Lithium-ion Diffusion Kinetics Research Articles

Regulating electronic structure of anionic oxygen by Ti4+ doping to stabilize layered Li-rich oxide cathodes for Li-ion batteries

Abstract Layered Li-rich oxide cathodes enable to activate lattice oxygen anions redox in the charge compensation process and provide superior high specific capacity over 250 mAh/g due to their unique configuration, and thus attracting great attentions as promising cathode candidates for Li-ion batteries. However, how to better stabilize the bulk lattice oxygen framework and surface structure, and slow down the release of oxygen, is still major bottleneck to develop high performance Li-rich materials. Transition metal ions with outer d0 electronic configuration have distortable configuration, which can accommodate the local structure and chemical environment of the material, and then improve structural stability. Herein this work, the d0 transition metal Ti4+ is used as doping element to improve the chemical and structural stability, capacity retention and lithium ion diffusion kinetics of Li-rich material. The role of Ti in the material modification is revealed through synchrotron-based soft X-ray absorption spectroscopy, XRD, XPS and electrochemical tests. The improvement in structural stability can be attributed to that Ti doping can adjust the hybridization of O2p and TM3d to regulate the local electronic structure of both bulk lattice oxygen and surface oxygen vacancies. It is hoped that this work should shed light on the development of high-performance cathode materials for Li-ion Batteries.

One stone, three birds: Cu2+-substituted chloride electrolyte for high-performance all-solid-state lithium batteries

Emerging solid electrolytes, represented by Li2ZrCl6 (LZC), hold great potential due to their lower costs and superior electrochemical stability compared to sulfide SEs (e.g. Li5.4PS4.4Cl1.6). However, challenges such as relatively low ionic conductivity and instability with lithium hinder its widespread application. This work develops a cost-effective strategy by substituting Cu2+ for Zr4+ in LZC electrolyte. The evolution of electrolyte structure at varying substitution levels is comprehensively investigated by synchrotron X-ray diffraction and Raman spectroscopy. The optimized Cu2+-substituted LZC achieves a notable ionic conductivity of 0.75 mS cm−1 due to a reduced energy barrier for Li+ migration confirmed by first-principles calculations. Symmetric lithium cells with the Cu2+-substituted LZC exhibit enhanced inhibition to lithium dendrites than those with Li5.4PS4.4Cl1.6. X-ray photoelectron spectroscopy unveils the key role of Cu2+ reduction in the inhibition of the lithium dendrite, enabling the cell to stably cycle at 0.5 mA cm−2. Moreover, the Cu2+-substituted LZC exhibits improved electrochemical stability, marked by small anodic current exceeding 4 V, reduced polarization, and rapid lithium-ion diffusion kinetics. All-solid-state batteries fabricated with the Cu2+-substituted LZC and Li/LiNi0.8Mn0.1Co0.1O2 electrodes present a high reversible capacity of 139.2 mAh g−1 with retention rate of 96.9 % after 200 cycles at 0.5 C.

Damage-Tolerant and Self-Repairing Web-Like Borate Type Binder Enable Stable Operation of Efficient Si-Based Anodes.

Novel binder designs are shown to be fruitful in improving the electrochemical performance of silicon (Si)-based anodes. However, issues with mechanical damage from dramatic volume change and poor lithium-ion (Li+) diffusion kinetics in Si-based materials still need to be addressed. Herein, an aqueous self-repairing borate-type binder (SBG) with a web-like architecture and high ionic conductivity is designed for Si and SiO electrodes. The 3D web-like architecture of the SBG binder enables uniform stress distribution, while its self-repairing ability promotes effective stress dissipation and mechanical damage repair, thereby enhancing the damage tolerance of the electrode. The tetracoordinate boron ions ( ) in the SBG binder boosts the Li transportation kinetics of Si-based electrodes. Based on dynamic covalent and ionic conductive boronic ester bonds, the diverse requirements of the binder, including uniform stress distribution, self-repairing ability, and high ionic conductivity, can be met by simple components. Consequently, the proposed straightforward multifunction design strategy for binders based on dynamic boron chemistry provides valuable insights into fabricating high-performance Si-based anodes.

Constructing lithium-ion fast pathways via ZnO surface modification to enhance rate capability of graphite anode materials

Graphite materials have attracted widespread attention and application as anodes in lithium-ion batteries due to their abundant raw materials and environmental friendliness. However, poor rate performance is one of the most challenging issues for graphite anodes. In this work, a novel zinc oxide-graphite composite material has been fabricated, which effectively reduces the diffusion resistance of lithium ions during the charge-discharge process. Based on the analysis of the DFT calculations, the introduction of zinc oxide would be an effective way to improve the rate properties of graphite anode materials, owing to the higher lithium-ion diffusion kinetics. The concentration of zinc oxide has been optimized for the electrochemical performances of the composite electrode. Particularly, the 1%ZnO-graphite composite electrode demonstrates significant electrochemical performance with a discharge specific capacity of 337.6 mAh g−1 after 300 cycles at 1C (pure graphite is 300.6 mAh g−1) and excellent rate performance with 190 mAh g−1 at 5C (pure graphite is only 66 mAh g−1). These results pave a new direction for preparing the high rate and long cycle graphite anode materials.

High voltage electrochemical performance of single crystal LiNi0.8Co0.1Mn0.1O2 cathode materials with Al-Mg dual doping

Single-crystal materials have high structural stability and low parasitic side reactions for nickel-rich cathodes due to the absence of grain boundaries. However, they suffer challenges such as the complex synthesis route, sluggish lithium-ion diffusion kinetics, and microcracking evolution at high voltage. Bulk co-doping of Al and Mg into the precursors is first employed by a co-precipitation method, and then the Al-Mg dual-doped single-crystal NCM811 cathode is successfully prepared using a straightforward one-step method to reduce production cost. The cycle retention of the corresponding optimized single-crystal material is notably increased by 24.36% compared to the commercial counterpart at 1 C and a high voltage of 4.5 V. Additionally, the discharge capacity at 0.1 C is improved by 4.64% compared to the commercial one with an appropriate annealing temperature and lithium salt ratio. Some advances in the synthesis approach and modification strategy for developing commercial single-crystal material are provided.

Upgrading anode graphite from retired lithium ion batteries via solid-phase exfoliation by mechanochemical strategy

Vast quantities of anode graphite from waste lithium ion batteries (LIBs), as a type of underrated urban mine, has enormous potential to be exploited for resource recovery. Herein, we propose a benign process integrating low-temperature pyrolysis and mechanochemical techniques to upcycle spent graphite (SG) from end-of-life LIBs. Pyrolysis at 500 °C leads to about 82.2 % PVDF dissociation in thermal treated graphite (TG). Solid-phase exfoliation via ball milling assisted by urea successfully produces abundant graphite flakes and a small amount of monolayer graphene nanosheet at the edge of mechanochemically processed graphite (MG). Subsequent rinsing removes the residual LiF salts. High purity and unique edge structural features of the as-prepared MG offer more active sites and storage reservoir for intercalation and de-intercalation of lithium ions, resulting in enhanced lithium-ion diffusion kinetics, excellent reversible specific capacity and desirable rate capability. Inspiringly, MG exhibits a remarkably enhanced initial specific charge capacity of 521.3 mAh g−1 during the first charge–discharge, and only declines from 569.9 mAh g−1 to 538 mAh g−1 with slight attenuation after 50 consecutive cycles at 0.1 A/g, indicating satisfactory cycle stability. Additionally, the purification and reconstruction mechanism for MG have been illustrated in detail. This study offers a green strategy to reconstruct and upgrade anode graphite from LIBs, which can realize sustainable waste management.

Improving the electrochemical performances and structural stability of ultrahigh-Ni cathodes by using multi-element co-doping methods

Multi-element co-doping and its impact on the stability of the ultrahigh-Ni cathodes during extended cell cycling have not yet been fully established. Synergistic mechanisms still need to be thoroughly understood, and there is potential for further enhancing the structural stability and electrochemical performance of layered cathode materials. In this work, an Nb and Mg co-doped ultrahigh-Ni cathodes (LiNi0.92Co0.06Mn0.02O2) is prepared by solid-state synthesis methods. The effect of Nb and Mg dopants on the microstructure and electrochemical properties are systematically investigated. It is found that the Nb dopant can overcome the main shortcomings provided by Mg doping, including increasing the unit cell volume, suppress harmful phase transformation and enhancing lithium-ion diffusion kinetics. The cathode materials with optimized amounts of Nb and Mg dopants are demonstrated with excellent electrochemical performances. They reveal a specific capacity of 191 mAh g−1 at 1C with a good capacity retention of 92.8% after 500 cycles and a rated capacity of 141 mAh g−1 at 10C. It is also found that excessive Nb doping could lead to a decrease in rhombohedral ordering for crystal lattices, resulting in reduced structural stability and cyclability. This work investigates the strategy of Nb and Mg co-doping for enhancing electrochemical performances of ultrahigh-Ni cathodes, and the results obtained from this work can provide insights into improve the cyclability of these materials.

A green aqueous binder to enhance the electrochemical performance of Li-rich disordered rock salt cathode material

Li-rich disordered rock-salt oxides (DRX) are considered an attractive cathode material in the future battery field due to their excellent energy density and specific capacity. Nevertheless, anionic redox provides high capacity while causing O2 over-oxidation to O2, resulting in voltage hysteresis and capacity decay. Herein, the crystal structure of Li1.3Mn0.4Ti0.3O1.7F0.3 (LMTOF) cathode is stabilized by using sodium carboxymethylcellulose (CMC) binders replacing traditional polyvinylidene difluoride (PVDF) binders. The electrochemical impedance spectroscopy (EIS) and galvanostatic intermittent titration technique (GITT) reveal that the CMC-based LMTOF electrode has higher electronic conductivity and lithium-ion diffusion kinetics. Moreover, CMC has been demonstrated to improve the O2– reversibility, reduce the amounts of byproducts from electrolyte decomposition and suppress transition metal dissolution by Na+/Li+ exchange reaction. Furthermore, the CMC-based LMTOF electrode also exhibits less volume change upon lithiation/delithiation processes compared to the PVDF-based electrode, resulting in enhanced structural stability during cycling. Benefiting from these features, the CMC binders can effectively improve the cycling life and rate performance of the LMTOF cathode, and the CMC-based LMTOF electrode shows good capacity retention of 94.5 % after 30 cycles at 20 mA/g and 66.7 % after 100 cycles at 200 mA/g. This finding indicates that CMC as a binder can efficiently stabilize the structure and improve the electrochemical performance of Li-rich disordered rock-salt oxides cathode, making it possible for practical Li-ion battery applications.

Lithium-Ion Batteries Enhancing Cycling Performance of Silicon Graphite Anodes Using Carbon Nanotubes

Silicon graphite anodes have emerged as promising candidates to replace conventional graphite anodes due to their higher theoretical capacity and ability to store more lithium ions. However, the significant volume expansion of silicon during lithiation and delithiation cycles results in severe mechanical degradation and rapid capacity fade, limiting their practical application. Additionally, the realisation of electrodes with high Si content are further limited by poor diffusion kinetics, resulting in an insufficient rate capability performance and lithium trapping.In this study carbon nanotubes (CNTs) are incorporated into the silicon graphite anode matrix as a strategy to mitigate these issues and enhance the cycling performance of LIBs. The CNTs, with their unique mechanical, electrical, and chemical properties, offer numerous benefits, including enhanced structural integrity, improved electrical conductivity, and increased lithium-ion diffusion kinetics. We investigated the effect of different ratios of CNTs on the cycling performance of silicon graphite anodes. The electrochemical performance of the composite electrodes were systematically evaluated using galvanostatic cycling, cyclic voltammetry, and electrochemical impedance spectroscopy. Preliminary results show that the addition of CNTs to silicon graphite anodes significantly improves their cycling stability and rate capability. The composites exhibit reduced capacity fade, improved coulombic efficiency, and enhanced rate performance compared to silicon graphite anodes absent of the CNTs, facilitated by faster lithium-ion diffusion kinetics, leading to improved electrochemical performance.

A Stable Fe3O4-Based Hybrid Anodes for High Performance Li-Ion Batteries

There is an increasing demand for high-performance Li-ion batteries especially due to environmental concerns. To meet the high-performance requirements of the Li-ion batteries, conversion-type anodes stand out with their capacities. The crystal structure of magnetite (Fe3O4) benefits from its empty interstitial sites which hinders volume changes during the insertion and extraction of lithium ions. Combined with its high theoretical lithium storage capacity and abundance, Fe3O4 has great potential as an alternative anode. Yet in its practical use, the material suffers from severe capacity degradation, mainly due to the formation of a passive metallic iron layer on the electrode [1]. Another suggested mechanism responsible for the deterioration of the performance is the formation of electrochemically inactive FeO-based side products upon delithiation process [2].In this study, we utilize reduced graphene oxide (rGO) as a substrate for the ultrafine Fe3O4 nanoparticles to form a two-dimensional hybrid material with improved characteristics. Under a mild hydrothermal condition, nanoparticles were deposited by a simple redox process in an interconnected porous network of graphene. Graphene aids in improving the Fe3O4 performance not only by reducing the charge transfer resistance, buffering the volume change induced stresses and facilitating the ion transport but also by forming an effective interface with the delocalized electrons of Fe3O4 to further result in the increase of battery capacitance by the interfacial conjugation mechanism, as confirmed by in-situ EIS measurements. The Fe3O4 particles have been effectively stabilized on the rGO surface, becoming less prone to agglomeration during cycling. Consequently, the deliverable specific capacity of the hybrid material was gradually improved upon extended cycling, reaching from 1500 mAh/g up to 2200 mAh/g at 0.5 A/g at the end of 100 cycles of operation. The increase of the specific capacity during the extended cycling was attributed to the chemical and structural changes of the electrode material evaluated by TEM and ex-situ EELS measurements. It was confirmed that the particle size is greatly reduced to 1-2 nm scale, improving the lithium-ion diffusion kinetics by the increased surface area and reversibility of the redox reaction upon graphene contribution. Moreover, the aged cells were observed to still deliver around 1100 mAh/g capacity upon more than 250 times cycling at 1 A/g, indicating the great potential of the ultrafine Fe3O4 decorated reduced graphene hybrids as superior performance Li-ion battery anode materials.

Lithium gallium oxide (LiGaO2): High-performance anode material for lithium-ion batteries

The development of novel anodes is an effective method to improve advanced energy storage devices. In this work, a simple and easily scalable strategy is adopted to construct lithium gallium oxide (LiGaO2) via a facile solid-state reaction method. However, there are few reports on LiGaO2 for lithium-ion battery anodes. The well-designed LiGaO2 fabricated in this work is polycrystalline with a regular polygon shape consisting of fine particles. The lithiation strategy increases the electronic conductivity of LiGaO2 without further carbon coating. After 200 cycles at 0.1 A g−1, the LiGaO2 anode displays good reversible capacity. After 1000 cycles at 3.0 A g−1, the capacity retention is 253.3 mA h g−1. Electrochemical results show that this lithiation strategy can accelerate lithium-ion diffusion and charge transfer kinetics of the LiGaO2 anode and alleviate the pulverization of the electrochemical reaction. The ex situ XRD result confirms the good structural stability of the LiGaO2 anode. This study demonstrates the necessity of developing new anode materials with good cycling stability via this lithiation strategy.

Synergistic effect of B[sbnd]Nb co-modified to achieve crystal structure and interface tuning for Ni-rich cathode

Nickel-rich cathode materials play a pivotal role in the functioning of lithium-ion batteries, but their crystal structure defects and surface side reactions significantly affect battery performance. This has slowed down the commercialization process of nickel-rich cathodes. To remedy these problems, a new strategy utilizing B and Nb for crystal structure and interface control of LiNi0.8Co0.1Mn0.1O2 (NCM811) is proposed in this study. The BNb modified cathode exhibits strong radial orientation and exposes a large number of active (003) lattice plane on the particle surface. This structural control reduces micro-cracks and accelerates lithium-ion diffusion kinetics. Additionally, the LiNbO3 coating effectively avoids immediate contact between secondary particles and the electrolyte, greatly alleviating side reactions. Consequently, the optimal cathode B-NCM@LNO5 modified cathode maintains a capacity retention of 86.71% after 200 cycles at 1 C, outperforming the original material (76.11% retention). Meanwhile, it demonstrates attractive rate capability of 158.4 mAhg−1 under 5 C. This research provides valuable insights for addressing anisotropic strain and interface compatibility issues in nickel-rich cathodes.

Design of phosphorus-doped porous hard carbon/Si anode with enhanced Li-ion kinetics for high-energy and high-power Li-ion batteries

With the rapid progress of portable electronics and electric vehicles, high-energy lithium-ion batteries (LIBs) with fast-charging technology are urgently required. Silicon (Si) is considered as the most promising anode candidate for high-energy LIBs but challenging to large-scale commercialization due to its huge volume change and poor conductivity. To develop high-capacity Si-based anode materials with enhanced lithium-ion diffusion and fast reaction kinetics, we design a novel high-Si-content Si/hard carbon composite via scalable methods. The combination between phosphorus-doped hard carbon with porous structure and uniformly distributed Si nanolayers effectively improve lithium-ion kinetics and mitigate the volume change of Si. As a result, the architecture delivers a reversible capacity of 1124 mAh/g at 0.1C and superior cycling stability with an 87.4% capacity retention after 200 cycles at 1C. The 1.5 A h pouch-type full-cell tests further demonstrate good cycling stability and high rate performance at 4C under an electrode density of 1.6 g cm−3 and areal capacity loading of 3.53 mAh cm−2. This work paves a new way for the rational design of Si-based anode materials for high-energy and high-power LIBs.

Preparation of low cobalt-doped LiNiO2 materials by the spray pyrolysis method

LiNiO2 (LNO) is recognized as the most promising cathode material for next-generation lithium-ion batteries owing to its highest energy density and economic benefit in the layered oxide cathode materials systems. However, severe cation disordering, multiple phase transformations and poor lithium-ion diffusion kinetics, which result in rapid degradation of cycling stabilities and rate properties, hinder its further practical applications. Cobalt doping is an effective strategy to address such issues, but the influences of cobalt on LNO materials have not been figured out completely yet. Hence, a systematical investigation of cobalt doping for LiNiO2 cathode materials prepared by spray pyrolysis is conducted. The addition of cobalt enhances the stabilities of layered structures and suppresses the cation disordering effectively. The multiple-phase transformations during cycling are also alleviated significantly. Furthermore, cobalt doping can decrease charge transfer resistances and improve lithium-ion diffusion kinetics, especially at high de-lithiation states. As a result, the electrochemical performances are improved comprehensively after cobalt doping. The LNO with optimal doping amount exhibits an improved capacity retention of 78.0% after 100 cycles as compared with 64.9% for pristine LNO, and an outstanding rate performance of 167.2 ​mA ​h ​g−1 with the current density of 5 ​C (1 ​C ​= ​200 ​mA ​g−1).

Construction of the 12-Phosphomolybdate-based Coordination Polymer @ Crumpled Graphene Balls Composite as Anode for Lithium Batteries.

To address the poor electronic conductivity and conventionally lose easily of polyoxometalates (POMs), and considering the high electrical conductivity and configuration advantages of crumpled graphene balls (CGBs), herein, a series of POM-based coordination polymers [Cu(pyttz)2]PMo12@CGB (n, n = 1, 2, 3) were successfully synthesized, and electrochemical lithium storage performance and lithium ion diffusion kinetics were comprehensively investigated. Galvanostatic intermittent titration technique (GITT) and electrochemical impedance spectroscopy (EIS) study-confirm that [Cu(pyttz)2]PMo12@CGB (n, n = 1, 2, 3) integrates the advantage of high electronic conductivity of CGB and excellent Li+ migration kinetics of POMs, which greatly ameliorates the electrochemical performances of POMs, among [Cu(pyttz)2]PMo12@CGB (2) exhibits an excellent reversible specific capacity of around 941.4 mA h g-1 at 0.1 A g-1 after 150 cycles and admirable rate performance. This work will promote the development of POMCP anodes, thus fulfilling their potential in high-performance LIBs.

Vacuum filtration-casted hierarchical carbon skeleton/TiO2 thick electrodes for lithium-ion batteries with high areal capacity

Enhancing the areal capacity of lithium-ion batteries (LIBs) via designing of thick electrodes attracts significant interest. To promote this issue, carbon microfiber (CMFs) and carbon nanotubes (CNTs) are introduced as most electrode skeletons to improve the kinetics of the thick electrodes. Herein, self-supportive integrated thick electrodes with dual hierarchical carbon skeleton of CMFs and CNTs, and TiO2 are synthesized via vacuum filtration-casting technique. By tuning the ratio of both CMF and CNT, the optimized electrode achieves relatively high reversible areal capacity of 5.32 mAh cm−2@0.0125 A g−1, attractive rate performance of 0.91 mAh cm−2@0.50 A g−1 and impressive cyclic stability areal capacity of 2.75 mAh cm−2@0.10 A g−1 up to 150 cycles as anode material for LIBs. The enhanced performance can be attributed to the interconnected hierarchical carbon architecture and synergistic effect between the individual materials that facilitates better electrical conductivity for the rapid lithium-ion diffusion kinetics. Furthermore, in situ Raman analysis provides clear evidence for the rapid electronic/ionic transport kinetics in the proposed integrated architecture electrode. This work provides more options for the synthesis of thick electrodes for high performance and high areal capacity LIBs.

Tuning nickel cobalt sulfides embedded in hierarchical porous carbon nanosheets/carbon nanotubes interpenetrating frameworks by in situ bimetallic MOF-derived engineering towards exceptional lithium storage

A Ni/Co-MOF-engaged bimetallic nickel cobalt sulfide nanoparticles encapsulating into a 3D interpenetrating hierarchical porous ultrathin carbon nanosheets/carbon nanotubes framework (NiCo2S4 @HPCS/CNTs) have been designed and fabricated via carbonization under the reducing atmosphere and further sulfurization processes. The in situ development of extruded CNTs from organic ligands in MOF templates is autocatalyzed by the metal nanoparticles created during the reduction process. Intriguingly, MOFs serve as periodically atom-dispersed self-sacrificial templates for the in situ formation of hierarchical porous carbon-encapsulated micro/nano heterostructure materials. NiCo2S4 nanocrystals are uniformly dispersed into the 1D CNTs/2D carbon nanosheets/3D carbon spheres conductive networks in this special compositional and hierarchical structure, effectively inhibiting volume expansion, enhancing the electronic conductivity, and further enabling ultrafast lithium ion diffusion kinetics. When used as anode materials of lithium-ion battery (LIB), the NiCo2S4 @HPCS/CNTs electrode delivers outstanding cycling stability with capacity retention of 782.4 mAh g−1 after 800 cycles at 1 A g−1 and excellent rate capability of 584.9 mAh g−1 at a high current density of 4 A g−1. This study provides a novel approach for preparing multi-metallic sulfide generated from MOF precursors with surprisingly heterostructures as the advanced anode materials for LIBs.

Synergistic effect on the improved lithium ion storage performance in the porous Fe2O3@Fe3C@C composite

The porous Fe2O3@Fe3C@C composite was synthesized by a simple two-step thermal treatment and its structure, morphology, lithium ion storage performance and diffusion kinetics were discussed. Benefitting from the high theoretical capacity of Fe2O3 and fast kinetics of Fe3C, the Fe2O3@Fe3C@C composite exhibits a stable cycling capacity of 800.3 mAh g−1 after 100 cycles at 0.1 A g−1 with superior rate capability. The CV and in-situ EIS analysis results reveal that the Fe2O3@Fe3C@C composite has reversible redox reaction, stable solid electrolyte interphase films and low charge transfer resistance during the discharging and charging process. In addition, the lithium ion diffusion coefficients of the Fe2O3@Fe3C@C composite at different voltage states are investigated by GITT measurement. This work can provide an effective strategy for synthesis of metal oxide@metal carbide composite for lithium-ion batteries.

Core-shell structure of polyacrylate-based binder enhancing the wet-adhesion strength and the kinetics of lithium-ion diffusion

Despite constituting only a small fraction of the mass of an electrode, the binder is one of the key components ensuring the long-term durability of lithium-ion batteries (LIBs). The need for higher energy density and superior power characteristics necessitates the enhancement of the adhesion properties of the binder to reduce the binder contents of electrodes. In this study, we synthesized a core-shell structured poly(acrylonitrile-co‑butyl acrylate) binder that exhibits higher adhesion strength, lower kinetic resistance, and higher electrode and cell lithium-ion diffusion coefficients than those of styrene-butadiene rubber, which is widely used in commercial LIBs. The polystyrene (PS) constituting the core enhanced the electrical conductivity, while the lone pairs of electrons of poly(acrylonitrile-co‑butyl acrylate) expedited the lithium ion movement, thereby enhancing the kinetics of LIBs. The adhesion properties were enhanced in the presence of the carbonate-based liquid electrolyte owing to the carboxyl groups introduced by itaconic acid on the shells.

Black phosphorus stabilized by titanium disulfide and graphite via chemical bonds for high-performance lithium storage

Black phosphorus (BP) anode has received extensive attentions for lithium-ion batteries (LIBs) due to its ultrahigh theoretical specific capacity (2596 mAh g−1) and superior electronic conductivity (≈102 S m−1). However, the enormous volume variations during lithiation/delitiation processes greatly limit its applications. Herein, a new BP-titanium disulfide-graphite (BP-TiS2-G) nanocomposite composed of BP, titanium disulfide and graphite has been prepared by a facile and scalable high-energy ball milling method. The experimental data proves that PC and PS bonds have been successfully introduced at the interface, which can effectively maintain the structural integrity of the BP-TiS2-G electrode when evaluated as an anode material for LIBs. In addition, lithium-ion diffusion kinetics have been demonstrated to be enhanced from the synergistic effect of PC and PS bonds. As a result, the BP-TiS2-G anode shows outstanding cycling stability (906.2 mAh g−1 after 1300 cycles at 1.0 A g−1) and superior rate performance (313.8 mAh g−1 at 10.0 A g−1). Our work shows the synergistic effects of different chemical bonds to stabilize BP can be a potential strategy for the development of high-performance alloy-type anodes for rechargeable batteries.