving high volumetric and gravimetric performance simultaneously. Herein, a novel field‐induced energy accumulation strategy is proposed and demonstrated to achieve minute‐level fast preparation of stage‐1 dominated FeCl3‐graphite intercalation compounds (GICs). The microwave‐induced Joule heat and electron excitation from the graphite conjugated system produce the arc plasmas with high energy density in the limited microenvironment, accompanied by the enhanced internal energy of gaseous reactant molecules and the strengthened intercalation reaction kinetics. When evaluating the anode for lithium storage, the FeCl3‐graphite intercalation compounds feature the promoted self‐activation characteristics and deliver a high volumetric capacity up to 1650 mAh cm−3. In particular, with the assistance of the operando Raman technique, it is interesting to find that the electronic decoupling effect among graphite and FeCl3 layers is responsible for the self‐activation process. Thus, it is reasonable to believe that this work can further offer an insightful and referable idea into the in‐depth investigation of metal chloride intercalated graphite, especially for applications in lithium storage.

Aligned graphene array anodes with dendrite-free behavior for high-performance Li-ion batteries

Low rate-performance and safety issue associated with lithium dendrite plating under abuse conditions seriously limit the further application of graphite-based anode for lithium storage. Here, we report a high-performance, dendrite-free anode enabled by highly-ordered graphene arrays. This rationally designed anode consists of periodically arranged graphene sheets and interlayer-pillared carbon dots. This resultant anode performs a specific capacity of 64.5 mAh g−1 at high current density of 6 C, ~4.5 times higher than the commercial graphite anode counterpart. More importantly, the resultant anode performs lithium dendrite-free behavior even after over-lithiation, indicating its fast Li-ion transport kinetics and high structural stability. The current work provides a simple and effective strategy on electrode materials for fast charging and safe LIBs towards practical applications.

Carbon-enriched SiOC ceramics with hierarchical porous structure as anodes for lithium storage

Honeycomb-like carbon-enriched SiOC ceramics were prepared with tetraethoxysilane and phenyltriethoxysilane as sol–gel precursor, and followed by etching with NaOH. The microstructure evolution, chemical composition and lithium storage performance of SiOC ceramics were investigated. The phase separation of SiOC ceramics occurs as the elevation of pyrolysis temperature. The reaction of SiO4 units with NaOH not only generates hierarchical porous structure, but also increases the relative content of C and Si-O-C phase. The porous SiOC ceramic (H-SiOC-900) possesses a high specific surface area of 503.62 m2g−1 and pore volume of 0.41 cm3g−1, and delivers a high reversible capacity of 961 mAh g−1 and 480 mAh g−1 at the current density of 50 mA g−1 and 500 mA g−1, respectively. Although the reversible capacity of porous SiOC ceramics is improved as the increase of SiO3C and SiO2C2 microstructures, the C content determines the electrochemical performance of bulk and honeycomb-like SiOC ceramics.

Bi and Sn particles embedded in ZIF-8-derived porous carbon as anode for lithium and sodium storage

Recently, Bi element shows superior and stable performance as a battery anode material candidate for Li-ion and Na-ion storage. However, the challenge is the enormous volume change in the cycling procedure of alloy-type materials that could lead to pulverization of the electrode and gradual reduction in its capacitance. To counter the same, porous carbon and Sn were chosen as cushion layers for Bi. As a result, Bi and Sn embedded in ZIF-8-derived three-dimensional porous carbon (Bi/Sn@3D-C) composite was specifically designed as an electrode material for Li-ion and Na-ion storage. The electrochemical performance of Bi/Sn@3D-C, Bi@3D-C, and Sn@3D-C is compared. The discharge capacity of Bi/Sn@3D-C remains 632.0 mA h g−1 (at a rate of 0.1 A g−1) after 120 cycles for Li-ion store, and after 50 cycles, the specific capacity of the electrode reaches 291.5 mA h g−1 in sodium-ion battery.

Facile synthesis of one-dimensional vanadyl acetate nanobelts toward a novel anode for lithium storage.

Transition metal oxides (TMOs) are prospective anode materials for lithium-ion batteries (LIBs), owing to their high theoretical specific capacity. However, the inherently low conductivity of TMOs restricts their application. The coupling of lithium-ion conducting polymer ligands with TMO structures is favorable for the dynamics of electrochemical processes. Herein, vanadyl acetate (VA) nanobelts, an organic-inorganic hybrid material, are synthesized for the first time as an anode material for LIBs. As a result, the VA nanobelt electrode displays an outstanding electrochemical performance, including a highly stable reversible specific capacity (around 1065 mA h g-1 at 200 mA g-1), superior long-term cyclability (with a capacity of approximately 477 mA h g-1 at 2 A g-1 over 500 cycles) and attractive rate capability (1012 mA h g-1 when the current density recovers to 200 mA g-1). In addition, scanning electron microscopy (SEM), cyclic voltammetry (CV) curves at different scanning rates and electrochemical impedance spectroscopy (EIS) are used to investigate the variation of the specific capacity and the electrochemical kinetic characteristics of the VA electrode during cycling in detail, respectively. Also, the structural variations of the VA electrode in the initial two cycles are also investigated by in situ XRD testing. The periodic evolution of the in situ XRD patterns demonstrates that the VA nanobelt electrode shows excellent reversibility for Li+ ion insertion/extraction. This work offers an enlightening insight into the future research into organo-vanadyl hybrids as advanced anode materials.

Ant-nest-like Cu2-xSe@C with biomimetic channels boosts the cycling performance for lithium storage.

Controlling the microstructure and composition of electrodes is crucial to enhance their rate capability and cycling stability for lithium storage. Inspired by the highly interconnected network and good mechanical integrity of an ant-nest architecture, herein, a biomimetic strategy is proposed to enhance the electrochemical performance of Cu2-xSe. After facile carbonization and selenization treatments, the 3D Cu-MOF is successfully transformed into the final ant-nest-like Cu2-xSe@C (AN-Cu2-xSe@C). The AN-Cu2-xSe@C is composed of interconnected Cu2-xSe channels with amorphous carbon coated on the outer surface. The 3D interconnected channels within the AN-Cu2-xSe@C provide fast charge transport pathways and enhanced structural integrity to tolerate the large volume fluctuations of Cu2-xSe during cycling. When applied as the anode for lithium storage, the AN-Cu2-xSe@C shows remarkable electrochemical performance with a high capacity of 1452 mA h g-1 after 1200 cycles at 1.0 A g-1 and 879 mA h g-1 after 2500 cycles at 10.0 A g-1, respectively. Mechanism investigations demonstrate that the AN-Cu2-xSe@C experiences complicated conversion-intercalation co-existence reactions upon cycling. The existence of capacitive behaviour (74%) also contributes to the extended cycling performance. Our work offers a new avenue for designing a high performance electrode using the biomimetic concept.

Reaction Mechanism Exploration of Binary Oxide Bi2Mo3O12@Ti3C2 Composite As Anode for Li-Ion Capacitor

Metal oxides as pseudocapacitive materials are widely explored as anode for lithium ion capacitors, owing to their high volumetric and gravimetric lithium storage capacities. We present studies on reaction mechanism of binary Bi2Mo3O12 oxide as an anode for lithium storage. In-situ synchrotron XRD measurements are performed on this exotic material to elucidate lithium storage behaviors, coupled with voltage resolved CVs and ex-situ XPS analyses. Synergistic effect is believed to be the factor on improving electrochemical performance of the binary metal oxide anode instead of simple combination of two single components. The Bi2Mo3O12 anode undergoes an initial irreversible conversion reaction resulting in metallic Bi and Li2MoO4 on electrochemical discharge down to 0.01 V vs. Li+/Li. During successive cycling, the two components reversibly uptake and release lithium ions through alloying/de-alloying and intercalation/de-intercalation reactions by forming Li3Bi alloy and Li2+xMoO4. Cycling stability of the Bi2Mo3O12 anode is considerably enhanced by in-situ composition of Ti3C2 MXene. The Bi2Mo3O12@Ti3C2 composite anode exhibits 227 mAh/g capacity upon prolonged 1000 cycles at 2.5 A/g high charge/discharge rate in the voltage range of 3.0 - 0.01 V. This performance indicates the Bi2Mo3O12@Ti3C2 composite can be a potential candidate as anode for Li-ion capacitors.

Interconnected porous N-doped carbon coated cobalt/iron oxides core shell nanocomposites for superior lithium storage anode

The design and fabrication of transition metal oxides (TMOs) anode with superior lithium storage performance remains a challenge. Herein, we demonstrate one-pot hydrothermal method combined with post-calcination for the construction of interconnected porous N-doped carbon-coated cobalt/iron oxides nanocomposite (CFO@N-C) as lithium-ion batteries (LIBs) anode. This facile approach gives CFO@N-C many interesting characters such as rich porous structure, fine cobalt/iron oxides’ nanocrystals (<10 nm), interconnected carbon coating layer (~3–20 nm) and high nitrogen content (33.2 wt%, N/C). When evaluated as LIBs anodes, it rendered a reversible capacity of about 1218 mAh g−1 at 0.2 A g−1 after 100 cycles, a remarkable discharge capacity of about 376.8 mAh g−1 was retained after 400 cycles even at current density of 10 A g−1. Cyclic voltammetry revealed there exists a notable capacitive contribution, especially at high rate (74.2% at ~5C). Electrochemical impedance spectroscopy disclosed that CFO@N-C electrode possesses not only a low charge transfer resistance, but also a high Li diffusion coefficient, about 60 times that of pure cobalt ferrite electrode.

Revealing the unique process of alloying reaction in Ni-Co-Sb/C nanosphere anode for high-performance lithium storage

The strategy of “template sacrifice method” was proposed to synthesize well-defined NiSb/CoSb nanoparticles embedded in carbon nanosphere (Ni-Co-Sb/C, ~560 nm) by calcination treatment of the Ni-Co-MOF (metal-organic framework) precursor. Due to the structural controllability of MOF precursor and Ni/Co bimetallic synergy, the fabricated Ni-Co-Sb/C demonstrates a high surface area (88 m2 g−1) and superior ion conductivity, thus an excellent electrochemical performance as has been achieved as lithium ion battery (LIB) anode. A reversible discharge specific capacity as high as 495.1 mAh g−1 has been stably delivered after 1000 cycles at a high current density of 1.0 A g−1. In addition, the charge transfer impedance of Ni-Co-Sb/C electrode is as low as 67.6 Ω in the 30th cycle at 0.1 A g−1 and the pseudocapacitive contribution is as high as 73.8% at 0.5 mV s−1. The alloying mechanism of Ni-Co-Sb/C has been verified by in-situ X-ray diffraction (XRD), which enables a high lithium storage capacity. Moreover, the full-cell assembled with LiCoO2 as cathode exhibits a steady discharge specific capacity of 354.0 mAh g−1 at 0.1 A g−1 even after 100 cycles. Our work provides an effective method for the application and high-capacity Sb-based material in energy storage fields, and this material is expected as a promising candidate for a novel anode material in LIBs.

Engineering edge-exposed MoS2 nanoflakes anchored on the 3D cross-linked carbon frameworks for enhanced lithium storage

High-rate capability and long cycle life are currently the two most major challenges for high-power rechargeable batteries such as lithium-ion batteries (LIBs), sodium-ion batteries (SIBs). Developing electroactive materials with high-efficiency electron/ion transport network and robust mechanical stability is a key. Herein, we have successfully designed and fabricated 3D cross-linked nitrogen-doped carbon nanosheet frameworks with good interconnection and hierarchical nanostructures, and simultaneously decorated edge-enriched molybdenum disulfide (MoS[Formula: see text] nanoflakes inside the whole carbon scaffold via a salt template assisted confinement pyrolysis strategy, yielding the unique 3D carbon scaffold/MoS2 hybrids. In such a design, such hybrids not only facilitate lithium diffusion kinetics and efficient utilization of MoS2nanoflakes owing to much exposed edges and well interconnection between active components and carbon frameworks, but also provide highly efficient electron/ion transport pathway. When evaluated as anode for lithium storage, the obtained products show superior rate capability of 284 mAh g[Formula: see text] up to 5 A g[Formula: see text] and long-term cycling stability. This work demonstrates an efficient solution to design and construct a high-efficiency electron/ion transport network for high-power applications for energy storage devices.

Highly monodispersed Fe2WO6 micro-octahedrons with hierarchical porous structure and oxygen vacancies for lithium storage

High-volume capacity electrode materials are the key to the development and application of lithium-ion batteries in electric vehicles and small consumer electronics. Here, through simply calcination the W-based metal-organic frameworks, a novel Fe2WO6 hierarchical porous octahedra with oxygen vacancies are successfully constructed. Oxygen vacancies can enhance the conductivity of the material, provide more Li+ storage sites, while the hierarchical porous structure effectively buffers the volume expansion and promotes the diffusion of the electrolyte. Besides, by introducing the heavy element W, the compact density of Fe2WO6 is as high as 2.9 g cm−3. Thus, an ultrahigh volumetric capacity of 4785 mAh cm−3 (0.2 A g−1), and superior rate capability of 2323 mAh cm−3 (4.0 A g−1) could be achieved by Fe2WO6 anode, which is the best performance of W-based anode so far. Furthermore, the mechanism of the significant increment in capacity is also investigated. The new findings indicate that the phase transition and structural rearrangement of the Fe2WO6 electrode, along with the enhanced reversible formation and decomposition of the polymer/gel-like film, collectively result in the capacity evolution during cycling. Remarkably, the introduction of oxygen vacancies and high density makes hierarchical porous Fe2WO6 a promising anode for high volumetric lithium storage.

A self-driven alloying/dealloying approach to nanostructuring micro-silicon for high-performance lithium-ion battery anodes

The nanostructuring of low-cost micro-sized silicon (mSi) is paramount to achieve the practical viability of deploying high-capacity Si anodes for lithium-ion batteries (LIBs). Conventional methods for converting mSi to nanoporous Si (nSi) involve low product yield, toxic chemical reagents, high energy consumption, etc. Herein, we report a self-driven alloying/dealloying approach to converting mSi to nSi in molten salts, where mSi alloys with Mg powders to generate Mg2Si and, subsequently, the Mg2Si dealloys in a Mg2Si||Sn primary battery with the production of nSi at the negative electrode and the liquid Mg-Sn alloy at the positive electrode. Finally, the Mg-Sn decomposes to Mg gas and liquid Sn through a vacuum-distillation process. Taking the micro-sized Si kerf waste as an example, the pyrolytic carbon-coated (PCC) nSi delivers a capacity of 1080.2 mAh g−1 at 1 A g−1 after 1000 cycles with a capacity retention rate of 83.7%. Furthermore, a fabricated PCC-nSi-2||LiNi0.6Co0.2Mn0.2O2 (NCM622) full cell demonstrates a high energy density of 466 Wh kg−1 as well as good cycling stability for 200 cycles. The improved Li-storage performance is attributed to the synergetic effects of the nanoporous Si and carbon coating. Overall, the self-driven nanostructuring approach along with the vacuum-distillation process maintains a high utilization of mSi, eliminates the use of toxic reagents, and keeps a closed-loop material circle, and thus offers an efficient and green pathway to valorize various mSi for making enhanced lithium-storage anodes.

High-effective preparation of 3D hierarchical nanoporous interpenetrating network structure carbon membranes as flexible free-standing anodes for stable lithium and sodium storage

Ideal lithium/sodium storage requires a simple and effective design of carbon-based anodes with appropriate morphologies/microstructures and excellent flexibility. Herein, an advanced flexible interpenetrating network carbon membrane with 3D hierarchical nanopore structure is designed and fabricated inspired by porous membrane technology via nonsolvent induced phase separation (NIPS) and carbonization. The interpenetrating network structure in the carbon membrane is generated by the NIPS membrane formation process, while the 3D hierarchical nano-porous structure is obtained from polymer decomposition during carbonization. The unique synergistic effect between the even interpenetrating network structure and the developed 3D hierarchical porous structure not only ensured structural integrity of the anodes and provided a high-volume ion transmission reservoir, but also endowed carbon membranes with multiple active sites for energy storage. As flexible anodes, the resulting carbon membranes achieved enhanced electrochemical properties by showing maximum reversible capacitance of 351.8 mA h g−1 in lithium storage and 237.4 mA h g−1 in SIBs at a current density of 50 mA g−1. In both LIBs and SIBs, the carbon membranes exhibit outstanding rate performance even at a high current density of 2000 mA g−1. They also show excellent long-term cycling stability with the coulomb efficiency maintained nearly 100 % after the first few cycles. Therefore, this work provides a simple and high-effective cross-disciplinary approach through membrane technology and carbon materials for the production of high-performance, low-cost carbon membranes for large-scale application anodes.

Tin-based organic sulfides with highly reversibility of conversion reaction synthesized at room temperature as anode for lithium storage

Increasing the degree of dispersion is of great significance for improving the electrochemical performance of tin-based materials. The smaller size is conducive to alleviating the volume effect and improving the reversibility of the conversion reaction, thus improving the cyclic stability and reversible capacity of tin-based anode materials. In this work, tin-based organic sulfide is synthesized by potassium ethyl xanthate, and graphene is added to enhance the conductivity of the electrode material. The anode material exhibits excellent performance with the residual capacity of 657 mAh g−1 after 400 cycles at the current density of 200 mA g−1. The differential charge capacity (dQ/dV) curves show that the conversion reaction of electrode materials has good reversibility and is maintained until the end of the cycle. We also investigated the effect of calcination temperature on the conversion reaction, and verified that it is important to maintain the tin-organic structure for the reversibility of the conversion reaction.

Nanosized Si space-confined in 3D porous Cu as anode for high-performance lithium storage

Silicon (Si) possesses high theoretical lithium-ion (Li+)-storage capability but is still limited to a huge volume change in the charging–discharging process and has poor conductivity, which hinders its application. Here, the authors report a novel three-dimensional (3D) continuous porous silicon/copper (Cu) composite film through non-solvent-induced phase separation and heat treatment. The composite film inherits the developed 3D channels of copper with a proper pore size (1–5 μm), while the silicon particles can evenly adhere onto the 3D copper current collector tightly by heat treatment. It provides a reversible capacity of up to 2054.9 mAh/g after 150 cycles under a current of 0.05 C and exhibits a good rate capability (609.9 mAh/g at a high rate of 1 C) when used as an electrode. Naturally, the 3D porous architecture could not only shorten the electron/ion transmission path but also induce space-confined silicon, which provides a stable space for the volume expansion/contraction of silicon to restrict pulverization. This strategy provides ideas for the development of high-energy-density electrodes for next-generation energy-storage systems.

Growing ordered CuO nanorods on 2D Cu/g-C3N4 nanosheets as stable freestanding anode for outstanding lithium storage

Two dimensional (2D) nanostructures are promising to provide a new hierarchical architecture for transition metal oxides (TMOs) with outstanding lithium storage. In this work, we grew ordered CuO nanorods on 2D Cu/g-C3N4 nanosheets to form the hierarchical CuO@Cu/g-C3N4 nanorods film as freestanding anode for advanced lithium storage. This assembled freestanding film demonstrates a high discharge specific capacity at 726 mAhg−1 after 200 cycles at 0.1C and a discharge specific capacity of 457 mAhg−1 after 625 cycles at 1C, among the best performance in CuO and CuO based nanostructures for lithium storage. Its outstanding stability and cyclic performance are ascribed to the following aspects during the reaction process: (i) the unique 2D nanostructure provides large exposed area for Li+ insertion, (ii) the ordered CuO nanorods provide interior spaces to accommodate the volume change and offer more paths for charges and Li+ transfer, (iii) the existence of Cu nanosheets increases the electrons transport and (iv) the porous g-C3N4 nanosheets endow the prepared structure more active sites for facilitating Li+ transport and accommodating volume change. Our strategy on growing ordered nanostructures on 2D nanosheets will be an effective way to modify TMOs for advanced lithium-ion batteries.

Decoding of Oxygen Network Distortion in a Layered High-Rate Anode by In Situ Investigation of a Single Microelectrode.

Sluggish conversion reactions severely impair the rate capability for lithium storage, which is the main disadvantage of the conversion-type anode materials. Here, the microplatform based on a single microelectrode is designed and utilized for the fundamental understanding of the conversion reaction. The kinetic-favorable layered structure of the anode material is on-site synthesized in the microplatform. The in situ characterization reveals that introducing an oxygen network distortion in the layered oxide anode effectively circumvents the severe passivation of the electrode material by lithium oxide, thus leading to highly reversible conversion reactions. As a result, the high-rate capability of the conversion-type anode materials is realized. The on-site synthesis strategy is further applied in the large-scale synthesis of nanomaterials for lithium-ion batteries. As such, oxide nanorods with the layered structure are synthesized by a facile chemical strategy, showing high rate performance (574 mAh g-1 at 10 A g-1). This work unveils the beneficial effect of oxygen network distortion in the layered anode for conversion reactions over cycling, thus providing an alternative strategy to enhance the rate capability of conversion-type anodes for lithium storage.

Construction of pseudocapacitive Li2-xLaxZnTi3O8 anode for fast and super-stable lithium storage

Lithium-ion capacitors (LICs) composed of battery-type anodes with large energy densities and capacitor-type cathodes with high power densities are considered as appealing energy-storage devices. Here, a LIC with good performance is constructed using active carbon (AC) as the cathode and Li1.95La0.05ZnTi3O8 (LL5ZTO) as the anode. LL5ZTO doped with La is synthesized via a one-step solid-state route. The kinetics and structural stability of LZTO are enhanced by La-doping. Thus, LL5ZTO exhibits good Li-storage performance. The discharge specific capacity reaches 182.6 mAh g−1 at 3 A g−1 (120th cycle) for LL5ZTO. The LIC based on the LL5ZTO anode and the AC cathode delivers an energy density of 59.72 Wh kg−1 at 846.4 W kg−1, and a high power density of 8771 W kg−1 at 19.49 Wh kg−1. Furthermore, the capacity retention is over 90% after 3000 cycles for the LIC at 2 A g−1. The good electrochemical performance indicates that the constructed LIC is expected to use in advanced energy storage devices.

High-performance ternary metal oxide anodes for lithium storage

Metal oxide anodes which can achieve high lithiation capacities by conversion mechanism are promising in lithium storage systems. The main obstacle to their practical applications is poor cycling performance. Regulating element ratio of multi-metal materials is effective for improving their electrochemical properties. Herein, optimized Mn–Ni–Co–O anode materials with long-cycle stability are reported. The improvement is associated with proper element ratio, which enables accelerated Li+ ion diffusion and high-stability LiF-rich solid electrolyte interphase (SEI) layer. As a result, (Ni0·1Co0·3Mn0.6)3O4 materials deliver lithiation capacities of 500 mAh g−1 after 1500 cycles at the current density of 1 A g−1. It is greatly better than other samples with different element ratio. Then, application properties of (Ni0·1Co0·3Mn0.6)3O4 materials are evaluated by assembled with active carbon and LiFePO4 for energy storage devices, respectively. The obtained Li-ion capacitor exhibits high energy densities of 112 Wh kg−1 based on total mass of oxides and active carbon. The obtained Li-ion battery also shows good cycle stability. These results suggest lithiation capacity fade of metal oxide anodes can be mitigated by controlling their component contents. This low-cost and high effective way is to promote commercial applications of metal oxide anode materials in energy storage systems.