High-performance Lithium-ion Batteries Research Articles

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.

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 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.

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, we propose a design idea for a covalently bonded lateral/vertical black phosphorus (BP)-graphdiyne oxide (GDYO) heterostructure achieved through a facile ball-milling approach. Lateral heterogeneity is realized by the sp2-hybridized mode P-C bonds, which connects 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, we clarified 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. 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 are universal and represents a conceptual advance in building high-performance LIBs electrode. This article is protected by copyright. All rights reserved.

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.

Novel amide-based deep eutectic solvent electrolytes for high-performance lithium-ion batteries

The electrolytes of lithium-ion batteries (LIBs) directly affect their performance, safety, and reliability. However, existing electrolytes are still limited in terms of safety, performance, and environmental friendliness, constraining further development and application of LIBs. Herein, novel electrolytes based on a deep eutectic solvent consisting of LiTFSI [lithium bis(trifluoromethane)sulfonylimide] and DMA(N,N'-dimethylacetamide) were developed for LIBs. The results from thermogravimetry analysis, infrared spectroscopy, Raman scattering, UV-visible NIR diffuse reflectance, optical and scanning electron microscopy, and electrochemistry all showed safe, nonflammable, nontoxic, and environmentally friendly electrolytes with good thermal stability, enhanced electrochemical stability, and excellent lithium-ion conductivity. Cyclic voltammetry and electrochemical impedance spectroscopy confirmed electrolytes with rapid transport of lithium ions and stable electrochemical interface formation. The electrolytes showed good compatibility with the LiFePO4 cathode, effectively protecting the structure of the LiFePO4 electrode. The first discharge capacity of LiTFSI-DMA deep eutectic electrolyte reached as high as 156.6 mAh g−1, with a discharge capacity after 365 cycles at 1C current density reaching 142.6 mAh g−1 and a capacity retention rate of more than 91%. Overall, LiTFSI-DMA deep eutectic electrolytes with superior performance and compatibility have the potential as high-performance nonflammable electrolytes for improved LIBs.

In Situ Constructed Spinel Layer Stabilized Upcycled LiCoO2 for High Performance Lithium-Ion Batteries.

With ever-increasing requirements for cathodes in the lithium-ion batteries market, an efficiency and eco-friendly upcycling regeneration strategy is imperative to meet the demand for high-performance cathode materials. Herein, a facile, direct and upcycling regeneration strategy is proposed to restore the failed LiCoO2 and enhance the stability at 4.6 V. Double effects combination of relithiation and outside surface reconstruction are simultaneously achieved via a facile solid-phase sintering method. The evolution process of the Li-supplement and grain-recrystallization is systematically investigated, and the high performance of the upcycled materials at high voltage is comprehensively demonstrated. Thanks to the favorable spinel LiCoxMn2-xO4 surface coating, the upcycled sample displays outstanding electrochemical performance, superior to the pristine cathode materials. Notably, the 1% surface-coated LiCoO2 achieves a high discharge-specific capacity of 207.9 mA h g-1 at 0.1 C and delivers excellent cyclability with 77.0% capacity retention after 300 cycles. Significantly, this in situ created spinel coating layer can be potentially utilized for recycling spent LiCoO2, thus providing a viable, promising recycling strategy insights into the upcycling of degraded cathodes.

Dynamically constructing robust cathode-electrolyte-interphase on nickel-rich cathode by organic boron additive for high-performance lithium-ion batteries

Nickel-rich ternary cathode materials LiNi0.8Co0.1Mn0.1O2 (NCM811) have attracted broad attention due to their high voltage and high energy density for lithium-ion batteries. However, rapid capacity decay due to unstable particle surface inhibit the application. Artificial cathode electrolyte interface (CEI) is undoubtedly a more effective and simpler way to solve this issue. Here, stable and highly conductive in situ CEI is designed using a low-cost organic boron additive isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (ITD). Higher occupied molecular orbital energy endows ITD ability to participate in forming CEI. ITD-contained CEI can reduce nickel dissolving, resulting in a lower self-discharge rate, which is benefit from the uniform and stable CEI on the NCM811 surface. As expected, ITD-based CEI can restrain NCM811crystal cracking in Li||NCM811 half batteries, improving capacity retention from 29.4 % to 93.0 % after 200 cycles at 1C (1C = 200 mA g−1). It is worth mentioning that ITD–derived CEI is conducive to ion migration, which improve the rate capacity retention from 91.5 % to 95.5 %.

A hierarchical porous structure and nitrogen-doping jointly enhance the lithium-ion storage capacity of biomass-derived carbon materials

Biomass-derived carbon materials are considered potential lithium-ion anode materials because they are sustainable, renewable, economical, and environmentally friendly and have tunable microstructures. However, biomass-derived carbon materials have low specific capacity and show capacity degradation during long-term electrochemical cycling, which prevents their application in high-performance lithium-ion batteries. Hence, in this paper, nitrogen-doped hierarchical porous carbon (NHPC) is synthesized from a biomass waste material, corncob, through one-step activation and carbonization procedures. N-doping in the NHPC modifies the electron distribution on the surface of carbon, resulting in the generation of additional lithium-ion storage sites and enhancing electrode wettability to increase the conductivity. Additionally, the doping procedure results in a hierarchical porous structure with an increased specific surface area and pore volume, which facilitates ion transport and provides remarkable cycling stability. The electrochemical performance of NHPC is improved by the jointly beneficial combination of N-doping and the hierarchical porous structure. The optimized NHPC electrode provides a reversible specific capacity of 700 mAh g−1 after 100 cycles at 100 mA g−1. This study provides a simple and efficient method for improving the electrochemical properties of biomass-derived carbon materials through elemental doping and modulation of microscopic morphology and structure.

Co-doping strategies for advanced solid state electrolytes with lithium salt: a study on the structural and electrochemical properties of LATP

The commercialization of lithium-ion batteries has revolutionized the field of energy storage, yet their usage of organic electrolytes has led to significant safety concerns. Solid-state electrolytes have emerged as a promising solution to these issues, enabling the development of high-performance solid-state lithium batteries. The NASICON-type solid electrolyte Li1.3Al0.3Ti1.7P3O12 (LATP) has demonstrated excellent properties and significant potential. This study involves the solid-state synthesis of LATP electrolytes doped with Cobalt and Silicon. Furthermore, adding 8% LiBr into LATP-0.04 significantly enhanced ionic conductivity, reaching a value of 3.50 × 10−4 S cm−1. This can be linked to lithium salt filling vacant spaces between grains, resulting in a significant drop in grain boundary resistances. The electrochemical analysis through Linear Sweep Voltammetry (LSV) indicates that the investigated material demonstrates the capability to sustain stability and functionality even under the influence of elevated voltages, notably up to 5.45 V. These findings imply that optimal cobalt doping and Lithium salt contribute to superior ionic conductivity compared to pristine LATP.

SEI/dead Li-turning capacity loss for high-performance anode-free solid-state lithium batteries

Anode-free solid-state lithium metal batteries (AF-SSLBs) have the potential to deliver higher energy density and improved safety beyond lithium-metal batteries. However, the unclear mechanism for the fast capacity decay in AF-SSLBs, either determined by dead Li or solid electrolyte interface (SEI), limits the proposal of effective strategies to prolong cycling life. To clarify the underlying mechanism, herein, the evolution of SEI and dead Li is quantitatively analyzed by a solid-state nuclear magnetic resonance (ss-NMR) technology in a typical LiPF6-based polymer electrolyte. The results show that the initial capacity loss is attributed to the formation of SEI, while the dead Li dominates the following capacity loss and the growth rate is 0.141 mA h cm−2 cycle−1. To reduce the active Li loss, the combination of inorganic-rich SEI and self-healing electrostatic shield effect is proposed to improve the reversibility of Li deposition/dissolution behavior, which reduces the capacity loss rate for the initial SEI and following dead Li generation by 2.3 and 20.1 folds, respectively. As a result, the initial Coulombic efficiency (ICE) and stable CE increase by 15.1% and 15.3% in Li-Cu cells, which guides the rational design of high-performance AF-SSLBs.

High-performance room temperature solid-state lithium battery enabled by PP-PVDF multilayer composite electrolyte

High-performance room temperature solid-state lithium battery enabled by PP-PVDF multilayer composite electrolyte

Nano-silicon embedded in mildly-exfoliated graphite for lithium-ion battery anode materials

Silicon-based materials have a high theoretical specific capacity and a low discharge potential, whereas the significant capacity fading owing to weak conductivity and volume exfoliation effect. The co-utilization of silicon and graphite has become a feasible method for realizing high-performance lithium-ion batteries (LIBs). Herein, the C@p-Si/ESG composite anode material with “sandwich” structure was obtained by electrostatic assembly of mildly-exfoliated graphite and electrostatic modified nano silicon, and subsequent coated with amorphous carbon on the surface of the material. The carbon coating and the mildly-exfoliated graphite form a buffer space, which alleviates the volume expansion effect of silicon in the process of lithium alloying. In addition, the SEI film is generated outside the carbon layer, reducing the consumption of the electrolyte and the occurrence of side reactions. C@p-Si/ESG exhibits a high charge–discharge rate and an excellent long-term cycle stability.

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.

Fluorine-ion-regulated yolk–shell carbon-silicon anode material for high performance lithium ion batteries

Silicon is considered as the next-generation anode material for lithium-ion batteries due to its high theoretical specific capacity and abundant crustal abundance. However, its poor electrical conductivity results in slow diffusion of lithium ions during battery operation. Simultaneously, the alloying process of silicon undergoes a 300 % volume change, leading to structural fractures in silicon during the cycling process.As a result, it loses contact with the current collector, continuously exposing active sites, and forming a sustained solid electrolyte interface (SEI) membrane. This paper presents the design of a fluorine-ion-regulated yolk–shell carbon-silicon anode material, highlighting the following advantages: (a) Alleviating volume changes through the design of a yolk–shell structure, thereby maintaining material structural integrity during cycling. (b) Carbon shell prevents silicon from coming into contact with the electrolyte, simultaneously improving silicon's electrical conductivity and increasing ion/electron conductivity. (c) Utilizing fluorine-ion interface modification to obtain an SEI membrane rich in fluorine components (such as LiF), thereby enhancing its long cycling performance. The F-Si@Void@C exhibits outstanding electrochemical performance, with a reversible capacity of 1166 mAh/g after 900 cycles at a current density of 0.5 A/g.

Experimental study on the internal short circuit and failure mechanism of lithium-ion batteries under mechanical abuse conditions

The safety issues of lithium-ion batteries under mechanical abuse conditions have attracted widespread attention due to their high uncertainty and risk. This research takes cylindrical lithium-ion batteries as the research object and conducts three-point bending tests on cylindrical lithium-ion batteries with different states of charge (SOC), electrode thicknesses and electrode materials. The mechanical response, voltage changes, temperature changes during the loading process of the battery, and the microstructural changes of the battery's electrodes and separator after the bending test were examined. The results show that the maximum load-bearing capacity of the battery and the displacement corresponding to the short circuit decreases with the SOC of battery; the higher the battery SOC means a faster average temperature rise rate of the battery. When the SOC is higher than 60 %, the battery will experience violent thermal runaway phenomena such as explosions and spouting fire after bending tests. The mass loss rate of the battery is also greatly affected by the battery SOC and the electrode thickness, however, electrode material have almost no effect on the mass loss rate of the battery. According to the SEM images of the electrodes, it is found that short circuits cause graphite particles to break, separators to close and electrolytes oxidize on the surface of positive electrode particles. After triggering the internal short circuit, more broken particles are observed in the positive electrode material of the battery with thicker electrodes and the surface roughness of the broken particles is higher. By comparing the electrode changes of LFP and NCM, it is found that the intensity of the internal electrochemical reactions in NCM is far greater than that in LFP. The research results provide theoretical insights for understanding the electrothermal characteristics and mechanical integrity of lithium-ion batteries under mechanical abuse, which can shed light on the design and optimization of high-performance and safe lithium-ion batteries.