Stability Of Lithium-ion Batteries Research Articles

Confined Synthesis of SnO2 Nanoparticles Encapsulated in Carbon Nanotubes for High-Rate and Stable Lithium-Ion Batteries

Confined Synthesis of SnO2 Nanoparticles Encapsulated in Carbon Nanotubes for High-Rate and Stable Lithium-Ion Batteries

Three-dimensional hierarchically porous MoS2 foam as high-rate and stable lithium-ion battery anode

Architected materials that actively respond to external stimuli hold tantalizing prospects for applications in energy storage, wearable electronics, and bioengineering. Molybdenum disulfide, an excellent two-dimensional building block, is a promising candidate for lithium-ion battery anode. However, the stacked and brittle two-dimensional layered structure limits its rate capability and electrochemical stability. Here we report the dewetting-induced manufacturing of two-dimensional molybdenum disulfide nanosheets into a three-dimensional foam with a structural hierarchy across seven orders of magnitude. Our molybdenum disulfide foam provides an interpenetrating network for efficient charge transport, rapid ion diffusion, and mechanically resilient and chemically stable support for electrochemical reactions. These features induce a pseudocapacitive energy storage mechanism involving molybdenum redox reactions, confirmed by in-situ X-ray absorption near edge structure. The extraordinary electrochemical performance of molybdenum disulfide foam outperforms most reported molybdenum disulfide-based Lithium-ion battery anodes and state-of-the-art materials. This work opens promising inroads for various applications where special properties arise from hierarchical architecture.

Cage-like Silicene/CNT Microspheres Synthesized by a Topochemical Reaction as Anodes for Enhanced Stable Lithium-Ion Batteries

Silicene has recently received increasing attention as an anode material in lithium-ion batteries (LIBs) due to its unique architectural properties. However, the synthesis of silicene still remains challenging, which limits its practical applications. In this work, silicene nanosheets with multilayer stacks are synthesized by the topochemical method and successfully combined with carbon nanotubes (CNTs) to form a cage-like structure composite. Benefiting from the hierarchical structure and two-dimensional active material, the cage-like silicene/CNTs increases the ionic and electric conductivity while reducing the volume expansion and relieving swelling stress. In addition, calculation also indicates a lower diffusion energy barrier of lithium ions in silicene than that in bulk silicon, which ultimately enhances the rate and cycling performance of the battery. The as-obtained electrodes exhibit a capacity of 690 mA h g–1 at 1 A g–1 after 500 cycles. This work not only introduces a facile topochemical method to prepare materials with two-dimensional multilayer silicene but also provides a new strategy for the application of silicene in LIBs.

Pr doped single-crystal LiNi0.5Mn0.3Co0.2O2 cathode enables high rate capability and cycle stability for lithium ion batteries

The massive application of single crystal (SC) ternary cathode material LiNi1-x-yMnxCoyO2 is largely restricted by the unsatisfactory rate capability which is caused by the sluggish Li+ diffusion and structural instability. Herein, Pr3+, a large radius ion is introduced to single-crystal LiNi0.5Mn0.3Co0.2O2 to enhance Li + conductivity and structural stability. With 0.4% Pr doping, the Li(Ni0.5Mn0.3Co0.2)0.996Pr0.004O2 cathode displays a capacity retention of 79.72% at 10 C, and a 98.17% capacity retention after 50 cycles at 25 °C and 96.3% capacity retention after 50 cycles at 55 °C within a 3.0–4.5 V voltage window. Electrochemical impedance spectroscopy confirms that the Pr doping can effectively lower the charge-transfer resistance and facilitate the transportation of Li+ on the surface of LiNi0.5Mn0.3Co0.2O2. The Direct current internal resistance result implies that the structure of the Pr-doped cathode particles is more stable during cycling. In addition, differential scanning calorimetry measurements measurement combined with in situ X-ray diffraction confirms the thermo-stabilization effect of the Pr dopant.

Enhanced high-voltage robustness of ultra-high nickel cathodes by constructing lithium-ion conductor buffer layer for highly stable lithium-ion batteries

Ultra-high nickel layered oxide cathode materials, of much interest due to their higher energy density and price advantages, have become one of the key development directions of cathode materials for lithium-ion batteries. However, a critical challenge for commercial applications is the rapid capacity fading and severe structural degradation, especially at the high cut-off voltage, which originates from interfacial instability and irreversible phase transition. Here we designed a protective Li3PO4 buffer layer modified ultra-high nickel cathode materials LiNi0.92Co0.04Mn0.04O2 (denoted as NCM9) to dramatically improve high-voltage robustness and structural stability through a mild synchronous lithium strategy. Our results affirmed that the Li3PO4 buffer layer plays an undeniable role in suppressing the capacity and structural degradation, and found that it effectively alleviates the irreversibility of the H2-H3 phase transition of the ultra-high nickel cathode material and enhances mechanical and interfacial stability. Additionally, the main exothermic peak temperature of the modified sample at 256.86 °C was higher than that of the pristine sample at 236.86 °C, which fully confirms the significant improvement of the thermal stability of the modified sample. This work provides additional insights into the complex mechanism of high-voltage robustness and improved structural stability of ultra-high nickel cathodes at high cut-off voltage.

Enabling Long-Cycling Life of Si-on-Graphite Composite Anodes via Fabrication of a Multifunctional Polymeric Artificial Solid-Electrolyte Interphase Protective Layer.

The energy density of lithium-ion batteries (LIBs) can be meaningfully increased by utilizing Si-on-graphite composites (Si@Gr) as anode materials, because of several advantages, including higher specific capacity and low cost. However, long cycling stability is a key challenge for commercializing these composites. In this study, to solve this issue, we have developed a multifunctional polymeric artificial solid-electrolyte interphase (A-SEI) protective layer on carbon-coated Si@Gr anode particles (making Si@Gr/C-SCS) to prolong the cycling stability in LIBs. The coating is made of sulfonated chitosan (SCS) that is crosslinked with glutaraldehyde promoting good ionic conduction together with sufficient mechanical strength of the A-SEI. The focused ion beam-scanning electron microscopy and high-resolution transmission electron microscopy images show that the SCS is uniformly coated on the composite particles with thickness in nanometer. The anodes are investigated in Li metal cells Si@Gr/C-SCS||Li metal) and lithium-ion full-cells (LiNi0.6Co0.2Mn0.2O2 (NCM-622)||Si@Gr/C-SCS) to understand the material/electrode intrinsic degradation as well as the impact of the polymer coating on active lithium losses because of the continuous SEI (re)formation. The anode composites exhibit a high capacity reaching over 600 mAh g-1, and even without electrolyte optimization, the Si@Gr/C-SCS illustrates a superior long cycle life performance of up to 1000 cycles (over 67% capacity retention). The excellent long-term cycling stability of the anodes was attributed to the SCS polymer coating acting as the A-SEI. The simple polymer coating process is highly interesting in guiding the preparation of long-cycle-life electrode materials of high-energy LIB cells.

A quasi-solid-state electrolyte with high ionic conductivity for stable lithium-ion batteries

A quasi-solid-state electrolyte with high ionic conductivity for stable lithium-ion batteries

Key Factor Determining the Cyclic Stability of the Graphite Anode in Potassium-Ion Batteries

Graphite is the most commonly used anode material for not only commercialized lithium-ion batteries (LIBs) but also the emerging potassium-ion batteries (PIBs). However, the graphite anode in PIBs using traditional dilute ester-based electrolyte systems shows obvious capacity fading, which is in contrast with the extraordinary cyclic stability in LIBs. More interestingly, the graphite in concentrated electrolytes for PIBs exhibits outstanding cyclic stability. Unfortunately, this significant difference in cycling performance has not raised concern up to now. In this work, by comparing the cyclic stability and graphitization degree of the graphite anode upon cycling, we reveal that the underlying mechanism of the capacity fading of the graphite anode in PIBs is not the larger volume expansion of graphite caused by the intercalation of potassium ions but the continual accumulation of the solid electrolyte interphase (SEI) on the surface of graphite. By X-ray photoelectron and nuclear magnetic resonance spectroscopies combined with chemical synthesis, it is concluded that the accumulation of the SEI may mainly come from the continual deposition of a kind of oligomer component, which blocks intercalation and deintercalation of potassium ions in graphite anodes. The designed SEI-cleaning experiment further verifies the above conclusion. This finding clarifies the crucial factor determining the cyclic stability of graphite and provides scientific guidance for application of the graphite anode for PIBs.

Mesoporous TiNb2O7 nanosheets anode with excellent rate capability and cycling performance in lithium ion half/full batteries

The Wadsley-Roth phase TiNb2O7 has attracted considerable attention because of its high intercalation potential and excellent cycle capability. However, the poor electronic conductivity and sluggish ionic diffusion kinetics hinder its commercial application. Herein, a novel mesoporous TiNb2O7 nanosheet (MS-TNO) is fabricated via solvothermal and subsequent calcination process. Two-dimensional mesoporous nanostructures can effectively shorten transport path of lithium ions and enhance charge transfer. Galvanostatic intermittent titration technique (GITT) test shows the values of Li+ diffusion coefficient during discharge/charge vary in range of 10−12–10−11 cm2 S−1, indicating high efficient Li+ diffusion pathways in the lattice. In situ X-ray diffraction experiment elucidates the insertion/extraction of Li+ in MS-TNO is highly reversible, with a unit-cell volume change of 7.22% after Li+ insertion. Consequently, MS-TNO material delivers significant surface-controlled capacitive behavior and excellent electrochemical performances. These results clearly demonstrate that the MS-TNO is a promising anode material for rapid-charging, high capacity, safe and stable lithium ion batteries.

Camphene-derived hollow and porous nanofibers decorated with hollow NiO nanospheres and graphitic carbon as anodes for efficient lithium-ion storage

A synthesis strategy for hollow and porous nanofibers comprising hollow NiO (H-NiO) nanospheres formed via nanoscale Kirkendall diffusion and supported over a porous graphitic carbon matrix (H-NiO@HNFs) is reported herein to enable the fabrication of advanced anodes for stable lithium-ion batteries (LIBs). The H-NiO@HNFs comprising 1D longitudinal hollow channels ensured efficient diffusion of charged species via effective electrolyte percolation besides providing sufficient space to accommodate the large volume variations during repeated cycling. The hollow NiO nanospheres acted as chemical sites for lithiation and delithiation. Additionally, the H-NiO@HNFs exhibited improved lithium-ion storage properties, such as reasonable rate capability, stable prolonged cyclability at a high current density (1.0 A g-1), and a high lithium-ion diffusion coefficient, primarily owing to their enhanced structural integrity compared to that of filled NiO nanofibers (F-NiO NFs). This facile synthesis approach could broaden the current understanding of 1D hollow nanostructures decorated with conventional hollow metal-oxide nanoparticles for various applications.

Bifunctional coating layer on Ni-rich cathode materials to enhance electrochemical performance and thermal stability in lithium-ion batteries

In this study we use N,N′-bismaleimide-4,4′-diphenylmethane (BMI), trithiocyanuric acid (TCA), and Jeffamine®-M1000 (molar ratio: 2:1:1; BTJ211) as a novel hybrid oligomer additive and surface modifier for coating (at concentrations of ca. 0.5–2 wt.%) of the cathode material LiNi0.80Co0.15Al0.05O2 (NCA) for lithium-ion batteries (LIBs). Qualitative analysis (1H NMR spectroscopy) confirms the polymerization of the BTJ additive. Morphological analyses (scanning electron microscopy/energy dispersive spectroscopy and high-resolution transmission electron microscopy) reveal that the hybrid oligomer is coated uniformly on the surface of the NCA, forming a BTJ@NCA powder material. Coin-type cells incorporating the 1 wt% BTJ@NCA electrode exhibit a significantly improved capacity retention (CR%) of 80.3%, relative to that of the bare NCA electrode (62.1%), at 1 C for 100 cycles at an upper voltage of 4.5 V. Electrochemical impedance spectroscopy and cyclic voltammetry reveal that this superior electrochemical performance originated from a lower charge transfer resistance (678.3 Ω vs. 349.6 Ω), improving Li+ ion diffusivity, and a lower polarization potential (242.9 mV vs. 368.9 mV). Furthermore, operando microcalorimetry of the cells containing the BTJ@NCA electrodes reveals that the modified electrodes can effectively decrease heat release by 69.6% when charging.

Recycling Waste Al–Si Alloy for Micrometer-Sized Spongy Si with High Areal/Volumetric Capacity and Stability in Lithium-Ion Batteries

Recycling Waste Al–Si Alloy for Micrometer-Sized Spongy Si with High Areal/Volumetric Capacity and Stability in Lithium-Ion Batteries

Cobalt-free nickel-rich layered LiNi0.9Al0.1-xZrxO2 cathode for high energy density and stable lithium-ion batteries

BackgroundTo meet the challenges of limited resources and the toxicity of cobalt, cobalt freed Ni-rich layered cathode materials for high energy density power batteries have become a hot spot. However, the poor stability upon cycling hindered their applications. MethodsA layered Zr-introduced Ni-Al based Co-free cathode material LiNi0.9Al0.1-xZrxO2 (NAZ) is designed and synthesized with a sol-gel method. Significant findingsThe prepared Co-free cathode material exhibits perfect crystal structure stability and electrochemical performance, which are attributed to the incorporation of Zr4+ with high-valence and strong Zr-O bond energy. The obtained LiNi0.9Al0.08Zr0.02O2 (NAZ-2) shows a first discharge capacity of 177.5 mAh g−1 at 1 C, and maintains about 92.45 % after 100 charge / discharge cycles. It also displays a high specific capacity of 160 mAh g−1 at 5 C. Furthermore, compared to the pure sample, LiNi0.9Al0.08Zr0.02O2 (NAZ-2) shows a lower charge transfer impedance of 57.90 Ω and larger diffusion coefficient of lithium ions of 5.70217 × 10−9 cm2 S−1, which is conducive to the migration of Li+ and the inhibiting of the polarization.

A Single-Layer Composite Separator with 3D-Reinforced Microstructure for Practical High-Temperature Lithium Ion Batteries.

Incorporation of ceramic materials into separators has been frequently applied in both research and industry to improve the overall high-temperature performances of lithium ion batteries. However, inorganic ceramic particles tend to form aggregation in separators and even fall off in the separator matrix due to the inferior combination between ceramic particles and polymer matrix, giving rise to a decrease in separator porosity and thus the degradation of battery performances. Herein, a single-layer core-shell architecture is designed to reinforce the polymer matrix through encircling Al2 O3 particles by poly(vinylidene fluoride) with strong inter-molecular interaction. The 3D-reinforced microstructure effectively improves pore distribution and thermal stability to resist the dimensional deformation at high temperatures, thus giving rise to a high Coulombic efficiency of 99.16% and 87.5% capacity retention after 500 cycles at 80°C for LiFePO4 /Li batteries. In particular, the excellent performances of the proposed separator microstructure are confirmed with a thickness value of commercial separators. This work provides a promising strategy to fabricate a core-shell structural composite separator for stable lithium ion batteries at high temperatures.

Correlative Electrochemical Microscopy for the Elucidation of the Local Ionic and Electronic Properties of the Solid Electrolyte Interphase in Li-Ion Batteries.

The solid‐electrolyte interphase (SEI) plays a key role in the stability of lithium‐ion batteries as the SEI prevents the continuous degradation of the electrolyte at the anode. The SEI acts as an insulating layer for electron transfer, still allowing the ionic flux through the layer. We combine the feedback and multi‐frequency alternating‐current modes of scanning electrochemical microscopy (SECM) for the first time to assess quantitatively the local electronic and ionic properties of the SEI varying the SEI formation conditions and the used electrolytes in the field of Li‐ion batteries (LIB). Correlations between the electronic and ionic properties of the resulting SEI on a model Cu electrode demonstrates the unique feasibility of the proposed strategy to provide the two essential properties of an SEI: ionic and electronic conductivity in dependence on the formation conditions, which is anticipated to exhibit a significant impact on the field of LIBs.

MoO2 Nanoparticles Decorated MoS2 Nansheets Encapsulated on MXene as Advanced Anode for Ultrafast and Stable Lithium Ion Batteries

MoO2 Nanoparticles Decorated MoS2 Nansheets Encapsulated on MXene as Advanced Anode for Ultrafast and Stable Lithium Ion Batteries

Bio-inspired synthesis of transition-metal oxide hybrid ultrathin nanosheets for enhancing the cycling stability in lithium-ion batteries

Bio-inspired synthesis of transition-metal oxide hybrid ultrathin nanosheets for enhancing the cycling stability in lithium-ion batteries

Hybrids gel electrolytes with pending polyhedral oligomeric silsesquioxane toward improving interfacial stability for lithium ion batteries

Hybrids gel electrolytes with pending polyhedral oligomeric silsesquioxane toward improving interfacial stability for lithium ion batteries

Mesoporous Single-Crystal Lithium Titanate Enabling Fast-Charging Li-Ion Batteries.

There remain significant challenges in developing fast-charging materials for lithium-ion batteries (LIBs) due to sluggish ion diffusion kinetics and unfavorable electrolyte mass transportation in battery electrodes. In this work, a mesoporous single-crystalline lithium titanate (MSC-LTO) microrod that can realize exceptional fast charge/discharge performance and excellent long-term stability in LIBs is reported. The MSC-LTO microrods are featured with a single-crystalline structure and interconnected pores inside the entire single-crystalline body. These features not only shorten the lithium-ion diffusion distance but also allow for the penetration of electrolytes into the single-crystalline interior during battery cycling. Hence, the MSC-LTO microrods exhibit unprecedentedly high rate capability, achieving a specific discharge capacity of ≈174 mAh g-1 at 10 C, which is very close to its theoretical capacity, and ≈169 mAh g-1 at 50 C. More importantly, the porous single-crystalline microrods greatly mitigate the structure degradation during a long-term cycling test, offering ≈92% of the initial capacity after 10000 cycles at 20 C. This work presents a novel strategy to engineer porous single-crystalline materials and paves a new venue for developing fast-charging materials for LIBs.

Two-dimensional hierarchical porous carbons with mesopore-enriched architectures for high-reactivity and stable lithium-ion full batteries

Two-dimensional hierarchical porous carbons with mesopore-enriched architectures for high-reactivity and stable lithium-ion full batteries