High-performance Lithium-ion Batteries Research Articles

Melamine Polymerization Promotes Compact Phosphorus/Carbon Composite for High-Performance and Safe Lithium Storage.

Phosphorus is regarded as a promising material for high-performance lithium-ion batteries (LIBs) due to its high theoretical capacity, appropriate lithiation potential, and low lithium-ion diffusion barrier. Phosphorus/carbon composites (PC) are engineered to serve as high-capacity high-rate anodes; the interaction between phosphorus and carbon, long-term capacity retention, and safety problems are important issues that must be well addressed simultaneously. Herein, an in situ polymerization approach to fabricate a poly-melamine-hybridized (pMA) phosphorus/carbon composite (pMA-PC) is employed. The pMA hybridization enhances the density and electrical conductivity of the PC, improves the structural integrity, and facilitates stable electron transfer within the pMA-PC composite. Moreover, the pMA-PC composite exhibits efficient adsorption of lithium polysulfides, enabling stable transport of Li+ ions. Therefore, the pMA-PC anode demonstrates a high specific charging capacity of 1,381mAhg-1 at 10Ag-1, and a great capacity retention of 86.7% at 1Ag-1 over 500 cycles. The synergistic effect of phosphorus and nitrogen further confers excellent flame retardant properties to the pMA-PC anode, including self-extinguishing in 2.5s, and a much lower combustion temperature than PC. The enhanced capacity and safety performance of pMA-PC show potential in future high-capacity and high-rate LIBs.

Interface chemical reconstruction with residual lithium compounds on nickel-rich cathode by nonstoichiometrical MoO3-x coating enables high stability

The layered lithium nickel-rich cathodes have become one of the most promising candidates for next-generation lithium-ion batteries with high energy density, However, the nickel-rich cathode suffers from a rapid decay of capacity due to their intrinsic instability and undesirably residual lithium compounds originated from LiNiO2 structural changes on the surface, hindering large-scale commercial application. Herein, a continuous and uniform oxygen vacancy enriched-MoO3-x coating was successfully synthesized and reacted residual lithium compounds as a functional layer on the cathode. Such chemically reconstructed coating (Li2MoO4) strategy endows the 1 wt% MoO3-x coated NCA cathode with a fast Li+ ions transport and enhanced structural stability, leading to an outstanding discharge capacity of 214.0 mAh g−1 at 0.1C (1C = 270 mA g−1), a better capacity retention of 80.3 % after 120 cycles at 0.5C, and an excellent high rate capability of 120 mAh g−1 at 5C cycled in voltage range of 2.75 V–4.3 V. This work provides an effective strategy to modulate surface structure towards advanced Ni-rich cathodes for high-performance lithium-ion batteries.

N-doped C encapsulated Li2TiSiO5 nanoparticles for high-rate highly stable lithium storage

Achieving high charging rates (≤ 15 min) in lithium-ion batteries (LIBs) is imperative for their widespread implementation in all-electric vehicles. However, the pursuit of elevated charging rates often leads to compromises in capacity and cycling stability. In this manuscript, we present a groundbreaking approach utilizing a composite material composed of nitrogen-doped carbon-encapsulated Li2TiSiO5 nanoparticles (LTSO@C-N) as the anode material for LIBs, offering rapid and exceptionally stable lithium storage. The encapsulation of Li2TiSiO5 nanoparticles by nitrogen-doped carbon is realized via a facile liquid-phase polymerization and the following pyrolysis route. The uniformly deposited nitrogen-doped carbon layer on the surface of Li2TiSiO5 nanoparticles within LTSO@C-N serves a dual purpose: enhancing the conductive properties of Li2TiSiO5 to ensure efficient charge transfer and Li+ transport, while concurrently inhibiting grain pulverization over extended cycling periods. The deliberate incorporation of nitrogen-doped carbon optimizes Li2TiSiO5 anode electrochemical performance, simultaneously reducing structural degradation during prolonged cycling. This enhances the lithium-ion battery system's long-term stability and reliability. While exhibiting an average operational potential of approximately 0.28 V in comparison to Li+/Li, the LTSO@C-N electrode manifests a commendable specific capacity of 345 mAh g-1 at a current density of 0.1 A g-1. Notably, it attains a robust lithium storage capability even under high-rate conditions, exemplified by a sustained capacity of 205 mAh g-1 over 1000 cycles at 2 A g-1, devoid of any discernible decay. The electrode's impressive electrochemical performance highlights its potential as an advanced anode for high-performance lithium-ion batteries, ensuring stability.

Investigating the expansion behavior of silicon nanoparticles and the effects of electrolyte composition using a graphene liquid cell

Understanding the volume expansion behavior of Si anodes and their interaction with electrolyte environments is crucial for developing high-performance lithium-ion batteries (LIBs). This study utilizes a graphene liquid cell for in situ imaging to systematically investigate the volume expansion and etching behavior of Si anode nanoparticles in different electrolyte environments. Comparative experiments on Si@C core-shell nanoparticles assess their volume expansion dynamics. The findings reveal significant variation in the expansion rate of nano Si depending on the electrolyte environment, with chemical etching observed under specific conditions. Conversely, Si@C core-shell structures show mitigated expansion due to the confinement effect of the carbon matrix. Battery performance experiments validate these results, demonstrating the excellent cycling stability of Si@C anodes. Various coating agents are explored to optimize Si@C structures, with dopamine thin layer coating exhibiting the best cycling stability. This study offers fundamental insights into Si anode expansion, electrolyte effects, and carbon coating impacts, advancing LIB technology.

Effects of transition metal ions migration at the cathode|electrolyte interface on the performance of thin-film Lithium-ion batteries with NCM cathodes

The advent of all-solid-state thin-film lithium-ion batteries (LIBs) has revolutionized the powering of microsystems due to their miniaturization ease and seamless integration capabilities. Despite the pressing demand for LIBs with higher energy density and enhanced safety, the performance of these devices has been consistently hindered by the complex interfacial dynamics at the cathode|electrolyte boundary. This study delves into the nuanced characterization of transition metal (TM) ions at the cathode|electrolyte interface, utilizing LiNi0.5Co0.2Mn0.3O2 (NCM523) thin films as the cathode material for LIBs. We meticulously explored the profound impact of NCM523|LiPON interfacial properties on the LIBs' overall performance, uncovering that the migration of TM ions and the emergence of TM–O spinel phases, induced by targeted annealing treatments of the cathodes, play pivotal roles in dictating the battery's capacity density and cycling stability. Heat treatments at 600 and 800 °C led to the formation of inhomogeneous spinel-phase nanolayers on the surfaces of NCM523 thin films, which hindered Li+ transport and affected the LIBs. In stark contrast, the 700 °C treatment yielded a pristine layered structure with clear boundary against LiPON, culminating in a battery with outstanding capacity density and remarkable cycle stability. Our theoretical calculations have unraveled that the temperature-dependent migration of TM ions is intricately linked to the varying strengths of TM–O bonds and the associated Jahn-Teller effects, providing a novel perspective on the design of high-performance LIBs.

Tailoring the Size of Reduced Graphene Oxide Sheets to Fabricate Silicon Composite Anodes for Lithium-Ion Batteries.

The integration of a silicon (Si) anode into lithium-ion batteries (LIBs) holds great promise for energy storage, but challenges arise from unstable electrochemical reactions and volume changes during cycling. This study investigates the influence of reduced graphene oxide (rGO) size on the performance of rGO-protected Si composite (Si@rGO) anodes. Two sizes of graphene oxide (GO(L) and GO(S)) are used to synthesize Si@rGO composites with a core-shell structure by spray drying and thermal reduction. Electrochemical evaluations show the advantages of the Si@rGO(S) anode with improved cycle life and cycling efficiency over Si@rGO(L) and pure Si. The Si@rGO(S) anode facilitates the formation of a stable LiF-rich solid electrolyte interface (SEI) after cycling, ensuring enhanced capacity retention and swelling control. Rate capability tests also demonstrate the superior high-power performance of Si@rGO(S) with low and stable resistances in Si@rGO(S) over extended cycles. This study provides critical insights into the tailoring of graphene-protected Si composites, highlighting the critical role of rGO size in shaping structural and electrochemical properties. The Si material wrapped by graphene with an optimal lateral size of graphene emerges as a promising candidate for high-performance LIB anodes, thereby advancing electrochemical energy storage technologies.

Design a polymer-based composite electrolyte with high ionic conductivity for high-performance lithium-metal batteries

Constructing a stable and robust solid polymer electrolyte (SPE) is crucial for achieving dendrite-free lithium-metal anodes and high-performance lithium batteries. However, realizing the integrity of solid electrolytes with high ion conductivity during long-life cycling under high current density remains a significant challenge. In this study, we propose a multifunctional SPE with a polyvinylidene fluoride (PVDF)/co-polyphenol coordination polymer (EACo2) hybrid composite to improve the durability of Li metal anode during repeat plating/stripping cycles by using a facile solution-casting method. The PVDF as a substrate with high mechanical strength and improved lithiophilicity exhibits high ionic conduction and excellent dendrite inhibition ability; meanwhile, the EACo2 fillers with a high density of Lewis-acidic sites contribute to the dissociation of lithium salts and decrystallization of the PVDF, resulting in a high Li-ion transference number and ion conductivity (2.66 × 10−3 S cm−1 at 30 ℃). The symmetrical cells with PVDF/EACo2 SPE can stabilize cycling over 1200 hours at a deposition capacity of 0.1 mAh cm−2. Moreover, the assembled full cells Li|LiFePO4 demonstrate long-term stability (1000 cycles at 1 C) with impressive capacity retention of 75 %, offering a promising approach towards high-performance lithium metal batteries.

Copper nitrate enables high-performance Lithium-ion batteries at low temperature

Lithium-ion batteries (LIBs) have dominated the market for electrochemical energy storage owing to their high energy density and extraordinary cycle life. However, the similar potentials of Li⁺ intercalation and Li plating result in severe capacity loss and dendrite growth on graphite anodes under extreme operating conditions, which significantly limits their applications. In this work, under the guidance of density functional theory (DFT) calculations, copper nitrate (Cu(NO3)2), a cheap and functional inorganic additive, was demonstrated a good capability to increase the potential gap by 39 mV at room temperature and as high as 67 mV at -20 °C. Moreover, the rate performance was improved significantly due to the formation of a Li3N-enriched interface. As a result, the LiNi0.8Mn0.1Co0.1O2||graphite pouch cells deliver higher capacity and better cycle stability at low temperature. This technology contributes to facilitating the adjustment of the charge and discharge protocol, allowing LIBs to perform better under extreme conditions.

Facile preparation of surface-modified polypropylene nanofiber separators with enhanced ionic transport and welding performance for lithium-ion batteries

Nanofiber separators are promising for high-performance lithium-ion batteries due to their high porosity and electrolyte uptake. However, most of them have been criticized for the low mechanical strength, particularly polyolefin nanofiber separators, due to the poor welding performance caused by weak interaction among the fibers. The lack of mass-production techniques is another problem for polyolefin nanofiber separators though polyolefin has the competitive cost and stability. In present study, polypropylene nanofiber separators (PPNFS) prepared via nanolayer coextrusion, a new appeared method suitable for large-scale preparation, are surface modified via a simple dip-coating method. The electrostatic self-assembly on the surface of polypropylene nanofibers is achieved. The incorporation of modified polymers significantly enhances the interaction at the nanofiber overlaps, facilitating in-situ welding of nanofibers and resulting in an 800 % enhancement in separator mechanical properties. Polybenzimidazole (PBI) is a strange polymer with both electron-donating and electron-accepting sites. Experimental characterization and simulation calculations confirm that PBI-modified PPNFS exhibit a distinctive enhanced ionic transport and promote the formation of a more homogeneous solid electrolyte interphase (SEI) layer. Furthermore, PBI coated PPNFS (PPNFS@PBI) separators demonstrate exceptional thermal stability, superior electrolyte uptake, and enhanced fire resistance. Finally, the effect of molar concentration and molecular weight of PBI on battery performance is evaluated. 15 % Molar concentration of PBI with 88,000 molecular weight has been shown to maximize battery performance.

Controlled Growth Lateral/Vertical Heterostructure Interface for Lithium Storage.

Artificial heterostructures with structural advancements and customizable electronic interfaces are fundamental for achieving high-performance lithium-ion batteries (LIBs). Here, a design idea for a covalently bonded lateral/vertical black phosphorus (BP)-graphdiyne oxide (GDYO) heterostructure achieved through a facile ball-milling approach, is designed. Lateral heterogeneity is realized by the sp2-hybridized mode P-C bonds, which connect the phosphorus atoms at the edges of BP with the carbon atoms of the terminal acetylene in GDYO. The vertical connection of the heterojunction of BP and GDYO is connected by P-O-C bond. Experimental and theoretical studies demonstrate that BP-GDYO incorporates interfacial and structural engineering features, including built-in electric fields, chemical bond interactions, and maximized nanospace confinement effects. Therefore, BP-GDYO exhibits improved electrochemical kinetics and enhanced structural stability. Moreover, through ex- and in-situ studies, the lithiation mechanism of BP-GDYO, highlighting that the introduction of GDYO inhibits the shuttle/dissolution effect of phosphorus intermediates, hinders volume expansion, provides more reactive sites, and ultimately promotes reversible lithium storage, is clarified. The BP-GDYO anode exhibits lithium storage performance with high-rate capacity and long-cycle stability (602.6 mAh g-1 after 1000 cycles at 2.0 A g-1). The proposed interfacial and structural engineering is universal and represents a conceptual advance in building high-performance LIBs electrode.

A study on molecular weight controlled conducting polymer-based binder for high-performance lithium-ion battery anodes

A study on molecular weight controlled conducting polymer-based binder for high-performance lithium-ion battery anodes

Design Principle and Development Trends of Silicon-Based Anode Binders for Lithium-ion Batteries: A Mini Review

Abstract: Silicon (Si), recognized as a promising alternative material for the anodes of lithium-ion batteries, boasts a high theoretical specific capacity and abundant natural availability. During the preparation of silicon-based anodes, binders play a pivotal role in ensuring the cohesion of silicon particles, conductive agents, and current collectors. The structure and performance of these binders are critical for the mechanical stability, electrical conductivity, and stress dissipation capacity of the anodes. This review initially outlines the structural characteristics of various binders, including linear, branched, and three-dimensional cross-linked types. It then delves into the relationship between the structure and properties of these binders in the context of their application in high-performance lithium-ion batteries, focusing on their mechanical properties, electrical conductivity, and self-healing capabilities. Particular attention is given to the design strategies for binders that facilitate stress dissipation, with an emphasis on integrating multifunctional polymer binders renowned for their superior conductive and self-healing features. Such binders contribute to the formation of a robust three-dimensional network structure via multiple bonding mechanisms, including chemical, non-covalent, and coordination interactions. This configuration significantly enhances the adhesion between silicon particles, thereby facilitating the efficient dissipation of stress, which is a key aspect for ensuring the long-term cycling stability of lithium-ion batteries. Lastly, the paper explores future development directions for silicon anode binders, advocating for a thorough investigation into the synergy of diverse structural and functional combinations, with the aim of advancing the performance and practical application of silicon-based lithium-ion batteries.

Modulation of physical and chemical connections between SiOx and carbon for high-performance lithium-ion batteries

Modulation of physical and chemical connections between SiO_x and carbon for high-performance lithium-ion batteries

4-fluorophenylboronic anhydride as an impurity-scavenging agent and two-sided interface modifier for high-performance lithium ion batteries

In this work, an electrolyte optimization strategy is proposed for simultaneously stabilizing the two-sided interfaces in the LiNi0.5Co0.3Mn0.2O2 (NCM)/Si-C batteries by employing a multifunctional additive, 4-fluorophenylboronic anhydride (TFTB). It is revealed that the TFTB is capable of scavenging the trace amount of moisture and HF acidic species in the electrolyte by strongly coordinating with them, meanwhile, possesses preferential reduction/oxidation sequence in contrast to conventional carbonate solvents. Profited from these synergistic effects from the additive, favorable interface chemistry can be simultaneously built on both Si-C anode and NCM cathode accompanied by greatly suppressed electrolyte degradation, which not only well accommodates the volume change of the Si-C anode during cycling, but also effectively protects the NCM cathode from structural destruction. Consequently, the addition of the TFTB endows the NCM/Si-C full cell with improved reversible capacity and cycle performance.

High-performance lithium batteries achieved by electrospun MXene-Enhanced cation-selective membranes

Conventional separators applied in lithium batteries face limitations like low porosity, poor electrolyte wettability, lower cation selectivity, and thermal instability, which impact battery performance and safety characteristics. Besides the challenge in separator design, transition metal ion migration from positive electrodes during cycling greatly accelerates capacity fading because of unrestricted diffusion of transition metal cation across the separator. This study explores an innovative strategy for the separator design by incorporating MXene (spraying MXene solution on both sides of the separator), a two-dimensional material, into electrospun Polyacrylonitrile/Polyetherimide membranes with the function of cation selection. Li+ can be accelerated, and its transference number increases along with the anion limitation in the MXene layer. Ni, Co, and Mn ion dissolution from the positive electrode is inhibited due to the cation selectivity of the MXene layer. Leveraging electrospinning advantages, the resultant membranes exhibit high porosity, excellent liquid absorption, mechanical strength, and superior thermal properties. Benefiting from MXene's layered structure and excellent adsorption ability, the membrane significantly inhibits the dissolution of transition metal ions while enabling smooth lithium deposition due to its cation selectivity. Eventually, the Li||NMC811 batteries deliver outstanding cyclic performance (91.3 % capacity retention after 200 cycles) and robust lithium dendrite suppression (800 h of stable cycling). Moreover, the MXene-modified membrane demonstrates exceptional electrolyte wettability, significantly improving ionic transference number (0.67) and conductivity (1.6 mS/cm). Modification of membrane surfaces with MXene offers insights into addressing transition metal ion migration from the positive electrode material perspective, providing a promising avenue for high-performance LIBs.

High loading electrode with superior electron/ion transport network for high performance lithium-ion batteries

High loading electrode design is beneficial to increase the energy density of lithium ion batteries. Two obstacles for the high loading electrode application should be removed, including the limitation on ion/electron transport within high loading electrode and the structure stability. Here, the electron conduction on LiNi0.8Co0.1Mn0.1O2 cathodes is enhanced with evenly and tightly Ketjen Black coating via high-speed dry mixing, while carbon nanotube is added to enhance the electron conduction between LiNi0.8Co0.1Mn0.1O2 particles, thus to construct three-dimensional electron migration channel. In addition, the large amount of electrolyte adsorbed by porous Ketjen Black and carbon nanotube enhances the Li+ ion diffusivity in this network. As a result, LiNi0.8Co0.1Mn0.1O2 electrode with only 1 % Ketjen Black and 3 % carbon nanotube can achieve both high electron/Li+ ion diffusivity and high parking density (2.2 g cm−3). A thick electrode with an areal mass loading of 20 mg cm−2 shows a high specific capacity of 111.2 mA h g−1 at 4 C and capacity retention rate of 98.2 % after 100 cycles at 2 C.

Electrospinning carbon-coated hollow aluminum nanobeads fibers for high-performance lithium-ion batteries

Aluminum (Al) anodes remain a significant challenge for industrial applications, especially when incorporated into full cells. In this study, we introduce an innovative design featuring Al hollow nanobeads anchored to carbon fibers (Al HNBs/CF) to address the issue of cracking and pulverization during repeated charge and discharge cycles, thereby enhancing the structural stability of the Al-based anode. The carbon fiber buffer effectively enhances Al utilization and reaction uniformity, resulting in the Al HNBs/CF anode achieving a high specific capacity (∼834 mAh g−1 at 0.2 C) and exceptional electrochemical durability, with only 0.0062 % capacity degradation per cycle over 1000 cycles. Furthermore, when paired with a commercially available LiFePO4 (LFP) cathode, the full cell exhibits a satisfactory energy density surpassing that of most recently reported LFP-based lithium-ion batteries. These results suggest that our design effectively mitigates the challenges associated with Al-based anodes and holds promise for practical applications in portable electronics.

Imidazole-Intercalated Cobalt Hydroxide Enabling the Li+ Desolvation/Diffusion Reaction and Flame Retardant Catalytic Dynamics for Lithium Ion Batteries.

Lithium-ion batteries have found extensive applications due to their high energy density and low self-discharge rates, spanning from compact consumer electronics to large-scale energy storage facilities. Despite their widespread use, challenges such as inherent capacity degradation and the potential for thermal runaway hinder sustainable development. In this study, we introduce a unique approach to synthesize anode materials for lithium-ion batteries, specifically imidazole-intercalated cobalt hydroxide. This innovative material significantly enhances the Li+ desolvation/diffusion reaction and flame-retardant dynamics through complexing and catalytic synergetic effects. The lithium-ion batteries incorporating these materials demonstrate exceptional performance, boasting an impressive capacity retention of 997.91 mAh g-1 after 500 cycles. This achievement can be attributed to the optimization of the solid electrolyte interphase (SEI) interface engineering, effectively mitigating anode degradation and minimizing electrolyte consumption. Experimental and theoretical calculations validate these improvements. Importantly, imidazole intercalated Co(OH)2 (MI-Co(OH)2) exhibits a remarkable catalytic effect on electrolyte carbonization and the conversion of CO to CO2. This dual action suppresses smoke and reduces toxicity significantly. The presented work introduces a novel approach to realizing high-performance and safe lithium-ion batteries, addressing key challenges in the pursuit of sustainable energy solutions.

Engineering a Low-Strain Si@TiSi2@NC Composite for High-Performance Lithium-Ion Batteries.

The huge volume expansion/contraction of silicon (Si) during the lithium (Li) insertion/extraction process, which can lead to cracking and pulverization, poses a substantial impediment to its practical implementation in lithium-ion batteries (LIBs). The development of low-strain Si-based composite materials is imperative to address the challenges associated with Si anodes. In this study, we have engineered a TiSi2 interface on the surface of Si particles via a high-temperature calcination process, followed by the introduction of an outermost carbon (C) shell, leading to the construction of a low-strain and highly stable Si@TiSi2@NC composite. The robust TiSi2 interface not only enhances electrical and ionic transport but also, more critically, significantly mitigates particle cracking by restraining the stress/strain induced by volumetric variations, thus alleviating pulverization during the lithiation/delithiation process. As a result, the as-fabricated Si@TiSi2@NC electrode exhibits a high initial reversible capacity (2172.7 mAh g-1 at 0.2 A g-1), superior rate performance (1198.4 mAh g-1 at 2.0 A g-1), and excellent long-term cycling stability (847.0 mAh g-1 after 1000 cycles at 2.0 A g-1). Upon pairing with LiNi0.6Co0.2Mn0.2O2 (NCM622), the assembled Si@TiSi2@NC||NCM622 pouch-type full cell exhibits exceptional cycling stability, retaining 90.1% of its capacity after 160 cycles at 0.5 C.

Bifunctional effects of nitrogen-doped carbon quantum dots on CoS2/mesoporous carbon composites for high-performance lithium-ion batteries

Cobalt disulfide (CoS2) stands as a promising candidate for anode materials in lithium-ion batteries due to its high theoretical capacity, but it faces challenges associated with the shuttle effect of lithium polysulfide during cycling. To address these issues, zeolitic imidazolate framework (ZIF)-derived composites have been extensively explored because of distinct advantages such as the formation of nano-sized particles, heteroatom doping, and highly porous structures. However, ZIF-derived carbon supports primarily consist of ultra-micropores that can impede lithium-ion diffusion. Herein, we aimed to enhance cycling stability by introducing a nitrogen-doped carbon quantum dot (NCQD) solution derived from N-methyl-2-pyrrolidone into cobalt-based ZIF-67 to modify the porosity and dope heteroatoms of CoS2 nanoparticle-embedded heteroatom-doped carbon composites (CoS2/NSC). The mildly acidic NCQD solution resulted in the partial etching of the ZIF-67 structure, along with the deposition of NCQDs as a nitrogen source. Notably, the pore sizes could be adjusted by varying the concentration of the NCQD solution, while retaining the nitrogen functional groups during carbonization. The electrode using CoS2/NSC with the 2.8 mL NCQD pre-treatment exhibited enhanced C-rate capability with the capacity of 392 mAh/g at 2.0 A/g. Moreover, the cycling stability was improved, with a capacity retention of 77 % after 100 cycles.