High-performance Lithium-ion Battery Anodes Research Articles

Microwave-assisted upcycling of plastic waste to high-performance carbon anode for lithium-ion batteries

The increasing demand for high-performance lithium-ion batteries (LIBs) has emphasized the need for affordable and sustainable materials, prompting the exploration of waste upcycling to address global sustainability challenges. In this study, we efficiently converted polypropylene (PP) plastic waste from used centrifuge tubes into activated polypropylene carbon (APC) using microwave-assisted pyrolysis. The synthesis of APC was optimized using response surface methodology/central composite design (RSM/CCD). Based on the RSM results, the optimal conditions for PP plastic conversion into carbon were determined as follows: HNO3 concentration of 3.5 M, microwave temperature of 230 °C, and holding time of 25 min. Under these conditions, the obtained intensity ratio of Id/Ig in PP carbon was 0.681 ± 0.013, with an error of 6.81 ± 0.013 % between predicted and actual values. The physicochemical studies, including FESEM-EDX, XRD, and Raman spectroscopy, confirmed the successful synthesis of APC samples. The APC 800 material exhibited a well-organized three-dimensional structure characterized by large pores and mesopores, enabling fast ion transport in the electrode. As a result, the APC 800 electrode demonstrated an initial discharge capacity of 381.0 mAh/g, an improved initial coulombic efficiency of 85.1%, and excellent cycling stability after 100 cycles. Notably, the APC 800 electrode displayed remarkable rate performance, showing a reversible capacity of 355.1 mAh/g when the current density was reset to 0.2 A/g, highlighting its high electrochemical reversibility. The outstanding characteristics of APC 800 as an anode electrode material for high-performance lithium-ion batteries suggest a promising future for its application in the field.

Dynamic hydrogen bond cross-linking binder with self-healing chemistry enables high-performance silicon anode in lithium-ion batteries

The structure instability and cycling decay of silicon (Si) anode triggered by stress buildup hinder its practical application to next-generation high-energy–density lithium-ion batteries (LIBs). Herein, a cross-linking polymeric network as a self-healing binder for Si anode is developed by in situ polymerization of tannic acid (TA) and polyacrylic acid (PAA) binder labelled as TA-c-PAA. The branched TA as a physical cross-linker complexes with PAA main chains through abundant dynamic hydrogen bonds, endowing the cross-linking TA-c-PAA binder with unique self-healing property and strong adhesion for Si anode. Benefiting from the mechanical robust and hard adhesion, the Si@TA-c-PAA electrode exhibits high reversible specific capacities (3250 mAh/g at 0.05C (1C = 4000 mA g−1)), excellent rate capability (1599 mAh/g at 2C), and impressive cycling stability (1742 mAh/g at 0.25C after 450 cycles). After Ex situ morphology characterization, in situ swelling analysis, and finite element simulation, it is found that the TA-c-PAA binder allows the Si anode to dissipate stress and prevent pulverization during lithiation and delithiation, thus the hydrogen bonds among interpenetrating network may be adaptable to the stress intensity. Our work paves a new avenue for the design of efficient and cost-effective binders for next-generation Si anode in LIBs.

A feasible recycling route for spent graphite: Microwave-assisted puffing with Fe2O3 loading to construct high-performance anode for lithium-ion batteries

Nowadays, one of the important issues associating with the lithium-ion battery industry is to address the inefficient utilization of spent graphite from plenty of spent batteries. Conventional methods including discarding or burning will exacerbate the environmental risks, which calls for novel routes to optimize the recycling of spent graphite. This study proposes a novel recycling strategy for spent graphite to construct Fe2O3@microwave-puffed graphite (Fe2O3@MPG) composite anode for high-capacity lithium storage. By means of mild intercalation followed by microwave treatment, spent graphite is converted to puffed graphite which can be used as framework for loading Fe2O3 to form Fe2O3@MPG with sandwich structure. This sandwich structure can provide conductive networks and channels to enhance conductivity and Li ions transfer, as well as confine Fe2O3 in microwave-puffed graphite framework to ease the structural instability caused by the volume change of Fe2O3, thereby endowing the Fe2O3@MPG composite with superior rate performance, high capacity, and excellent structural stability. The Fe2O3@MPG electrode possesses a specific capacity of 1100 mAh g−1 at 200 mA g−1, exhibits excellent rate performance with a capacity of 632 mAh g−1 at 2000 mA g−1, and delivers an outstanding cycling performance for 500 cycles. This study not only provides an important method for the efficient recycling of spent graphite but develops a universal method for modifying transition metal oxides anode utilizing spent graphite, thereby promoting the closed-loop lifecycle of graphite and the resource sustainability in the LIBs industry.

Growth of Vertical Graphene Sheets on Silicon Nanoparticles Well-Dispersed on Graphite Particles for High-Performance Lithium-Ion Battery Anode.

With rapidly increasing demand for high energy density, silicon (Si) is greatly expected to play an important role as the anode material of lithium-ion batteries (LIBs) due to its high specific capacity. However, large volume expansion for silicon during the charging process is still a serious problem influencing its cycling stability. Here, a Si/C composite of vertical graphene sheets/silicon/carbon/graphite (VGSs@Si/C/G) is reported to address the electrochemical stability issues of Si/graphite anodes, which is prepared by adhering Si nanoparticles on graphite particles with chitosan and then in situ growing VGSs by thermal chemical vapor deposition. As a promising anode material, due to the buffering effect of VGSs and tight bonding between Si and graphite particles, the composite delivers a high reversible capacity of 782.2mAhg-1 after 1000 cycles with an initial coulombic efficiency of 87.2%. Furthermore, the VGSs@Si/C/G shows a diffusion coefficient of two orders higher than that without growing the VGSs. The full battery using VGSs@Si/C/G anode and LiNi0.8Co0.1Mn0.1O2 cathode achieves a high gravimetric energy density of 343.6Whkg-1, a high capacity retention of 91.5% after 500 cycles and an excellent average CE of 99.9%.

Three-dimensional graphitic hierarchical porous carbon-supported SnOx@nitrogen-doped carbon composite as high-performance lithium ion battery anode material

Utilizing tin and its oxides (SnOx, x = 0/1/2) as anode confront the main problems like large volume expansion and poor electrical conductivity during cycling. As an efficient solution, a three-dimensional (3D) graphitic hierarchical porous carbon (HPC) with highly fluffy structure was employed as a support for fabrication of HPC/SnOx@nitrogen-doped carbon (NC) composite. The resulting HPC/SnOx@NC composite presented an effective dual‑carbon confinement structure with 3D conductive network and high-quality carbon coatings. The unique structure played significant roles in restricting the expansion of Sn and its oxides as well as enhancing their ion/electron transport efficiency. The as-prepared composite exhibited a maintained reversible specific capacity of 644 mAh g−1 after 200 cycles at 1000 mA g−1. In addition, it presented a high specific capacity of 1458 mAh g−1 at 100 mA g−1 and 858 mAh g−1 at 5000 mA g−1 (58.8 % capacitance retention), and meanwhile showed a remarkable cycling stability with a high capacity retention of 63 % (333 mAh g−1) after 850 cycles at 5000 mA g−1. Therefore, the HPC/SnOx@NC composite has the potential to be a new generation of LIBs anode.

Synthesis and Characterization of Zinc/Iron Composite Oxide Heterojunction Porous Anode Materials for High-Performance Lithium-Ion Batteries.

Environmental pollution caused by the use of fossil fuels is becoming increasingly serious, necessitating the adoption of clean energy solutions. Lithium-ion batteries (LIBs) have attracted great attention due to their high energy density and currently occupy a dominant commercial position. Metal oxide materials have emerged as promising anode materials for the next generation of LIBs, thanks to their high theoretical capacity. However, the practical application of these materials is hindered by their substantial volume expansion during lithium storage and poor electrical conductivity. In this work, a zinc/iron bimetallic hybrid oxide composite, ZnO/ZnFe2O4/NC, is prepared using ZIF-8 as a precursor (ZIF-8, one of the metal organic frameworks). The N-doped porous carbon composite improves the volume change and optimizes the lithium-ion and electron transport. Meanwhile, the ZnFe2O4 and ZnO synergistically enhance the electrochemical activity of the anode through the built-in heterojunction to promote the reaction kinetics at the interface. As a result, the material delivers an excellent cycling performance of 604.7 mAh g-1 even after 300 cycles of 1000 mA g-1. This study may provide a rational design for the heterostructure and doping engineering of anodes for high-performance lithium-ion batteries.

Hierarchical porous LiVO3/N-doped carbon hollow microspheres as a high-performance anode for lithium-ion batteries

LiVO3 has been considered as a promising anode material for lithium-ion batteries (LIBs) due to its high theoretical capacity. However, the rate capability and cycling stability of LiVO3 are limited by its poor electronic conductivity and low ion diffusion efficiency. In this work, hierarchical porous LiVO3/N-doped carbon hollow microspheres (LiVO3/NC HSs) are designed and synthesized via a simple spray drying method. As an anode material for LIBs, LiVO3/NC HSs show high reversible capacity (557.6 mAh g−1 at 0.5 A g−1) and excellent rate capability (411.5 mAh g−1 at 2.0 A g−1). Even at a high current density of 10.0 A g−1, a capacity retention of 77.0 % can be achieved over 4000 cycles. Such outstanding performance can be attributed to the unique structure, in which LiVO3 particles are in-situ encapsulated in the N-doped carbon network to enhance the electronic conductivity, and the porous and hollow structure enable rapid ion transport and accommodate large volume changes. This work provides novel insights into the design of vanadium-based materials for LIBs.

Trimetallic sulfides coated with N-doped carbon nanorods as superior anode for lithium-ion batteries

Metal sulfides have been considered promising anode materials for lithium-ion batteries (LIBs), due to their high capacity. However, the poor cycle stability induced by the sluggish kinetics and poor structural stability hampers their practical application in LIBs. In this work, MoS2/MnS/SnS trimetallic sulfides heterostructure coated with N-doped carbon nanorods (MMSS@NC) is designed through a simple method involving co-precipitation, metal chelate-assisted reaction, and in-situ sulfurization method. In such designed MMSS@NC, a synergetic effect of heterojunctions and carbon layer is simultaneously constructed, which can significantly improve ionic and electronic diffusion kinetics, as well as maintain the structural stability of MMSS@NC during the repeated lithiation/delithiation process. When applied as anode materials for LIBs, the MMSS@NC composite shows superior long-term cycle performance (1145.0 mAh/g after 1100 cycles at 1.0 A/g), as well as excellent rate performance (565.3 mAh/g at 5.0 A/g). This work provides a unique strategy for the construction of multiple metal sulfide anodes for high-performance LIBs.

Lamellar multi-arch microstructure of Co3O4/N-CNTs-CNF composites as anodes for high-performance flexible lithium-ion batteries

Co3O4 is considered as one of the most promising candidates in lithium-ion batteries (LIBs) anodes due to its low-cost, abundant availability, and high theoretical capacity. However, problems of heavy aggregation, and volume change of Co3O4 hinder its practical applicability. Based on above challenges, we successfully designed and prepared an electrode by adding carbon nanotubes (CNTs) and carbon nanofiber (CNF) via directional freeze-drying. The as-prepared Co3O4/N-CNTs-CNF anode exhibits three-dimensional (3D) network structure to alleviate the volume expansion of Co3O4 and short the electron/ion transport paths. CNTs form a continuous conductive network that provides electron migration paths and prevents agglomeration of Co3O4, while CNF enhances the mechanical strength granting better flexibility. Density functional theory (DFT) calculations reveal that the N-CNTs/Co3O4 interface resulted in an electric field of the heterointerface, which facilitated charge transport. Moreover, the heterointerface possesses good electronic conductivity since more electronic states across the Fermi level. Based on these advantages, Co3O4/N-CNTs-CNF anode demonstrates an initial discharge capacity of 1176 mAh g−1 at a current density of 0.2C, high discharge specific capacity of 545 mAh g−1 at a current density of 5C, only 17.5% capacity loss over 824 cycles at 5C rate. Owing to its good electrochemical performance and flexibility, such design has great potential for applications of portable electronics.

Cation-deficient perovskite Li0.35Nd0.55TiO3 as a high-performance anode for lithium-ion batteries

Due to the advantages in rate capability, cycling performance, and structural stability, oxide perovskites have received increasing attention in the field of fast-charging lithium-ion batteries (LIBs). Here, cation-deficient perovskite Li0.35Nd0.55TiO3 (LNTO) is synthesized and reported as a novel high-performance anode material without further modification. With an average operating potential of 0.73 V vs. Li+/Li, the anode possesses a reversible specific capacity of 202 mAh g−1 at 0.1 C (1 C = 200 mA g−1). Owing to the intrinsically fast Li+ migration channels and three-dimensional skeleton structure, LNTO exhibits excellent rate performance (58 % capacity retention at 40 C) as well as impressive cycling stability (93.5 % capacity retention after 1600 cycles at 10 C). Structural evolution characterization demonstrates a simple solid-solution reaction with the volume change of only 5.51 %. The LiFePO4//LNTO full cell displays outstanding cycling stability (82.8 % capacity retention after 1000 cycles at 5 C) in practical application. Relating the A-site structure to the electrochemical performance, we further provide some insights for the rational design of next-generation fast-charging electrode materials.

Scalable synthesis of N-doped Si/G@voids@C with porous structures for high-performance anode of lithium-ion batteries

Scalable synthesis of N-doped Si/G@voids@C with porous structures for high-performance anode of lithium-ion batteries

Fabrication of SnO2 micron-rods embedding in 3D composite of graphene oxide@MWNTs as high-performance anode for lithium-ion batteries

Tin dioxide-based anode materials have attracted extensive attention in lithium-ion batteries due to their high specific capacity. However, the low intrinsic conductivity and volume expansion of commercial SnO2, as well as the aggregation due to snation result in electrodes that are highly susceptible to crush during the cycling process. Here, SnO2@GO@MWNTs complex consisting of rod-like SnO2 with micron-size uniformly embedded in the multi-walled carbon nanotubes (MWNTs) and multilayer graphene oxide (GO) was constructed via a simple ultrasonic mixing method, and was employed as the anode materials of lithium-ion batteries. This composite electrode showed excellent cycling performance, exhibiting a high reversible capacity of 1242.6 mAh·g−1 after 280 cycles (at 200 mA·g−1), and excellent rate performance at current densities of 1000 mA·g−1 and 2000 mA·g−1, with high specific capacity of 770.5 mAh·g−1 and 640.1 mAh·g−1, respectively. The excellent electrochemical performance was attributed to the fact that the framework structure formed by GO and MWNTs effectively mitigates the volume expansion of rod-shaped SnO2 while improving its electrical conductivity, and the micron-sized rods shape alleviates the aggregation of particles due to the partial tinisation of SnO2.

Hybrid crosslinking for in-situ encapsulation of three-dimensional porous SiOx@rGO as high-performance anodes in lithium-ion batteries

Silicon suboxide (SiOx) anodes have garnered significant attention from both academia and industry due to their superior theoretical capacity compared to graphite, as well as their improved capacity retention in comparison to pure silicon. Nevertheless, SiOx electrodes still confront the challenge of substantial volume expansion (>160 %) during the alloying process, resulting in electrode structural damage or even fragmentation and severely impacting cycling performance. Here, a three-dimensional (3D) conductive network was constructed by ethylenediamine (EDA) cross-linking reduced graphene oxide (rGO), which was encapsulated on the surface of SiOx spheres generated in situ via a magnesium thermal reduction reaction. Accordingly, the SiOx@rGO-EDA anode was prepared successfully with high reversible capacity (892 mAh g−1 after 100 cycles at 1 A g−1) and fascinating rate performance (447 mAh g−1 at 4 A g−1). In full cell, the SiOx@rGO-EDA anode also exhibits outstanding cycling stability (154 mAh g−1 after 100 cycles at 0.1C) and rate capability. The scanning electron microscopy (SEM) images captured from a top-view perspective indicate that the surface of SiOx@rGO-EDA electrode is smooth and dense without any noticeable cracks, and it maintains its structural integrity throughout the cycling process. The cross-sectional thickness of the electrode remains essentially the same. These results illustrate the superior structural stability of the EDA cross-linked graphene conductive network cladding structure, enabling it to adapt to dynamic changes and ensure efficient transport of lithium ions and electrons. The facile and versatile synthesis method of SiOx@rGO-EDA structures by incorporating cross-linking agents provides inspiration for the design of next-generation high-performance anodes.

Facile construction of ZnWO4/ZnO porous nanoplates on reduced graphene oxide for superior lithium storage

Zinc tungstate (ZnWO4) shows great promise as an anode material for lithium-ion batteries (LIBs) owing to its reversible multi-electron redox reactions and high theoretical capacity. Nevertheless, the low conductivity and big strain during cycling can lead to the inferior electrochemical properties of the ZnWO4 anode, hindering its practical application. Herein, we report a novel composite with ZnWO4/ZnO porous nanoplates in-situ constructed on reduced graphene oxide (rGO) by a metal–organic framework template strategy. The nanoplates with good porosity are composed of nanoparticles and nanorods, providing a short Li+-diffusion distance and plentiful Li+ storage active sites. The introduction of rGO can accelerate charge transfer and reinforce structural stability. As a result of these advantages, the ZnWO4/ZnO/rGO composite as LIBs anode delivers a high reversible capacity of 811 mAh g after 100 cycles at 200 mA g−1, excellent rate capability (437 mAh g at 5000 mA g−1), and good long cycling stability (485 mAh g after 500 cycles at 2000 mA g−1). Notably, the rate capability of the composite far precedes the previously reported ZnWO4-based anodes. This work provides an efficient approach for designing and fabricating advanced metal tungstate-based anodes for high-performance LIBs.

Phosphosilicate glass anode for fast charging lithium-ion batteries

We prepare xMoO3-(55-x)SiO2-45P2O5 glass anodes for lithium-ion batteries (LIBs) using melt-quenching method and investigate their physical, thermal, and electrochemical performances. The results show that there exists a critical MoO3 content of 40 mol%, i.e., the 40MSP glass, which gives LIBs the highest fast-charging capacity of 342 mA h g−1 and a high-capacity retention of 99.2 % at 1000 mA g−1 after 1000 cycles. Additionally, 40MSP glass exhibits the highest electric conductivity, the most dramatic changes in molar volume, network structure and Tg among the studied glasses. This work is helpful to develop largescale-preparation and high-performance phosphosilicate glass anodes for LIBs.

A preparation strategy for highly reversible conversion reaction Tin dioxide/ Carbon anode: Simple, ultrafast and scalable

Combining nanoscale engineering and physical confinement approach to prevent aggregation is a reliable strategy to achieve fully reversible conversion reaction SnO2-based anode. However, the synthesis of such nanostructures relies on complex self-sacrificing template preparation and time-consuming thermal treatment processes, which limit the practical application of high-performance SnO2 anodes for lithium-ion batteries. Herein, we present a simple strategy for the in situ preparation of SnO2 quantum dots embedded in carbon martix using an inherently advantageous MOF template and ultrafast microwave-assisted treatment in a few seconds. (denoted as SnO2 QDs@C). The dispersed SnO2 quantum dots with precise size control (≈5 nm) in the nanostructure shorten the lithium ion transport distance and enhance the reaction kinetics. Meanwhile, the carbon matrix promotes electron transport and suppresses Sn coarsening, thus achieving a highly reversible conversion reaction. Consequently, the SnO2 QDs@C anode achieves a reversible capacity of 1337 mAh g-1 after 200 cycles at 0.2 A g-1 with a capacity retention rate of more than 80%. This preparation method can be extended to prepare other metal oxide quantum dots/ Carbon composites and is expected to be applied in a wide range of fields.

High-Performance Silicon-Rich Microparticle Anodes for Lithium-Ion Batteries Enabled by Internal Stress Mitigation

HighlightsThe Sn and Sb incorporation boosts the electronic conductivity and lithium diffusivity of Si anodes, thereby reducing the stress due to lithium concentration gradient.The lithiation of modified electrode mimics isotropic solid solution reaction, rather than the original anisotropic two-phase reaction of Si, effectively weakening the stress concentration.The silicon-rich particles exhibit a capacity of over 1.9 Ah g−1 after 100 cycles at 0.1 A g−1 and maintain the excellent cyclic stability at 3 A g−1.

SiOx coated graphite with inorganic aqueous binders as high-performance anode for lithium-ion batteries

Inorganic aqueous binders (IAB) are an emerging class of aqueous binders. They offer exceptional physicochemical properties like intrinsic ionic conductivity, high thermal stability (>1000 °C), and environmental benignity making them attractive. In a previous study, we found that graphite anode shows improved electrochemical performance with these binders as compared to conventional PVDF binder for lithium-ion batteries (LIB). However, the cyclic performance of graphite-IAB at a higher rate (e.g., 1C) showed a declining trend. We attributed it to the poor binding strength between graphite and IAB due to insufficient functional groups in graphite. Therefore, in this report SiOx-based surface coatings of graphite are employed to improve its rate capability with silicate-based IAB by providing functional silicon oxide polymorphs on the coated graphite as an intermediate layer. The nature and structural arrangement of these coatings are investigated by tip-enhanced Raman spectroscopy (TERS), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). Optimized SiOx-coated graphite (GS) with sodium metasilicate binder leads to excellent cyclic stability with a capacity retention of >90 % at 20C for >4000 cycles. A high specific capacity of >315 mAhg−1 at 2C, stable for over 1000 cycles, is achieved for GS with IAB. The improved performance of the coated graphite is attributed to ameliorated binding with IAB as well as stable solid electrolyte interphase. We propose inorganic aqueous binders in combination with SiOx-coated graphite as an approach to realize a stable anode for LIB.

MOF-SnO2 nanoparticles composited with biomass-derived carbon used as high-performance anodes for lithium-ion batteries

SnO2 has a high specific capacity, low price, and a wide range of sources, but the anode material made from SnO2 is extremely unstable due to volume expansion. In this work, SnO2 nanoparticles were prepared using Sn-MOF as the precursor and compounded with sunflower seed shell porous carbon (SSSC) in a solvothermal manner to obtain a high-performance lithium-ion battery anode. The size of SnO2 nanoparticles prepared using Sn-MOF as the precursor is uniform, only 10–20 nm, which can fully alleviate the volume expansion of SnO2. On this basis, MOF-SnO2 is anchored onto the porous carbon of the sunflower seed shell, which can provide more lithium insertion sites and further inhibit the volume expansion of SnO2. The composite anode in this article has a stable specific capacity of 1050.8 mAh g−1 after 100 cycles at a magnification of 0.2C and a stable specific capacity of 512.9 mAh g−1 after 100 cycles at a magnification of 2C.

Heterointerface Engineered Core-Shell Fe2O3@TiO2 for High-Performance Lithium-Ion Storage.

The rational design of the heterogeneous interfaces enables precise adjustment of the electronic structure and optimization of the kinetics for electron/ion migration in energy storage materials. In this work, the built-in electric field is introduced to the iron-based anode material (Fe2O3@TiO2) through the well-designed heterostructure. This model serves as an ideal platform for comprehending the atomic-level optimization of electron transfer in advanced lithium-ion batteries (LIBs). As a result, the core-shell Fe2O3@TiO2 delivers a remarkable discharge capacity of 1342 mAh g-1 and an extraordinary capacity retention of 82.7% at 0.1 A g-1 after 300 cycles. Fe2O3@TiO2 shows an excellent rate performance from 0.1 A g-1 to 4.0 A g-1. Further, the discharge capacity of Fe2O3@TiO2 reached 736 mAh g-1 at 1.0 A g-1 after 2000 cycles, and the corresponding capacity retention is 83.62%. The heterostructure forms a conventional p-n junction, successfully constructing the built-in electric field and lithium-ion reservoir. The kinetic analysis demonstrates that Fe2O3@TiO2 displays high pseudocapacitance behavior (77.8%) and fast lithium-ion reaction kinetics. The capability of heterointerface engineering to optimize electrochemical reaction kinetics offers novel insights for constructing high-performance iron-based anodes for LIBs.