Anode For Batteries Research Articles

Regulating the active hydroxyl group of starch: Revealing the evolution of hard carbon structure and sodium storage behavior

The active hydroxyl group of starch has a crucial effect in regulating the microstructure of hard carbon anodes for sodium-ion batteries. By optimizing the chemical structure of starch and controlling the pyrolysis process, high-performance hard carbon materials can be obtained. These active hydroxyl groups are primarily located on the terminal and ring structures of glucose units, exerting significant influence on the formation and performance of hard carbon. Our results demonstrate that low-temperature oxidation treatment effectively modifies the terminal hydroxyl groups in precursor materials, facilitating chain cross-linking and leading to a more robust hard carbon structure. This cross-linking effect helps suppress excessive foaming during pyrolysis, thereby enhancing the stability of the hard carbon structure. Furthermore, by modifying the hydroxyl group on the ring structure of precursors, we can control the pyrolysis process, promote pore closure, and further improve the low plateau capacity of hard carbon anode materials from 153.95 to 219.58 mAh g −1. This study offers novel insights into harnessing and understanding starch's active hydroxyl groups in preparing hard carbon materials—a significant contribution towards optimizing their performance as anode materials.

Controllable preparation of carbon coating Ge nanospheres with a cubic hollow structure for high-performance lithium ion batteries

Germanium based nanomaterials are very promising as the anodes for the lithium ion batteries since their large specific capacity, excellent lithium diffusivity and high conductivity. However, their controllable preparation is still very difficult to achieve. Herein, we facilely prepare a unique carbon coating Ge nanospheres with a cubic hollow structure (Ge@C) via a hydrothermal synthesis and subsequent pyrolysis using low-cost GeO2 as precursors. The hollow Ge@C nanostructure not only provides abundant interior space to alleviate the huge volumetric expansion of Ge upon lithiation, but also facilitates the transmission of lithium ions and electrons. Moreover, experiment analyses and density functional theory (DFT) calculations unveil the excellent lithium adsorption ability, high exchange current density, low activation energy for lithium diffusion of the hollow Ge@C electrode, thus exhibiting significant lithium storage advantages with a large charge capacity (1483 mAh/g under 200 mA g−1), distinguished rate ability (710 mAh/g under 8000 mA g−1) as well as long-term cycling stability (1130 mAh/g after 900 cycles under 1000 mA g−1). Therefore, this work offers new paths for controllable synthesis and fabrication of high-performance Ge based lithium storage nanomaterials.

Nucleation, growth and dissolution of Li metal dendrites and the formation of dead Li in Li-ion batteries investigated by operando electrochemical liquid cell scanning transmission electron microscopy

Li metal dendrites, which can form on the anode of Li-ion batteries during charging, not only accelerate their aging but may also pose a safety hazard when causing a short-circuit within the battery. Therefore, a fundamental understanding of the mechanisms governing the early stages of Li plating, the progression into dendrites, and the formation of dead Li, is imperative. Here, we employ operando electrochemical liquid cell scanning transmission electron microscopy (ec-LC-STEM) to monitor, in real-time, nanoscale processes occurring at the anode-electrolyte interface of a Li-ion battery during charge/discharge. Our results indicate that Li metal dendrites nucleate as spherical Li nanoparticles beneath the solid electrolyte interphase (SEI) and subsequently grow until dendritic Li metal is formed. During discharge, Li dendrites undergo incomplete dissolution, leading to the formation of dead Li. Interestingly, the SEI layers play a pivotal role in both the growth and the dissolution processes. Our findings reveal that the growth of Li dendrites is a multi-step process: (i) nucleation, (ii) root growth, and (iii) tip growth. We elucidate that the formation of dead Li is associated with the morphology of the initially developed dendrites and the structure of the SEI layer. The thinning of the inhomogeneously thick Li whiskers leads to the contraction of the root before the tip, ultimately resulting in the creation of electrically isolated Li metal. This work sheds light on dendritic Li growth as well as on the formation of dead Li and provides significant insights for future electrode designs.

Dual plating zinc foam of three-dimensional reconstruction as a high-flux and stable zinc metal anode for aqueous zinc-ion batteries

The practical utilization of zinc-metal anodes is primarily hindered by the restricted lifespan and diminished Coulombic efficiency (CE) arising from the growth of zinc dendrites and concurrent side reactions. To tackle these challenges, numerous 3D hosts have been thoroughly investigated, although there is still a need to address concerns related to high-flux deposition and electrode corrosion resistance. In a pioneering effort, a double-coated material derived from foamed zinc (denoted as FZn@Cu) has been developed for utilization as an anode in high-performance zinc-metal batteries. FZn@Cu originates from a three-dimensional reconstruction of a zinc electrode (foam Zn) in a porous and layered structure with a dense Cu coating on the surface and a solid CuZn5 at the interface. Experimental observations, density-functional theory calculations and phase-field simulations indicate that zincphilic Cu and CuZn5 can induce homogeneous deposition of Zn. The results show that FZn@Cu has low voltage hysteresis (25.1 mV), long cycling stability (exceeding 1800 h) and the ability to inhibit electrode corrosion. In addition, the full cell based on FZn@Cu composite anode and MnO2 cathode exhibits excellent multiplicity performance and stable cycle life (133.9 mAh g−1 at 1 A g−1 after 1000 cycles). This study introduces an innovative and scalable zinc-based anode material, offering a new strategy for the design of dendrite-free zinc anodes.

Preparation of biochar from pyrolysis of soybean straw at different pyrolysis temperature for cadmium removal from wastewater and pyrolysis gas investigation

The Cd2+ adsorption performance of biochar derived from soybean straw pyrolysis at 400–600 °C is investigated. Langmuir model can accurately describe the Cd2+ adsorption data with adsorption amount of 47.30 mg/g with pH=5. Cd2+ adsorption kinetic process could be analyzed using Pseudo-second-order. Biochar has large Cd2+ wastewater treatment volume, based on column adsorption experiment. The π-electrons play an important role in Cd2+ adsorption, based on adsorption mechanism analysis. Biochar has good stability after three cycles. Biochar also has good application potential used in lithium ion battery anode with specific capacity of 132 mA g−1. Besides, pyrolysis gas is recycled in the preparation process of biochar with heating value of the 12.10 MJ/Nm3. These results indicate that soybean straw waste is converted into sustainable adsorbent for Cd2+ wastewater treatment.

Metallic MoS2 grown on CNT as high performance anodes for lithium-ion batteries

To mitigate the structural collapse of MoS2 during charging and discharging, MoS2-CNT composites were fabricated as anodes for lithium-ion batteries (LIBs). Hydroxylation CNT was incorporated to provide growth sites for MoS2 nanosheets, thereby enhancing their overall dispersion. This structure effectively improves the stability during cycling compared to MoS2/CNT, and to some extent improves the structural collapse of MoS2. As a result, the initial discharge capacity of the MoS2-CNT anode was 1194 mAh g−1 and the sustained capacity was 774 mAh g−1 after 200 cycles at 0.5 A g−1.

Constructing Si@CN@MXene from silicon waste as high-performance lithium-ion battery anodes

Silicon represents one of the most attractive materials for anodes in lithium-ion batteries (LIBs) due to highest theoretical specific capacity. Thus, there is a most urgent need to prepare Si-based nano materials in a very efficient way, and develop some reasonable approaches for their modification in order to resolve the short-falls of Si anode, which include both low conductivity and huge volume changes during intercalation of lithium ions. In this work, the kerf loss silicon (KL Si) from the photovoltaic industry has been used as an inexpensive Si source for the synthesis of the Si@CN@MXene (SCM) composite to be applied as an anode material. Meanwhile, the chitosan works as the charge bridge in sequence with the Si and MXene nanosheets under electrostatic force during composite preparation. The MXene nanosheet and N-doped carbon layer that build up during chitosan calcination can be attributed to forming a hierarchical high-speed conductive network over the surface of silicon, which contributed to alleviate the volume expansion of silicon. The SCM electrode discharge capacity was obtained at a stable value of 900.8 mAh g−1 at 0.5 A g−1, 861.9 mA g−1 at 1 A g−1 and 657.6 mA g−1 even at 2 A g−1 after 100 cycles. The SCM electrode also exhibited good rate performance from 0.2 to 5 A g−1. Therefore, this study recommends that the method is very promising for producing the silicon anode material for LIBs from KL Si.

Construction of 2D/1D rGO/H2Ti3O7 composite as anode for high performance lithium-ion batteries

Ultrafine one-dimensional (1D) H2Ti3O7 nanowires were prepared by a hydrothermal reaction with high concentration of KOH as base source. Then 2D/1D rGO/H2Ti3O7 architecture was constructed and investigated as the anode material for lithium-ion batteries. Benefiting from the addition of rGO nanosheets and the retention of ultrafine 1D H2Ti3O7 nanowires, the rGO/H2Ti3O7 electrode presented superior electrochemical performance with excellent rate capability, long cycling stability and high capacity in half cells. It delivered high reversible capacities of 274 mAh g−1 at 0.1 A g−1 and 163 mAh g−1 at 1 A g−1, as well as a long-term cycling performance (259.3 mAh g−1 at 0.2 A g−1 after 1000 cycles). The excellent electrochemical performance of the composite can be attributed to the unique architecture with smaller diameter of 1D H2Ti3O7 nanowires and conductive rGO nanosheets to shorten the transmission distance of electrons and Li+ and improve the electrical conductivity in rGO/H2Ti3O7 composite.

Boosting anion-cation coordination by anti-solvents towards durable hydrous organic zinc batteries

Hydrated fluoroborates offer excellent nonflammability and their spontaneous hydrolysis can generate a ZnF2-based solid electrolyte interphase (SEI) on Zn anodes in hydrous organic Zn batteries. However, uncontrolled hydrolysis can lead to thick and uneven SEI, as well as cathode collapse. Here, we propose using anti-solvents to regulate the hydrolysis of fluoroborate anions via facilitating anion-cation coordination, resulting in a thin but compact ZnF2 SEI. Consequently, Zn anodes maintain stable cycling for over 1400 h at 1 mA cm−2, a high Coulombic efficiency (CE) of 99.4 % and high-rate capability up to 15 mA cm−2. Even at a challenging temperature of 60 °C, the Zn anode demonstrates over 1000 h of stable cycling with a CE of 98.0 %. Furthermore, the modified electrolyte alleviates V2O5 cathode dissolution, enabling extended cycling lifespan with a high CE close to 100 % in Zn||V2O5 full cells at room and high temperatures. Our findings suggest an avenue toward electrolyte design for developing high-performance Zn batteries and beyond.

Rechargeable Self-Powered pressure sensor based on Zn-ion battery with high sensitivity and Broad-Range response

Flexible pressure sensors find broad applications in electronic skin, human–computer interaction, and health monitoring. However, developing self-powered flexible sensors capable of detecting both dynamic and static pressures with high sensitivity and a wide detection range remains a significant challenge. Here, we report the design and fabrication of a new rechargeable Zn-ion battery-type flexible self-powered pressure sensor (RZIB-FPS). In the device, the anode of a flexible Zn-ion battery is designed into a sandwich configuration with a porous isolation layer in between a conductive layer decorated with polymethylmethacrylate microspheres and a flexible Zn electrode. The self-powered pressure sensing mechanism relies on the variation in output voltage resulting from the resistance change of the anode when subjected to external pressure. This RZIB-FPS exhibits an open-circuit voltage of 1.46 V, an energy density of 392 µWh cm−2, a high sensitivity (up to 42.6 mV kPa−1), a wide pressure detection range (up to 330 kPa), and excellent cycling stability (up to 12,000 cycles). Furthermore, the proposed all-in-one device design demonstrates excellent charge–discharge performance, manifesting its high integration level and potential for sensor miniaturization. This study introduces a new strategy for developing high-performance sensors for future self-powered smart wearable electronics.

MOFite: A High-Density Lithiophilic and Scalable Metal-Organic Framework Anode for Rechargeable Lithium-Ion Battery.

Developing an anode material that has better performance efficiency than commercial graphite while keeping the features of economic scalability and environmental safety is highly desirable yet challenging. MOFs are a promising addition to the ongoing efforts, however, the relatively poor performance, chemical instability, and large-scale economic production of efficiency-proven pristine MOFs restrict their utility in real-life energy storage applications. Furthermore, hierarchical porosity for lucid mass diffusion, high-density lithiophilic sites are some of the structural parameters for improving the electrode performance. Herein, we have demonstrated the potential of economically scalable salicylaldehydate 3D-conjugated-MOF (Fe-Tp) as a high-performance anode in Li-ion batteries: the anode-specific capacity achieved up to 1447 mA h g-1 at 0.1 A g-1 and 89% of cyclic stability after 500 cycles at 1.0 A g-1.for pristine MOF. More importantly, incorporating 10% Fe-Tp doping in commercial graphite (MOFite) significantly enhanced lithium storage, doubling capacitance after 400 cycles. It signifies the potential practical utility of Fe-Tp as a performance booster for commercial anode material.

Tandem desolvation effect enables highly reversible Zn metal anodes

Metallic Zn, with its affordability and safety, has been regarded as an attractive anode for aqueous batteries but has suffered from dendrite growth. Here, a tandem desolvation strategy is proposed to stabilize Zn metal anodes by a 4-pyridinecarboxamide (PCA) additive as an example. Theoretical and experimental characterizations demonstrate that the PCA molecular layer adsorbs on the anode surface, as well as the derived ZnS/N-rich solid electrolyte interphase (SEI), can sequentially promote the desolvation of hydrated Zn2+ during the electrodeposition process. This phenomenon, known as the tandem desolvation effect, effectively suppresses Zn dendrite growth and achieves the highest utilization rate of 96.7 % in the Zn||Zn cells. Specifically, the Zn||Zn cells can operate at 10, 20, and 50 mA cm−2 with a deposition capacity of 17 mAh cm−2 for 1200, 1000, and 850 h, respectively. Additionally, the constructed PANI||Zn pouch cells also achieve excellent cycle performance, confirming the feasibility of the tandem desolvation effect. This work enriches the understanding of Zn electrodeposition and provides a new perspective for the development of highly reversible metal anodes.

Controlled morphology significantly enhances electrochemical performance of LaNiO3-NiO anodes for Li-ion batteries

Traditional graphite anodes have become increasingly reliable in lithium-ion battery applications. However, there is an urgent need to overcome their limitations, such as the low theoretical capacity and less favorable rate performance. Recently, perovskite-type oxides have garnered increasing attentions as anodes owing to their advantages of capacity, rate performance, lifespan, and safety. In our previous study, the electrochemical performance of LaNiO3-NiO nanoparticles was enhanced compared to those of LaNiO3, primarily thanks to the synergistic effect of the biscuit-shaped LaNiO3-NiO and graphene-like layered g-C3N4. Morphology modulation is an important method for enhancing the performance of the anode materials. Based on this concept, we designed two kinds of LaNiO3-NiO with different morphologies (micro-sphere and micro-flower), and tested their physical and electrochemical properties. The discharge capacity of the LaNiO3-NiO micro-sphere anode was 714.5 mAh g-1 after 950 cycles at 1000mAg-1, which is significantly higher than those of LaNiO3-NiO micro-flower and nanoparticle. However, the LaNiO3-NiO Micro-flower anode maintains a reversible capacity of 144.2 mAh g-1 at 10.0Ag-1, which is higher than that of the LaNiO3-NiO Micro-sphere electrode (125.8 mAh g-1). It was found that the morphology modification endows the electrodes possessing their own outstanding electrochemical properties.

One-step fabrication of binder-free nanoSi-CNT-carbon black/cyclized PAN composite anode for high-performance lithium-ion batteries

Silicon is one of the most promising anode materials for lithium-ion batteries (LIBs) due to its high theoretical capacity. However, its non-conductive nature and significant volume expansion during lithiation pose challenges. In this study, we developed a novel electrode comprising silicon nanoparticles (nanoSi), carbon nanotubes (CNTs), and carbon black (CB) in cyclized polyacrylonitrile (cPAN), referred to as nanoSi-CNT-CB/cPAN. This electrode is fabricated through a one-step thermal process by heating a cast nanoSi-CNT-CB/PAN film on Cu foil at 310 °C. The LIB performance using the nanoSi-CNT-CB/cPAN electrode shows an impressive initial coulombic efficiency of 93.1 % at 0.1 A g−1, a high specific capacity of 2267.2 mAh g−1 at 0.5 A g−1, and a retention of 89.2 % over 390 cycles, achieving 783 mAh g−1 at 5 A g−1. We attribute these results to the fused cPAN, which provides good adhesion to nanoSi, CNTs, CB, and Cu foil, acting as a binder, active material, and ionic conductive medium. The well-dispersed CNTs and CB form an effective conductive network in the electrode. Additionally, the one-step electrode fabrication is a simple and cost-effective process for next-generation Si-based LIBs.

Revealing the sodium storage mechanism of cellulose separator-derived hard carbon anode materials for sodium-ion batteries

Hard carbon (HC) shows significant promise as a material for sodium-ion batteries (SIB). Cellulose-derived carbon is considered one of the most promising high-performance anode materials for sodium-ion batteries. In this study, waste cellulose separator-derived HC anode materials were rationally developed using the pre-oxidation-carbonization pyrolysis method. The as-prepared HC possessed advantageous characteristics for Na+ storage, including a unique fibrous structure, a reasonable space layer, and a small specific surface area (SSA). The optimal sample demonstrated a substantial reversible capacity of 361.29 mAh/g at 0.1C, an impressive high-rate performance with a reversible capacity of 272.93 mAh/g at 10C, and an initial coulombic efficiency of 84.85 %. Following 500 cycles at 1C, the capacity retained 96.38 % of its initial value. The sodium storage process was identified as the “adsorption-insertion-pore filling mechanism” through ex-situ XRD and in-situ Raman experiments. Moreover, the as-prepared HCs demonstrated better rate and cycle capability when evaluated as anodes in full-cell sodium-ion batteries (SIBs). This research provides valuable insights into the rational design of high-performance HC anodes for SIBs and other applications.

Two-dimensional metallic Be2Al monolayer as a potential anode material for lithium-ion/sodium-ion batteries

Developing anode materials that combine excellent robustness, high-volume capacity, and superior electrical conductivity is essential for advancing high-performance ion batteries. Through comprehensive first-principles calculations, this paper illustrates the possibility of a two-dimensional Be2Al monolayer as an anode candidate for lithium/sodium-ion batteries. The Be2Al monolayer exhibits a high theoretical energy storage capacity (2382/2382 mAh/g for Li/Na) and an ultra-low diffusion barrier (124/77 meV for Li/Na). Its average open-circuit voltage (0.35/0.52 V for Li/Na) falls within the desired ideal range. Additionally, the Be2Al monolayer demonstrates excellent electrical conductivity, facilitating efficient electron transport. These promising outcomes indicate that the Be2Al monolayer can be an effective anode for next-generation lithium-ion and sodium-ion batteries.

Electroplating of zinc onto polyelectrolyte complex membranes as anode for aqueous zinc-ion batteries

Conventionally, the anode of a primary Aqueous zinc-ion batteries (ZIBs) is metallic and rigid, which made it difficult to integrate into flexible designs. In this research, a composite polyelectrolyte complex (PEC) with cationic poly(diallyldimethylammonium chloride), anionic poly(sodium-4-styrenesulfonate) and carbon black (CB) as conductive filler (PEC-CB) was developed as an anode substrate for zinc deposition via electroplating technique. The Zinc-electroplated PEC-CB (Zn-PEC-CB) anode was characterized using electron microscopy and X-Ray diffraction analysis to verify the successful zinc coating. The Zn-PEC-CB was then assembled with PEC-CB-MnO cathodes in an ZIB setup. The results demonstrated the potential of PEC-based electrodes as a promising alternative to conventional materials in ZIBs, encouraging further exploration in energy storage applications.

Facile synthesis of novel bismuth oxide/bismuth molybdate nanocomposites as advanced anodes for high performance Li‐ion batteries

In this study, a novel nanocomposite material consisting of Bi2O3 and Bi2MoO6, named as Bi2O3@Bi2MoO6, was successfully fabricated by co-precipitation method in ethylene glycol solvent. Morphological analysis of the heat-treated sample at 400 oC for 12 h in Ar atmosphere (Bi2O3@Bi2MoO6 _400oC) showed that it contained nano-sized particles of Bi2O3 and Bi2MoO6; in addition, an amorphous phase along with a crystalline structure was also observed. When used as an anode for Li-ion batteries (LIBs), Bi2O3@Bi2MoO6 _400oC anode exhibits excellent electrochemical properties such as high Coulombic efficiency, high specific capacity, excellent capacity retention, and outstanding rate capacity. Specifically, the Bi2O3@Bi2MoO6 _400oC anode presented a reversible capacity of 786 mAh g-1 at the beginning cycle at 0.1 A g-1 and retained about 90% of the charging capacity value after 80 cycles. The advanced electrochemical properties of the nanocomposite anode are related to the combination of many aspects such as nanostructure, existence of amorphous phase, and pseudo-behaviour of metal-based components. The structural stability and electrochemical performance of the anode material, therefore, are improved. These results demonstrate Bi2O3@Bi2MoO6 _400oC as a promising material for establishing high-performance LIB anodes.

Unraveling the origin of the high reversibility in entropy-stabilized rocksalt-type (Mg0.2Co0.2Mn0.2Ni0.2Zn0.2)O anodes for lithium-ion storage

Entropy-stabilized rocksalt-type oxides, composed of multiple components, are increasingly recognized as highly promising materials for energy storage applications. In this study, a novel anode material, (Mg0.2Co0.2Mn0.2Ni0.2Zn0.2)O, demonstrates exceptional reversible specific capacity of 773.4 mAh g−1 even after 200 cycles at 0.1 A g−1. Density functional theory (DFT) analysis reveals superior electrical conductivity of (Mg0.2Co0.2Mn0.2Ni0.2Zn0.2)O compared to individual oxides like CoO, which has the potential to enhance electronic transfer to improve electrochemical performance. In situ transmission electron microscopy (TEM) observations confirm the reversible crystal structure of rocksalt-type (Mg0.2Co0.2Mn0.2Ni0.2Zn0.2)O anodes, with only ∼36.8 % volume expansion in four cycles. This investigation offers insights into the (de)lithiation process at a microscopic scale, shedding light on the origins of high reversibility and guiding the design of future high-entropy materials. Entropy-stabilized rocksalt-type (Mg0.2Co0.2Mn0.2Ni0.2Zn0.2)O oxides exhibit excellent properties, positioning them as promising candidates for lithium-ion batteries (LIBs) anode materials.

Graphene oxide synthesis from coconut fiber powder using triple superphosphate catalyst and its potency for secondary battery electrode

Coconut fiber, considered an organic waste, emerges as a promising alternative carbon source for graphene oxide production—a material characterized by its conductive nature due to oxidation and the introduction of functional groups. The synthesis process involves carbonization with varied holding times (10, 20, and 30 minutes) and the utilization of Triple Superphosphate (TSP) and Ferrocene catalysts at concentrations of 10 wt.% and 20 wt.%. Subsequently, the sonication method is employed to enhance the electrical conductivity of graphene oxide post-carbonization. Notably, the electrical conductivity tests, conducted using a sourcemeter, revealed the optimum performance at 20 minutes of carbonization duration and a 20 wt.% TSP catalyst concentration, yielding an impressive electrical conductivity of 11,489.86 S/m. These findings underscore the significance of tailored parameters in optimizing graphene oxide synthesis for applications such as high-conductivity battery anodes.