Anode For Lithium-ion Batteries Research Articles

Interfacial modulation of hollow ZnS-SnS2 microboxs by Ti3C2Tx MXene to construct three-dimensional hybrid anodes for lithium-ion batteries with ultra high stability at low temperature

Metal sulfides exhibit obvious volume expansion due to the inherent poor conductivity and large temperature fluctuations, leading to reduced storage capacity. Herein, an electrostatic self-assembly strategy was proposed to fabricate a three-dimensional (3D) polyaniline (PANI) encapsulated hollow ZnS-SnS2 (H-ZSS) heterojunction confined on Ti3C2Tx MXene nanosheets (H-ZnS-SnS2@MXene@PANI, denoted as H-ZSSMP), which exhibits remarkable reversible capacity and cyclic stability (520.3 mAh/g at 2 A/g after 1000 cycles) at room temperature. Additionally, specific capacity can stabilized at 362.5 mAh/g for 250 cycles at −20 °C. A full cell with the configuration of H-ZSSMP//lithium iron phosphate (LiFePO4) can retain a satisfactory reversible capacity of 424.7 mAh/g after 100 cycles at 0.1 C. Theory calculations confirm heterogeneous interface can accelerate the transfer of ions through the interfacial regulation effect of MXene on H-ZSS. Our work provides a simple strategy to improve the capacity and stability of lithium-ion batteries (LIBs), as well as the new applications of MXene and bimetallic sulfides as anode materials, which will facilitate the development of MXene based composites for energy storage.

Layered Siloxene Microparticles: Unveiling Long-Term Stability and High Volumetric Capacity for Advanced Lithium-Ion Batteries

Two-dimensional (2D) Si π materials, a silicon counterpart of graphene, are particularly interesting because they exhibit intrinsic electrochemical and mechanical behavior combined with structural anisotropy. This work aims to improve the Li-storage performance of 2D siloxene (2DSi) microparticles by co-imidization with polymer binder. The proposed method combines 2DSi with poly(amic acid) to form a covalently bound poly(imide) (PI) layer upon thermal dehydration. Electrochemical evaluations reveal that the resulting 2DSi-PI electrode exhibits a unique electrochemical behavior toward Li+ based on intercalation, with additional reversible (de-)lithiation attributed to carbonyl oxygens of PI. Without suffering volume expansion, the 2DSi-PI electrodes display a highly stable capacity generation of 585 mAh g−1 at 250 mA g−1 with a capacity loss of 0.13 % per cycle at the 200th cycle. In addition, the full-cell of the 2DSi-PI electrode combined with the LiNi0.8Co0.1Mn0.1O2 cathode achieves an energy density of 426 Wh kg−1 at a power density of 1,155 W kg−1. Ex-situ and theoretical analyses of the (de-)lithiated 2DSi-PI electrodes demonstrate that the surface-bound PI suppresses solvent reduction, increases the amount of LiF in the SEI layer, and improves the binding affinity of 2DSi to LiF. As a result, the cycle stability of 2DSi-PI electrodes is significantly improved in comparison to 2DSi-polyvinylidene fluoride electrodes. Co-imidization with PI emerges as a promising strategy for advancing the electrochemical properties of 2DSi electrodes, offering insights for the design of high-performance lithium-ion battery anodes.

Enhancing the lithium storage properties of SiO@NC anode by MnNb2O6 decoration

The scalable application of SiO anode in lithium ion batteries is still limited by its low initial Coulombic efficiency and inferior cycle stability. Compositing SiO with other substances that own high structural stability, fast Li ion diffusion rate and good Li ion storage capacity has been proven of effectiveness to tackle the aforementioned problems. Herein, manganese niobate (MnNb2O6) that possesses 3-dimensional Li ion diffusion channels is used to modify SiO anode in conjunction with N-doped carbon coating to improve the Li-ion storage performance. Ex situ XRD measurements reveal that the orthorhombic MnNb2O6 is converted to amorphous LixMnNb2O6 during lithiation and reversed back to MnNb2O6 in the following delithiation process. The crystal structure of MnNb2O6 is well preserved after a long-term cycle test, suggesting its high structural stability. With such stable structure and ultrafast Li ion diffusion kinetics, the optimized SiO@MnNb2O6@NC composite anode exhibits obviously improved rate performance and cycle stability as compared to SiO@NC. A reversible capacity of 835 mAh g−1 is maintained at a relatively high current density of 3.0 A g−1, and a discharge capacity of 799 mAh g−1 is preserved after 200 cycles at 1.0 A g−1. This work provides a facile and promising strategy to modify SiO-based anode with Columbite-type Nb-based metal oxides towards better Li-ion storage properties.

Porous Si/Ca-Si-O nanocomposite lithium storage materials by calciothermic reduction of Si with CaH2

Silicon monoxide (SiO)-based anode materials are one of the most intensively investigated class of materials for use as high-capacity anodes in lithium-ion batteries. However, their low initial Coulombic efficiency (ICE), resulting from the irreversible electrochemical reaction of the amorphous SiO2 (a-SiO2) phase in the SiO, restricts the wide-spread adoption of SiO-based anode materials in lithium-ion batteries. Pre-emptive formation of an irreversible phase that converts a-SiO2 to a non-reactive state with lithium prior to cell assembly has received much attention for enhancing ICE. However, this process has the drawback of not ensuring long-term cycle performance. Herein, the pre-emptive formation of irreversible phase combined with the high-energy mechanical milling (HEMM) process is proposed to simultaneously improve both the ICE and long-term cycle performance. The resulting porous Si/Ca-Si-O nanocomposite electrode exhibits an impressive ICE of 86.4 % and maintains 55 % of its capacity over 200 cycles. The key factor in the significant ICE improvement is the irreversible Ca-Si-O phase, which is formed by the calciothermic reduction of Si with CaH2. In addition, the microstructural changes induced by the HEMM process effectively mitigate the volume expansion of Si during cycling, resulting in improved long-term cycle stability.

Silicon-tin thin-film anodes for low and high power-density lithium-ion batteries

Silicon (Si) is a promising replacement material for graphite, the commonly utilized anode material in lithium-ion batteries (LIBs). Si has a theoretical specific capacity up to 11 times higher than that of graphite. However, pure Si has two main issues: high electronic resistivity and significant volume change during charge/discharge cycling. To overcome these issues, Si was alloyed with high-conductivity materials. In this contribution, physical vapor deposition was utilized to produce binderless silicon-tin anodes for LIBs. Tin is a lithium-active alloying material that has high electrical conductivity and high specific capacity (i.e., up to three times that of graphite). Electronic resistivity, residual film stress, X-ray photoelectron spectroscopy, Raman spectroscopy, and cyclic voltammetry measurements were performed to thoroughly analyze the deposited Si-Sn films and help understand their charge/discharge cycling performance at low and high C-rates. At a low C-rate of 0.5 C, the alloyed films did not show any improvement compared to pure Si. However, the alloyed films showed better performance compared to pure Si when tested at a high C-rate of 10 C. Si-Sn films with (40 – 50 wt.% Sn) were able to retain a specific capacity of around 680 mAh g−1 after 1000 cycles.

Design of Supported–Coated Structure Silicon/Carbon Composites Using Industrial Waste Micrometer-Sized Silicon for an Advanced Lithium-Ion Battery Anode

Design of Supported–Coated Structure Silicon/Carbon Composites Using Industrial Waste Micrometer-Sized Silicon for an Advanced Lithium-Ion Battery Anode

Exploring Lead Zirconate Titanate, the Potential Advancement as an Anode for Li-Ion Batteries.

Graphite, widely adopted as an anode for lithium-ion batteries (LIBs), faces challenges such as an unsustainable supply chain and sluggish rate capabilities. This emphasizes the urgent need to explore alternative anode materials for LIBs, aiming to resolve these challenges and drive the advancement of more efficient and sustainable battery technologies. The present research investigates the potential of lead zirconate titanate (PZT: PbZr0.53Ti0.47O3) as an anode material for LIBs. Bulk PZT materials were synthesized by using a solid-state reaction, and the electrochemical performance as an anode was examined. A high initial discharge capacity of approximately 686 mAh/g was attained, maintaining a stable capacity of around 161 mAh/g after 200 cycles with diffusion-controlled intercalation as the primary charge storage mechanism in a PZT anode. These findings suggest that PZT exhibits a promising electrochemical performance, positioning it as a potential alternative anode material for LIBs.

Graphene-doped silicon-carbon materials with multi-interface structures for lithium-ion battery anodes

The carbon nanomaterials are usually used to improve the electrical conductivity and stability of silicon (Si) anodes for lithium-ion batteries. However, the Si-based composites containing carbon nanomaterials generally show large specific surface area, leading to severe side reactions that generate large amounts of solid electrolyte interphase films. Herein, we embedded graphene oxide (GO) and silicon nanoparticles (Si NPs) uniformly in pitch matrix by solvent dispersion. The internally doped GO reduces the exposed surface and improves the electrical conductivity of the composite. Meanwhile, the multi-interface structures are constructed inside to limit the domains of Si NPs and improve the structural stability of the material. When evaluated as anodes, the Si/graphene/pitch-based carbon composite anode exhibits the outstanding electrochemical properties, delivering a reversible capacity of 820.8 mAh/g at 50 mA g−1, as well as a capacity retention of 93.6 % after 1000 cycles at 2 A/g. In addition, when assembled with the LiFePO4 cathode, the full cell exhibits an impressive capacity retention of 95 % after 100 cycles at 85 mA g−1. This work provides a valuable design concept for the development of Si/carbon anodes.

Realization of high-capacity coulombic efficiency in sodium alginate/carbon nanotube double network coated Si-anode for lithium-ion batteries

Silicon (Si) is considered as one of the most promising anodes for the next-generation lithium-ion batteries (LIBs) owing to its ultra-high specific capacity, low redox potential and the second abundance of elements in the earth's crust. However, drastic volume change will directly cause electrode pulverization, thus leading to low initial coulombic efficiency (ICE) and terrible cycling stability. In this work, a sodium alginate (SA)‑carbon nanotube (CNT) derived double carbon-coated Si composite (SA-CNT@Si) was prepared through freeze-drying technique followed by high-temperature carbonization, where SA was utilized to encase Si nanospheres, with CNT serving as the conductive framework that interconnects Si spheres. These composites exhibit improved electrical conductivity and stability throughout the charge and discharge cycles when employed as the anodes in LIBs, demonstrating superior electrochemical properties. The SA-CNT@Si electrode with a mass ratio of Si: SA: CNT = 5: 1: 0.75, achieved a first discharge specific capacity of 2200.8 mAh g−1 at a current density of 500 mA g−1 (with the initial three cycles at 100 mA g−1), along with an ICE of 86.2%. Even after 500 cycles, it maintained a capacity of 607 mAh g−1. This study presents a novel approach to designing Si-based anode materials characterized by both high electrical conductivity and structural stability.

Enhanced interface protection of freestanding Si anodes in carbon fiber nanotube by introducing MoO3 buffering layers

Developing Silicon (Si) based flexible and freestanding anodes is crucial for future wearable lithium ion batteries (LIBs) with satisfiable energy density. Improving the poor conductivity and unstable structure of Si in the lithiation/delithiation processes is a significantly important challenge. In this work, we synthesized flexible composites MoO3/Si@CFNT, in which MoO3 as a decorative layer and Si nanoparticles are well encapsulated into carbon fiber nanotube (CFNT). As freestanding lithium ion battery (LIB) anodes, the as-synthesized MoO3/Si@CFNT composites exhibit excellent Li+ storage performance for both half-cell and full-cell (610 mAh g−1 @200 cycles at 0.2 A g−1 for half-cell and 159 mAh g−1 @100 cycles at 0.5 A g−1, with a capacity retention rate of 85.9 % and almost 99 % coulombic efficiency for full-cell). We demonstrated that CFNT reserves sufficient space for the volume change of Si caused by lithiation, meanwhile, the enhanced interface protection of freestanding Si anodes in CFNT was achieved by introducing MoO3 buffering layers. Furthermore, we revealed the ion/electron transport kinetics of MoO3/Si@CFNT flexible electrode by GITT and ex-situ EIS measurements. This work offers a good example and inspiring insights into the design of many other Si based flexible anodes.

Bio-synthesized TiO2 nanoparticles and the aqueous binder-based anode derived thereof for lithium-ion cells.

Titanium dioxide nanoparticles (TiO2-NPs) are a promising anode material for Lithium-ion batteries (LIBs) due to their good rate capability, low cost, non-toxicity, excellent structural stability, extended cycle life, and low volumetric change (∼4%) during the Li+insertion/de-insertion process. In the present paper, anatase TiO2-NPs with an average particle size of ~ 12nm were synthesized via a green synthesis route using Beta vulgaris (Beetroot) extract, and the synthesized TiO2-NPs were evaluated as anode material in LIBs. Furthermore, we employed an aqueous binder (1:1 mixture of carboxy methyl cellulose and styrene butadiene) for electrode processing, making the process cost-effective and environmentally friendly. The results revealed that the Li/TiO2 half-cells delivered an initial discharge capacity of 209.7 mAh g-1 and exhibited superior rate capability (149 mAh g-1 at 20 C) and cycling performances. Even at the 5C rate, the material retained a capacity of 82.2% at the end of 100 cycles. The synthesis route of TiO2-NPs and the aqueous binder-based electrode processing described in the present work are facile, green, and low-cost and are thus practically beneficial for producing low-cost and high-performance anodes for advanced LIBs.

High-conductivity and elasticity interface consisting of Li-Mg alloy and Li3N on silicon for robust Li-ion storage

Silicon (Si) materials are one of the industry's preferred choices for lithium-ion batteries (LIBs) anode in the near and mid-term due to their high theoretical capacity, abundance in earth and safety. However, the weak and low conductivity of the solid electrolyte interface (SEI) leads to poor cycling stability, limited Coulombic efficiency, and poor rate performance, consequently hampering practical applications. Herein, the MgSiN2 functional coating is prepared by in-situ evolution of Mg2Si on porous micro-Si (pMSi@MgSiN2) via a scalable one-step low-temperature nitriding strategy. Interestingly, MgSiN2 is converted into the robust multi-functional interface composed of highly conductive Li3N and elastic Li-Mg alloy during subsequent lithium intercalation, which is studied by in-situ/ex-situ methods. The multi-functional interface takes over the role of improving interfacial stability and ionic/electronic conductivity. As expected, the pMSi@MgSiN2 anode shows a high gravimetric capacity of 1981.5 mAh g−1 at 1.0 A g−1 after 150 cycles, together with a high initial Coulombic efficiency of over 88.4 %. Furthermore, a consider capacity of 894 mAh g−1 can be retained after 500 cycles at 5.0 A g−1. The results and strategy reveal a new route for the integrated design of Si interface or other alloy-type anode materials to the fast lithium storage performance.

Lightweight Carbon-Metal-Based Fabric Anode for Lithium-Ion Batteries.

Lithium-ion battery electrodes are typically manufactured via slurry casting, which involves mixing active material particles, conductive carbon, and a polymeric binder in a solvent, followed by casting and drying the coating on current collectors (Al or Cu). These electrodes are functional but still limited in terms of pore network percolation, electronic connectivity, and mechanical stability, leading to poor electron/ion conductivities and mechanical integrity upon cycling, which result in battery degradation. To address this, we fabricate trichome-like carbon-iron fabrics via a combination of electrospinning and pyrolysis. Compared with slurry cast Fe2O3 and graphite-based electrodes, the carbon-iron fabric (CMF) electrode provides enhanced high-rate capacity (10C and above) and stability, for both half cell and full cell testing (the latter with a standard lithium nickel manganese oxide (LNMO) cathode). Further, the CMFs are free-standing and lightweight; therefore, future investigation may include scaling this as an anode material for pouch cells and 18,650 cylindrical batteries.

Reduced Volume Expansion of Micron-Sized SiOx via Closed-Nanopore Structure Constructed by Mg-Induced Elemental Segregation.

The inherently huge volume expansion during Li uptake has hindered the use of Si-based anodes in high-energy lithium-ion batteries. While some pore-forming and nano-architecting strategies show promises to effectively buffer the volume change, other parameters essential for practical electrode fabrication, such as compaction density, are often compromised. Here we propose a new in situ Mg doping strategy to form closed-nanopore structure into a micron-sized SiOx particle at a high bulk density. The doped Mg atoms promote the segregation of O, so that high-density magnesium silicates form to generate closed nanopores. By altering the mass content of Mg dopant, the average radii (ranged from 5.4 to 9.7 nm) and porosities (ranged from 1.4 % to 15.9 %) of the closed pores are precisely adjustable, which accounts for volume expansion of SiOx from 77.8 % to 22.2 % at the minimum. Benefited from the small volume variation, the Mg-doped micron-SiOx anode demonstrates improved Li storage performance towards realization of a 700-(dis)charge-cycle, 11-Ah-pouch-type cell at a capacity retention of >80 %. This work offers insights into reasonable design of the internal structure of micron-sized SiOx and other materials that undergo conversion or alloying reactions with drastic volume change, to enable high-energy batteries with stable electrochemistry.

Heterostructured ZnS/Co embedded in pinecone-like N/S-doped carbon for efficient sodium/lithium storage

Constructing heterogeneous electrodes to confront various electrochemical and structural requirements is demonstrated to be crucial for improving the sodium and lithium storage performances. Herein, a novel design of ZnS/Co heterostructures is expounded with abundant phase boundaries encapsulated in highly-conductive N/S-doped “pinecone”-like carbon framework (ZnS/Co@NSC-450) as a superior anode for sodium ion batteries (SIBs) and lithium-ion batteries (LIBs). In ZnS/Co@NSC-450, the ZnS/Co heterostructures can improve the electronic conductivity of material and stabilize the electrode structure integrity during cycling, while the N/S-doped “pinecone”-like carbon is beneficial for alleviating the volume expansion effect of active materials, providing additional active sites for sodium/lithium storage and ensuring the rapid electron/ion transfer across the electrode. Due to the synergistic effect of multiple components, both the SIBs and LIBs with ZnS/Co@NSC-450 anodes exhibit high-rate capability (476 mAh g−1 at 6.4 A g−1 for SIBs and 387 mAh g−1 at 12.8 A g−1 for LIBs) and outstanding long-term cycling stability (557 mAh g−1 at 2 A g−1 for SIBs after 1500 cycles and 767 mAh g−1 for LIBs after 1000 cycles). These results disclose the promising potential of ZnS/Co@NSC-450 toward high-performance SIBs and LIBs.

Engineering of Cerium Modified TiNb2O7 Nanoparticles For Low-Temperature Lithium-Ion Battery.

Although TiNb2O7 (TNO) with comparable operating potential and ideal theoretical capacity is considered to be the most ideal replacement for negative Li4Ti5O12 (LTO), the low ionic and electronic conductivity still limit its practical application as satisfactory anode for lithium-ion batteries (LIBs) with high-power density. Herein, TNO nanoparticles modified by Cerium (Ce) with outstanding electrochemical performance are synthesized. The successful introduction of Ce3+ in the lattice leads to increased interplanar spacing, refined grain size, more oxygen vacancy, and a smaller lithium diffusion barrier, which are conducive to improve conductivity of both Li+ and electrons. As a result, the modified TNO reaches high reversible capacity of 256.0mAhg-1 at 100mAg-1 after 100cycles, and 183.0mAhg-1 even under 3200mAg-1. In particular, when the temperature drops to -20°C, the cell undergoing 1500cycles at a high current density of 500mAg-1 can still reach 89.7mAhg-1, corresponding to a capacity decay rate per cycle of only 0.033%. This work provides a new way to improve the electrochemical properties of alternative anodes for LIBs at extreme temperature.

Defect Engineering Boosting High‐Performance Graphite Anode for Sodium‐Ion Batteries in Ether‐Based Electrolytes

Sodium‐ion batteries (NIBs) as one of the next‐generation energy storage devices are gradually used in energy field and entering lithium‐ion batteries (LIBs) market. Graphite with low price exhibits excellent Li+ reversible intercalation properties, which has been widely applied in anodes of LIBs. But it has low capacity for sodium because of its weak chemical bonding with sodium. Here, a defect engineered graphite with low graphitization structure is reported. This graphite demonstrates a defect adsorption and solvated ion intercalation of sodium ions by introducing more active sites and ether electrolytes, effectively improving the storage capacity of sodium. Further experiments and characterization show defects increased after ball milling with surface area increased, and the favorable defects on the interface of graphite are significantly increased. The defect engineered graphite absorbs more sodium‐ions and exhibits capacitive characteristics with fast sodiation/desodiation process, leading to an improved capacity storage than the defect‐free graphite. Meanwhile, the defect engineered graphite can deliver a capacity of 175 mAh g−1, and maintain a good capacity retention of 84% at 5 A g−1 after 6000 cycles. This work discovers a general methodology to obtain defect engineered graphite, which will provide an experimental strategy to achieve large‐scale industrialization for low‐cost NIBs.

Cobalt vacancy boosting Co3-xO4@C with superior pseudocapacitive lithium storage

The Co3O4 as anode for lithium ion batteries (LIBs) suffers the sluggish electrode kinetics and severe capacity fade during the cycles. The defective engineering of Co3O4 with oxygen/cobalt defects is an effective strategy to optimize Co3O4 with enhanced electrochemical properties. Herein, a series of 3D inter-connected Co3-xO4@C-y nanostructures with abundant Co defects are synthesized through a hydrothermal approach with subsequent heating-controlled process. Benefiting from its rich surface cobalt-defective sites and the 3D interconnected frameworks, as well as its high surface area and residual carbon layer, the Co3-xO4@C-y synthesized at y = 400 °C as anode for LIBs displays superior pseudocapacitive lithium storage properties with an ultra-high reversible specific capacity of 1900.7 mAh g−1 at 0.2 A g−1, excellent rate capability (e.g., 1415.1 mAh g−1 at 10 A g−1) and ultra-long cycling stability (e.g., 1160.5 mAh g−1 at 15 A g−1 after 2000 cycles).

Large-Scale Synthesis of Highly Porous CuO/Cu2O/Cu/Carbon Derived from Aerogels for Lithium-Ion Battery Anodes.

In this work, an effective strategy for the large-scale fabrication of highly porous CuO/Cu2O/Cu/carbon (P-Cu-C) has been established. Cu-cross-linked aerogels were first continuously prepared using a continuous flow mode to form uniform beads, which were transformed into P-Cu-C with a subsequent pyrolysis process. Various pyrolysis temperatures were used to form a series of P-Cu-C including P-Cu-C-250, P-Cu-C-200, P-Cu-C-350, and P-Cu-C-450 to investigate suitable pyrolysis conversion processes. The obtained P-Cu-C series were utilized as anodes of lithium-ion batteries, in which P-Cu-C-250 exhibited a higher reversible gravimetric capacity, excellent rate capability, and superior cycle stability. The enhanced behavior of P-Cu-C-250 was benefitted from the synergistic interaction between uniformly dispersed CuO, Cu2O, Cu nanoparticles, and highly graphitized carbon with a large surface area and highly porous structure. More importantly, the preparation of P-Cu-C-250 could be scaled up by taking advantage of the continuous flow synthesis mode, which may provide pilot- or industrial-scale applications. The large-scale fabrication proposed here may give a universal method to fabricate highly porous metal oxide-carbon anode materials for electrochemical energy conversion and storage applications. Porous CuO/Cu2O/Cu/carbon derived from Cu-crosslinked aerogels was used as Li-ion battery anode materials, exhibiting a high reversible areal capacity, large gravimetric capacity, superior cycling performance, and excellent rate capacity. A continuous preparation method is established to ensure the product scaled up.

Enhanced diffusion kinetics in Y-doped SnO2 anodes for low-temperature lithium-ion batteries: A combined theoretical and experimental study

In recent years, there has been an increasing demand for lithium-ion batteries suitable for low temperatures in various fields. SnO2, with its high theoretical specific capacity, has emerged as an ideal candidate for low-temperature lithium-ion batteries. However, tin oxide exhibits inherent issues such as poor conductivity and limited cycle reversibility. Enhancing the diffusion rate of lithium ions in tin oxide is crucial for improving its low-temperature performance. We use first-principles calculations based on Density Functional Theory (DFT) to investigate the doping models of various transition metal elements (Sc, Y, Ti, Zr, V, Nb, Gr, Mo, Mn, Fe, Co, Ni) with a rational ratio of 4 % in SnO2. The results indicate that Y doping decreases the band gap of SnO2 by 0.253 eV, leading to a significant reduction in the Li-ion diffusion barrier of α-Sn. Furthermore, the synthesized SnO2 doped with Y (Y-SnO2) electrode exhibited excellent cyclic stability as an anode and achieved a high reversible capacity of 672 mAh g−1 at −10°C, surpassing that of the pure SnO2 (450 mAh g−1). Moreover, it demonstrated a higher diffusion coefficient of lithium ions and lower charge transfer impedance at both low and room temperatures.