Rechargeable Li-ion Batteries Research Articles

Chemical synthesized nano-Li3V2O5 anode for high-rate rechargeable Li-ion batteries at low temperature

Lithium-ion batteries (LIBs) are widely used and considered as an ideal power supply for different applications. However, severe power/energy loss and lithium dendrite growth at low temperatures are still major problems for the graphite-based LIBs. Here we develop a highly stable nano ω-Li3V2O5 anode (named n-LVO-H) with a suitable lithium embedding potential via a chemical method. Benefiting from a short Li+ transport path, the product n-LVO-H anode accelerates the diffusion of Li+ in the particles. In addition, a robust solid-electrolyte interface layer built on the n-LVO-H particles using 1,3-dioxolane (DOL) based electrolyte with low desolvation energy facilitates Li+ transport at the interface. Such an unconventional combination of nano-size anode material with DOL electrolyte renders the n-LVO-H cell high C-rate capacity (207.1 mAh g−1 at 10C), while enjoying cycling stability (92.93 % retention at 10C after 1000 cycles) and low-temperature tolerance (248.1 mAh g−1 at -20 °C and 0.2C) concurrently.

Design considerations and cycling guidance for aluminum foil anodes in lithium-ion rechargeable cells

Al foil is an attractive anode candidate for Li-ion rechargeable batteries, but the systemic problem of fast capacity degradation limits its re-introduction in practical applications. Partial lithiation-delithiation does mitigate the issue to a certain degree, but the cycle life is still tied to the problems associated with the phase transformation between β-LiAl and α-Al. Utilizing the solubility range of β-LiAl has been proven to be a feasible approach to stabilize the β-LiAl grown on an Al foil, i.e., the β-LiAl(Al) anode, but the electrochemically driven ion transport limitations of this electrode remain largely unclear. Herein, we present comprehensive electrochemical analyses of the β-LiAl(Al) electrode to shed light on its kinetic limitations which have intrinsic links to the electrode thickness and total cell capacity. Results show that the β-LiAl(Al) electrode can be charged at a C-rate as high as 2.9 C when a proper prelithiation is done for an Al foil. The superior rate capability is suggested to partly originate from the fast lithium diffusion in β-LiAl: -10−7 cm2·s−1 at room temperature. Furthermore, the cells consisting of β-LiAl(Al) vs. commercial Li4Ti5O12 exhibit promising cycling performances, even at 10 mA·cm−2, giving 300 cycles with a capacity retention of ∼80%. With a systematic investigation of the limiting mechanisms focusing on correlating the prelithiation depth and the cycle life, the cyclability of the β-LiAl(Al) electrode at different current densities (0.5–10 mA·cm−2) is mapped out, providing comprehensive guidance for the practical utilization of the β-LiAl(Al) anode in a range of Li-ion cell types, from all-solid-state batteries to hybrid capacitors.

Advances in Electrospun Materials and Methods for Li-Ion Batteries

Electronic devices commonly use rechargeable Li-ion batteries due to their potency, manufacturing effectiveness, and affordability. Electrospinning technology offers nanofibers with improved mechanical strength, quick ion transport, and ease of production, which makes it an attractive alternative to traditional methods. This review covers recent morphology-varied nanofibers and examines emerging nanofiber manufacturing methods and materials for battery tech advancement. The electrospinning technique can be used to generate nanofibers for battery separators, the electrodes with the advent of flame-resistant core-shell nanofibers. This review also identifies potential applications for recycled waste and biomass materials to increase the sustainability of the electrospinning process. Overall, this review provides insights into current developments in electrospinning for batteries and highlights the commercialization potential of the field.

Superior stability and electrochemical performance of Li2ZnTi3O8 anode enabled by the derivatives from the isomers of trithiocyanuric acid

Rechargeable Li-ion batteries with fast-charging performance, long cycle life and safety are desirable. Herein, an efficient hydrothermal avenue was adopted to modify Li2ZnTi3O8 (LZTO) with trithiocyanuric acid (TCA). The two isomers of keto and enol TCA undergo different evolutions in the hydrothermal and electrochemical processes. For the enol TCA in the hydrothermal process, the HS– bonds close to LZTO react with LZTO to introduce superficial S-doping to facilitate electron conductance, and the others oxidize into –SO3– groups which transform into –SO3Li groups in lithiation process to favor Li+ migration. The keto TCA is stable in the hydrothermal process, yet the CS groups oxidize into –SO3– groups in anodic process and yield –SO3Li groups in subsequent cathodic process for Li+ diffusion. Despite these changes, the six-membered cyclic structures in both the keto and enol TCA are stable and coordinate with LZTO to create coating layer. The organic coating with good mechanical performance and strong interaction with PVDF protects LZTO from electrolyte corrosion and side reactions. Therefore, the TCA-modified LZTO demonstrates accelerated Li-ion migration and electron transfer, significantly enhanced rate capability and cycling stability.

Nanoarchitecture factors of solid electrolyte interphase formation via 3D nano-rheology microscopy and surface force-distance spectroscopy

The solid electrolyte interphase in rechargeable Li-ion batteries, its dynamics and, significantly, its nanoscale structure and composition, hold clues to high-performing and safe energy storage. Unfortunately, knowledge of solid electrolyte interphase formation is limited due to the lack of in situ nano-characterization tools for probing solid-liquid interfaces. Here, we link electrochemical atomic force microscopy, three-dimensional nano-rheology microscopy and surface force-distance spectroscopy, to study, in situ and operando, the dynamic formation of the solid electrolyte interphase starting from a few 0.1 nm thick electrical double layer to the full three-dimensional nanostructured solid electrolyte interphase on the typical graphite basal and edge planes in a Li-ion battery negative electrode. By probing the arrangement of solvent molecules and ions within the electric double layer and quantifying the three-dimensional mechanical property distribution of organic and inorganic components in the as-formed solid electrolyte interphase layer, we reveal the nanoarchitecture factors and atomistic picture of initial solid electrolyte interphase formation on graphite-based negative electrodes in strongly and weakly solvating electrolytes.

Development of All-Solid-State Li-Ion Batteries: From Key Technical Areas to Commercial Use

Innovation in the design of Li-ion rechargeable batteries is necessary to overcome safety concerns and meet energy demands. In this regard, a new generation of Li-ion batteries (LIBs) in the form of all-solid-state batteries (ASSBs) has been developed, attracting a great deal of attention for their high-energy density and excellent mechanical-electrochemical stability. This review describes the current state of research and development on ASSB technology. To this end, study of the literature and patents as well as market analysis over the last two decades were carried out, highlighting how scientific achievements have informed the application of commercially profitable ASSBs. Analyzing the patents registered over the past 20 years revealed that the number of them had increased exponentially-from only few per year in early 2000 to more than 342 in 2020. Published literature and patents on the topic declare a solid-state electrolyte (SSE) to be the main component of ASSBs, and most patented examples are referred to as solid inorganic electrolytes (SIEs), followed by solid polymer electrolytes (SPEs) and solid hybrid electrolytes (SHEs) in popularity. Investigation of company websites, social media profiles, reports, and academic publications identified 93 companies associated with ASSBs. A list of leading businesses in the solid-state battery sector was compiled, out of which 36 provided information on the ASSB units in their product portfolio for detailed analysis.

Magnetic Properties of Multifunctional 7LiFePO4 under Hydrostatic Pressure

LiFePO4 (LFPO) is an archetypical and well-known cathode material for rechargeable Li-ion batteries. However, its quasi-one-dimensional (Q1D) structure along with the Fe ions, LFPO also displays interesting low-temperature magnetic properties. Our team has previously utilized the muon spin rotation (µ +SR) technique to investigate both magnetic spin order as well as Li-ion diffusion in LFPO. In this initial study we extend our investigation and make use of high-pressure µ +SR to investigate effects on the low-T magnetic order. Contrary to theoretical predictions we find that the magnetic ordering temperature as well as the ordered magnetic moment increase at high pressure (compressive strain).

Boosting the electrochemical performance of Prussian-Blue-analogue based Li-ion rechargeable batteries by the addition of Ag or Ni nanoparticles into the cathode

The poor cyclability of Prussian-blue-analogue (PBA) based rechargeable Li-ion batteries places a limitation on their practical applications. Here, we demonstrate that the addition of bare Ag or Ni nanoparticles (NPs) into the vicinity of the nano-sized PBA particles can effectively improve the electrochemical performance of the batteries, leading toward a higher energy storage capacity. The addition of 14 mass-percent of 13.6 mm Ag NPs into the vicinity of the 120 nm K0.58Co[Co(CN)6] NPs gives rise to a 260 % increase in the stabilized full specific capacity CF, and the addition of 14 mass-percent of 12.4 nm Ni NPs gives rise to an 86 % increase of the stabilized CF. The addition of Ag or Ni NPs was also found to enhance the CF for the 80 nm Na0.46Co[Fe(CN)6]-based Li-ion batteries but the effect was smaller. It is the participations of the redox reactions of weakly bonded surface electrons on the Ag/Ni NPs that enhances the energy storage capacity of the battery.

Microstructure dependent behavior of the contact interface on porous graphene wrapped Si anodes for Li-ion batteries

Si/carbon composites are attractive anode materials for rechargeable Li-ion batteries (RLIBs), which combine the advantages of Si and graphene. Designing special Si/carbon structure with intimate contact interface and abundant void space for fast ion transmission is an effective strategy for enhancing cyclability and rate performance of the electrode materials. Inspired by the structure of fishnet, here we fabricate a binder-free and self-standing Si@porous-graphene (Si@PGN60) composite with nano silicon particles encapsulated in porous graphene sheets. The obtained Si@PGN60 sample exhibits many favourable features for high performance Si/carbon anodes, including improved Si/graphene contact interface, and abundant void space for fast ion transmission. Tanks to the unique structure, the resultant Si@PGN60 anode presents remarkably improved capacity reaching 1839.9 mA h g−1 at 300 mA g−1, and excellent cycling performance (734 mA h g−1 at a high current density of 3000 mA g−1).

Understanding the Electrochemical Performances of Si Anodes Incorporating Mechanically Interlocked Binders Prepared from α-Cyclodextrin-Based Polyrotaxanes

Rechargeable Li-ion batteries with larger autonomy are needed to meet increasing market demands, hence the intensive research effort to switch from graphite to silicon (Si) anodes, despite their detrimental massive volume changes upon cycling. Many elegant polymer chemistries have addressed this issue by designing smart binders capable of buffering Si electrodes fracturing and maintaining their overall structure. In this sense, self-healing PR–PAA binders relying on the α-cyclodextrin (α-CD) supramolecular chemistry and prepared by cross-linking poly(acrylic acid) (PAA) with α-CD based polyrotaxanes (PR) have recently been proposed. We herein further explore this binder chemistry to understand the proper function of such mechanically interlocked networks. We successfully synthesized a wide range of PR–PAA binders by varying their structural parameters: the doping ratio of PR, the cross-linking density, as well as the polymer molecular weight and the PR ring coverage. Then, their electrochemical performances were tested in nano-sized Si composite electrodes, and a structure/property correlation was evidenced. By promoting the α-CD sliding motion through both an increase of the PR doping fraction and a decrease of the PR ring coverage, we succeeded in making a PR−PAA-based Si electrode having an initial capacity of >3000 mA h/g and showing 82% capacity retention after 100 cycles as opposed to only 42% for PAA-based Si electrodes. A resulting better stress dissipation was evidenced by ex situ scanning electron microscope analysis as well as operando internal stress monitoring experiments via optical sensors. Altogether, this work emphasizes the benefits that CD-based supramolecular architectures can offer to the battery community for designing self-healing binders.

Refined DFT＋[formula omitted] method for computation of layered oxide cathode materials

Transition metal oxides are widely used as cathode materials in rechargeable Li-ion batteries. Here we test the performance of the parameter-free DFT＋U method for predicting the structural parameters and electronic configuration of three materials: LiCoO2, LiNiO2 and mixed transition metal Li1.2Ni0.19Co0.19Mn0.42O2 compounds. The obtained lattice parameters and band gaps are consistent with the more computationally demanding hybrid functionals and SCAN methods. We emphasize the importance of using a realistic representation of the d orbitals to obtain the correct occupancy of these states, which are highly overestimated when the widely used atomic orbitals are applied as projectors. The applied here Wannier-type projectors result in correct occupancies, allowing for a decisive assignment of the oxidation states of cations and an improved description of the electronic structure. The applied scheme enhances predictive capabilities of the DFT＋U method for computation of electrochemically active compounds.

Unexplored Orthorhombic LiMn1–xTixO2 Cathode Materials with a Stable Atomic Site Occupancy and Phase Transition

Mn-rich orthorhombic (o)-LiMn1–xTixO2 with a stable oxygen/cation site occupancy and cycling-dependent phase transition is explored as a novel Co- and Ni-free cathode material for Li-ion rechargeable batteries. Typical o-LiMnO2 suffers from oxygen deficiency, cation mixing between Li and Mn, and monoclinic (m)-Li2MnO3 secondary phase with low conductivity. Together with these drawbacks, the gradual, irreversible phase transition from layered o-LiMnO2 into spinel-like cubic (c)-LixMnO2 (x ≈ 0.5) during repeated charge/discharge cycles degrades the cycling performance of o-LiMnO2 despite the activation of electroactive c-LixMnO2 (x ≈ 0.5). By contrast, o-LiMn1–xTixO2 consists of Ti-doped o-LiMnO2 and c-LiTiO2 as the primary and secondary phases, respectively. The presence of Ti–O bonds, stronger than the existing Mn–O bonds, improves the structural stability of Ti-doped o-LiMnO2 by reducing the imperfections of the oxygen/cation lattices (including Mn octahedral sites associated with the Jahn–Teller distortion) in Ti-doped o-LiMnO2 during the long-term synthesis under an inert atmosphere. In addition, the electrochemically inactive (>2 V vs Li+/Li) c-LiTiO2 phase with high conductivity serves as a pillar that suppresses the severe structural collapse of Ti-doped o-LiMnO2 through an abrupt phase/structural transition during cycling (2–4.5 V). As a result, o-LiMn1–xTixO2 with an optimal Ti content exhibits a higher maximum discharge capacity and superior cycling performance compared to the pristine o-LiMnO2.

Novel ternary compound transition metal dichalcogenide TiNbS4 as promising anodes materials for Li-ion batteries: A DFT study

Searching for suitable anodes with good performance is a key challenge in the development of rechargeable Li-ion batteries (LIBs). In this paper, the performance of a new two-dimensional transition metal dichalcogenide (TMDs) material TiNbS4 as anode material is systematically studied by density functional theory (DFT). Firstly, the stability of the crystal structure is verified by calculating the phonon spectra, it is also demonstrated that TiNbS4 has good electronic conductivity based on the energy band and electronic density of states, which is important for the anode material of LIBs. Secondly, the adsorption and diffusion behavior of Li on the surface of TiNbS4 is studied, and the theoretical capacity and open-circuit voltage are calculated. It exhibits a high theoretical capacity (990 mA·hg−1) that are much better than the graphite (372 mA·hg−1), and a low average open-circuit voltage (0.63 V). Combining those advanced performance, TiNbS4 monolayer sheets can be used as an ideal anode material.

Solid state lithium-ion rechargeable batteries: An overview

Rechargeable solid-state Li-ion batteries have potential for applications in mobile devices and electric vehicles in the near future to meet the growing demand for high energy storage. Research on rechargeable solid-state Li-ion batteries has a long history and has been accelerating recently. Solid electrolytes are the most important component in the all-solid-state batteries. Solid electrolytes can be divided into the following groups: oxide groups (Perovskite Li3.3La0.56TiO3, NASICON LiTi2(PO4)3, LISICON Li14Zn(GeO4)4, and Li7La3Zr2O12 garnets), sulfide groups (Li2S – P2S5 and Li2S – P2S5 – MxS), hydride group (LiBH4, LiBH4–LiX (X=Cl, Br or I), LiBH4–LiNH2, LiNH2, Li3AlH6 and Li2NH), halogen group (LiI, spinel Li2ZnI4 and anti-perovskite Li3OCl), and polymer group (mainly polyethylene). Although electrolytes with good ionic conductivity have been used, the performance of solid-state rechargeable Li-ion batteries is still far behind that of the ones using liquid electrolytes. Along with the development of science and technology, many scientific and technical problems in solid-state rechargeable Li-ion batteries have been discovered. In this review, the major issues of solid-state rechargeable Li-ion batteries will be breifly documented: the interface between the active material (AM) and the solid electrolyte (SE), aging of the solid-solid interface, electrode structure, and fabrication methods.

New Avenues for Organic Redox Materials as Sustainable Lithium-ion Battery Cathodes

As the demand for electrification of means of transportation and storage of electrical energy for later use is skyrocketing, rechargeable Li-ion batteries (LIBs) are at the heart of this revolution. Acknowledging the carbon footprints, environmental concerns and cost of the commercial cathode materials, this is the high time to advocate sustainable alternatives. This review aims at establishing the potential of organic redox-active molecules as a burgeoning class of sustainable solid cathode materials for LIBs. The materials are classified according to their structural features (molecules, metallo-organic complexes, and organic/metal–organic frameworks) and electrochemical performance to lay emphasis on practical applications and bottlenecks in commercialization. However, these materials are still in early stages of development, and new frontiers have been explored in the last five years.

Investigation of the electrochemical performance of the graphite‒silicon composite in carbonate based solvents

Nowadays, rechargeable Li-ion batteries represent almost all human activities. Therefore, the requirements of battery optimization for power density, energy density, and cycle life are becoming necessary. Based on negative commercial graphite, graphite‒silicon composite (G‒Si) material has become a potential anode for Li-ion batteries due to its high specific capacity and energy density. This paper presented the investigation the electrochemical performance of the G‒Si composite in the carbonate based solvents which consisted of 1 M LiPF6 dissolving in the solvent of EC‒DMC 1:1 (v/v), EC‒DEC 1:1 (v/v), or EC‒EMC 1:1 (v/v). The results showed that the G‒Si composite delivered a high capacity of 616.0 mAh/g with the highest capacity retention of 64.2% (50 cycles) at the current density of 40 mA/g in the EC‒EMC 1:1 (v/v) solvent. However, when the current density was doubled (80 mA/g), the capacity of G‒Si in EC‒DEC 1:1 (v/v) rapidly decreased, while the capacity of the EC‒EMC 1:1 (v/v) maintained the highest. The EIS showed that the Rsf and Rct values in the EC‒DEC 1:1 (v/v) based electrolyte gradually increased with cycles which appropriated to the GCPL results. Besides, the intercalation diffusion mechanism of Li+ into the G‒Si composite confirmed that this process could be divided into two main regions where the diffusion coefficients were the minimum and related to the plateaus in the discharge curves of G‒Si material. The diffusion coefficient of G‒Si was of 10-6‒10-12 cm2/s which was the smallest in the EC‒DEC 1:1 (v/v) system.

Anthracite coal from Vang Danh – Quang Ninh as anode material for rechargeable Li-ion batteries

This study investigated the structure of anthracite material (ATC) exploited from the Vang Danh mine (Quang Ninh) and its application as an anode for rechargeable Li-ion batteries. After the chemical treatment, the material was heated at 800 oC, 1000 oC, or 1200 oC for 2 hours, 3 hours, or 4 hours, respectively. Scanning electron microscopy (SEM) confirms that the raw material was polyhedral and sharp particles. The impurities in raw material, especially the metal compounds, was significantly reduced after the chemical-treated process. As a result, the carbon content increased from 78.91% in raw material to 86.94% in the chemical-treated sample. Regarding the structure, the Raman spectra showed that the AD/AG ratio decreased with increasing temperature and heating time. This confirmed that the more disordered structures were obtained at low temperatures and heating times. In addition, the interlayer spacing (d002) between the aromatic layers in the crystalline regions varied from 0.35 to 0.36 nm, while the lateral sizes (La) were 3.0-4.1 nm, and the stacking heights (Lc) were 1.4-2.0 nm. The ATC materials can serve as anode for rechargeable Li-ion batteries with high Coulombic efficiency (nearly 100%) and impressing capacity retention (nearly 100% after 40 cycles). Among the investigated samples, ATC 8002 delivers the highest capacity of 286.3 mAh/g with a high capacity retention of 88.5% after 40 cycles.

Intercalation of argon in honeycomb structures towards promising strategy for rechargeable Li-ion batteries

High-performance rechargeable batteries are becoming very important for high-end technologies with their ever increasing application areas. Hence, improving the performance of such batteries has become the main bottleneck to transferring high-end technologies to end users. In this study, we propose an argon intercalation strategy to enhance battery performance via engineering the interlayer spacing of honeycomb structures such as graphite, a common electrode material in lithium-ion batteries (LIBs). Herein, we systematically investigated the LIB performance of graphite and hexagonal boron nitride (h-BN) when argon atoms were sent into between their layers by using first-principles density-functional-theory calculations. Our results showed enhanced lithium binding for graphite and h-BN structures when argon atoms were intercalated. The increased interlayer space doubles the gravimetric lithium capacity for graphite, while the volumetric capacity also increased by around 20% even though the volume was also increased. The ab initio molecular dynamics simulations indicate the thermal stability of such graphite structures against any structural transformation and Li release. The nudged-elastic-band calculations showed that the migration energy barriers were drastically lowered, which promises fast charging capability for batteries containing graphite electrodes. Although a similar level of battery promise was not achieved for h-BN material, its enhanced battery capabilities by argon intercalation also support that the argon intercalation strategy can be a viable route to enhance such honeycomb battery electrodes.

Waste to Treasure: Regeneration of Porous Co-Based Catalysts from Spent LiCoO2 Cathode Materials for an Efficient Oxygen Evolution Reaction

The increasing demand for portable electronic devices and electric vehicles (EVs) has triggered the rapid growth of the rechargeable Li-ion battery (LIB) market. However, in the near future, it is predicted that a large amount of spent LIBs will be scrapped, imposing huge pressure on environmental protection and resource reclaiming. The effective recycling or regeneration of the spent LIBs not only relieves the environmental burdens but also avoids the waste of valuable metal resources. Herein, a porous Co9S8/Co3O4 heterostructure is successfully synthesized from the spent LiCoO2 (LCO) cathode materials via a conventional hydrometallurgy and sulfidation process. The fabricated Co9S8/Co3O4 catalyst exhibits high catalytic activity toward oxygen evolution reaction (OER) in an alkaline solution, with an overpotential of 274 mV to achieve the current density of 10 mA cm–2 and a Tafel slope of 48.7 mV dec–1. This work demonstrates a facile regeneration process of Co-based electrocatalysts from the spent LiCoO2 cathode materials for efficient oxygen evolution reaction.

Development of vein graphite by optimizing the NaOH concentration in alkali roasting-acid leaching process for the anode application in rechargeable Li-ion batteries

Development of vein graphite by optimizing the NaOH concentration in alkali roasting-acid leaching process for the anode application in rechargeable Li-ion batteries