Rechargeable Lithium Batteries Research Articles

Synthesizing copper-doped silicon/carbon composite anode as cost-effective active materials for Li-ion batteries

Potentially useful anodic material with prospects for use within rechargeable lithium-ion batteries are fabricated from silicon (Si)-based compounds. The active Si/electrolyte contact and weak conductivity, however, constantly produce side reactions, which dramatically reduce cycling stability. The only metallic current collector that demonstrates to facilitate lithium-ion transfer and electron conduction without alloying reactions is copper (Cu). In this study, we created Si-based multicomponent anode materials made of Si/Cu/Cu3Si alloy nanoparticles (Si/Cu/Cu3Si@C) coated in amorphous carbon. This is accomplished utilizing a straightforward, low-cost approach that combines hydrothermal technology and high-intensity ball milling. To further increase conductivity, Si/Cu/Cu3Si alloy is used as the active component. Through the use of a micro-sized amorphous carbon-coated structure, the volume problem of the active material can be successfully resolved. Additionally, the micro-sized amorphous carbon may inhibit nanoparticle agglomeration and alloy interfacial side reactions. As a result, it is anticipated that the Si/Cu/Cu3Si@C composite will display favorable electrochemical performances and possess a remarkable reversible specific capacity of 984 mAh g−1 at 0.5 C. The GITT test is used to determine the DLi+ of the Si/Cu/Cu3Si@C electrode, which ranges from 10−11 to 10−8 cm−2 s−1. Additionally, the full-cell is constructed by coupling a Li(Ni1/3Co1/3 Mn1/3)O2(NCM111) cathode with a solution-based chemically Si/Cu/Cu3Si@C anode that exhibits an enhanced initial coulombic efficiency (84.9%) and outstanding cycle performance.

Size- and temperature-dependent mechanical properties of metallic lithium

Lithium (Li) metal anodes are under active investigation to boost the energy density of rechargeable lithium-ion batteries (LIBs). In developing such anodes, uncontrolled Li plating/stripping remains a critical issue, which calls for a deep understanding of the deformation characteristics of Li. Here we report an experimental study on the elastic, plastic, and creep behavior of metallic Li over a wide range of temperatures and length scales that are relevant to battery applications. We characterized these mechanical properties via environmentally controlled, variable-temperature nanoindentation. A strong size effect on the indentation hardness of Li was observed and rationalized by a modified Nix–Gao model incorporating the effect of surface energy. Size- and temperature-dependent creep behavior of Li was also analyzed and attributed to self-diffusion-controlled dislocation climb as the dominant creep mechanism.

Imaging the Surface/Interface Morphologies Evolution of Silicon Anodes Using in Situ/Operando Electron Microscopy

Si-based rechargeable lithium-ion batteries (LIBs) have generated interest as silicon has remarkably high theoretical specific capacity. It is projected that LIBs will meet the increasing need for extensive energy storage systems, electric vehicles, and portable electronics with high energy densities. However, the Si-based LIB has a substantial problem due to the volume cycle variations brought on by Si, which result in severe capacity loss. Making Si-based anodes-enabled high-performance LIBs that are easy to utilize requires an understanding of the fading mechanism. Due to its distinct advantage in morphological changes from microscale to nanoscale, even approaching atomic resolution, electron microscopy is one of the most popular methods. Based on operando electron microscopy characterization, the general comprehension of the fading mechanism and the morphology evolution of Si-based LIBs are debated in this review. The current advancements in compositional and structural interpretation for Si-based LIBs using advanced electron microscopy characterization methods are outlined. The future development trends in pertinent silicon materials characterization methods are also highlighted, along with numerous potential research avenues for Si-based LIBs design and characterization.

A Novel Graphene Based Bi-Function Humidity Tolerant Binder for Lithium-Ion Battery.

Binders play a critical role in rechargeable lithium-ion batteries (LIBs) by holding granular electrode materials, conductive carbons, and current collectors firmly together to form and maintain a continuous electron conduction phase with sufficient mechanical strength. In the commercial LIBs, the dominant binder is polyvinylidene fluoride for the cathode (LiCoO2 , LiFePO4 , LiNix Coty Mnz O2 , etc.) and carboxyl methylcellulose/styrene-butadiene rubber for the anode (graphite and Li4 Ti5 O12 ). However, these polymer binders have several drawbacks, particularly, a lack of electronic and lithium-ion conductivities. Here, a novel organic/inorganic hybrid conductive binder (LAP-rGO) for both the anode and cathode of LIBs is reported. The binder consists of 2D reduced graphene oxide sheets with anchored long alkane chains. Electrodes prepared using this binder exhibit sufficient high bond strength, fast electrolyte diffusion, high rate charge/discharge performance, and excellent cycling stability. Around 130 mAh g-1 capacity enhancement at 5C is demonstrated for LiFePO4 and Li4 Ti5 O12 electrodes owing to the combined improvement in electron and lithium ion transportation. LAP-rGO bond graphite anode shows specific capacity beyond its theoretical value. Electrode slurries prepared using this new binder have superior processing and coating properties that can be prepared under a high humidity and dried using less energy.

Tuning Electrochemical Properties of Nitroaromatic Cathodes by Function‐Oriented Design for Rechargeable Lithium‐Ion Batteries

AbstractRechargeable lithium‐ion batteries (LIBs) based on organic cathodes are an attractive alternative energy storage technology owing to the low cost and sustainability. Recently, nitro functionality in dinitrobenzenes is successfully demonstrated as an electrochemically reversible high‐capacity redox group. In this study, a function‐oriented design is employed to further disclose the effects of substituting functional groups and molecular conjugate structures on electrochemical properties of a range of nitroaromatic derivatives as organic cathodes for rechargeable LIBs. In specific, it is revealed that the redox potential of nitroaromatic cathodes can be effectively adjusted by introducing distinct electronically inducible functional groups, while the cyclic life can be significantly prolonged with the introduction of the hydrophilic groups. When constructed with extended π‐conjugated structures, the electronic conductivity and electrochemical kinetics of nitroaromatics are increased significantly owing to their various long‐range π–π stacking. Moreover, density‐functional theory calculations further provide theoretical insights into the distinct electrochemical behaviors of the various nitroaromatics in the molecular level. This is the first study that reveals the influences of substituting groups and conjugated structures on the electrochemical performance of nitroaromatic cathode materials, which enables a function‐oriented molecular design of such organic materials and sheds light on their future development.

The Impact of Nanotechnology on Lithium-Ion Battery Used in Electric Vehicles

The global environment has already been polluted by the traditional fuel vehicles and become more and more serious. In this situation, the electric vehicles (EVs) came to the attention of the worldwide people. In recent years, the electric vehicles have developed rapidly. As a result, the components of the electric vehicles were logically achieved great success, particularly the rechargeable lithium-ion battery. Fortunately, the nanotechnology, at the same time, made a great deal of huge achievements and appeared in numerous fields. Nanotechnology obviously plays a critical role in the field of lithium-ion battery and nearly all elements of lithium-ion battery are changed to varying degrees. The performances of lithium-ion are becoming more suitable for commercial production, such as higher power and energy density, lower price, better stability and increased capacity. The recent and advanced developments of different kinds of welcomed anode materials, graphite, nanostructural silicon, lithium titanate and titanium dioxide, and cathode materials, lithium cobalt oxide, LiFePO4, lithium manganese oxide, nickel-rich cathode, and solid electrolyte nanomaterials, are discussed and emphasized with the advantages and disadvantages, limitations, methods for improving and future development. The modification caused by nanotechnology truly can improve the performance of the lithium-ion battery. Lots of further researches that is changing the traditional materials into nanoscale or adding nanomaterials will be processed in the purpose of finding the most practical lithium-ion battery used in electric vehicles.

Silicic acid electrolyte additive reduces charge transfer impedance at sub-ambient temperature for lithium-ion rechargeable batteries

Vehicle electrification is a critical application of lithium-ion batteries (LIBs), and it is essential to develop LIBs that can operate at sub-ambient temperatures with satisfying performance. Conventional LIBs have performance deficits at low temperatures which hinder their use in extreme environments. One approach to address this problem is to rationally engineer the electrode/electrolyte interface with electrolyte additives to improve the electrochemical kinetics at sub-ambient temperatures. In this work, silicic acid (SiAc) is incorporated into standard LIB electrolyte as an additive to enhance the capacity and energy density of LIBs at temperatures down to −20 °C. Full-cell impedance analysis and X-ray photoelectron spectroscopy of cycled electrodes point towards an additive-induced change in surface chemistry which alters the charge transfer process. It is proposed that the SiAc additive participated in the formation of solid electrolyte interphase (SEI) and lowered the activation energy of the interface impedance, assisting lithium ion transport across the interface at lower temperatures.

Enhanced electrochemistry of AlPO4 nano-layer-wrapped LiMn2O4 cathode material for an aqueous rechargeable lithium-ion battery

Enhanced electrochemistry of AlPO4 nano-layer-wrapped LiMn2O4 cathode material for an aqueous rechargeable lithium-ion battery

Thermoelectric energy harvesting for wireless onboard rail condition monitoring

ABSTRACT A thermoelectric energy harvesting device is evaluated to power a bearing health monitoring system. Unlike wayside equipment, the new system is an onboard wireless solution utilizing accelerometer and temperature sensors to assess the bearing condition continuously. The harvesting system consists of two thermoelectric generator modules with aluminium heat sinks, a switching boost converter, a battery management circuit, and a lithium rechargeable battery. The performance of the harvester is validated on an AAR class bearing mounted on a laboratory tester, with load and speed simulating common freight routes of up to 896 miles. The energy harvested varies with operating conditions, and data is presented showing the effect of load and speed. Over a realistic route, the net energy harvested is more than double that needed to indefinitely power a Bluetooth Low Energy sensor. The critical design parameters are the ratio of open-circuit voltage to the temperature difference for the thermoelectric module, and the cold start voltage of the boost converter.

Dynamic phase evolution of MoS3 accompanied by organodiselenide mediation enables enhanced performance rechargeable lithium battery

Considerable efforts have been devoted to Li-S batteries, typically the soluble polysulfides shuttling effect. As a typical transition metal sulfide, MoS2 is a magic bullet for addressing the issues of Li-S batteries, drawing increasing attention. In this study, we introduce amorphous MoS3 as analogous sulfur cathode material and elucidate the dynamic phase evolution in the electrochemical reaction. The metallic 1T phase incorporated 2H phase MoS2 with sulfur vacancies (SVs-1T/2H-MoS2) decomposed from amorphous MoS3 achieves refined mixing with the "newborn" sulfur at the molecular level and supplies continuous conduction pathways and controllable physical confinement. Meanwhile, the insitu-generated SVs-1T/2H-MoS2 allows lithium intercalation in advance at high discharge voltage (≥1.8 V) and enables fast electron transfer. Moreover, aiming at the unbonded sulfur, diphenyl diselenide (PDSe), as a model redox mediator is applied, which can covalently bond sulfur atoms to form conversion-type organoselenosulfides, changing the original redox pathway of "newborn" sulfur in MoS3, and suppressing the polysulfides shuttling effect. It also significantly lowers the activation energy and thus accelerates the sulfur reduction kinetics. Thus, the insitu-formed intercalation-conversion hybrid electrode of SVs-1T/2H-MoS2 and organoselenosulfides realizes enhanced rate capability and superior cycling stability. This work provides a novel concept for designing high-energy-density electrode materials.

PEO/Li2ZrO3 composite electrolyte for solid-state rechargeable lithium battery

The organic/inorganic composite solid electrolytes (CSEs) for solid-state lithium batteries (LIBs) have attracted much attention for the possible advantages such as good interfacial compatibility, low cost, high efficiency and safety, etc. In this work, Li2ZrO3 inorganic Li-ion conductor is first time used as electrolyte filler for fabricating organic/inorganic CSE films. The CSE with 20 % (weight percentage) of Li2ZrO3 powder in polyethyleneoxide (PEO) exhibits high comprehensive performance with room-temperature conductivity of 6.76 × 10−6 S cm−1, electrochemical window of 4.2 V and ionic transference number of 0.20. The introduction of Li2ZrO3 obviously reduces the interfacial resistance between PEO and Li metal, and enhances the CSE stability by reducing the decomposition of LITFSI in CSE film. The assembled flexible Li/CSE/NCM811 solid-state LIBs deliver high rate capability and cycling stability. Li2ZrO3/PEO CSE is a promising electrolyte for flexible solid-state LIBs.

Recent Development in Topological Polymer Electrolytes for Rechargeable Lithium Batteries

Solid polymer electrolytes (SPEs) are still being considered as a candidate to replace liquid electrolytes for high-safety and flexible lithium batteries due to their superiorities including light-weight, good flexibility, and shape versatility. However, inefficient ion transportation of linear polymer electrolytes is still the biggest challenge. To improve ion transport capacity, developing novel polymer electrolytes are supposed to be an effective strategy. Nonlinear topological structures such as hyperbranched, star-shaped, comb-like, and brush-like types have highly branched features. Compared with linear polymer electrolytes, topological polymer electrolytes possess more functional groups, lower crystallization, glass transition temperature, and better solubility. Especially, a large number of functional groups are beneficial to dissociation of lithium salt for improving the ion conductivity. Furthermore, topological polymers have strong design ability to meet the requirements of comprehensive performances of SPEs. In this review, the recent development in topological polymer electrolytes is summarized and their design thought is analyzed. Outlooks are also provided for the development of future SPEs. It is expected that this review can raise a strong interest in the structural design of advanced polymer electrolyte, which can give inspirations for future research on novel SPEs and promote the development of next-generation high-safety flexible energy storage devices.

Nanoflowers-like LiTi2(PO4)3 on carbon nanotube fibers as novel binder-free anodes for high-performance fiber-shaped aqueous rechargeable lithium-ion batteries

NASICON-type LiTi2(PO4)3 (LTP) shows tremendous potential for applications in aqueous rechargeable lithium-ion batteries (ARLIBs) due to its three-dimensional open-framework and flat voltage platform. Unfortunately, conventional solid-phase reactions and high-temperature calcination methods are unable to meet the demand for self-standing electrodes for flexible wearable ARLIBs. Herein, we develop a simple and effective one-step solvothermal method to grow nanoflowers (NFs)-like LTP directly on carbon nanotube fibers (CNTFs) as binder-free anodes for fiber-shaped ARLIBs (FARLIBs) without additional high-temperature treatment. Benefitting from the robust adhesion of the active material to the substrate and binder-free feature, the prepared LTP NFs/CNTF anode provides a high reversible volume capacity of 85.2 mAh cm−3 at a current density of 0.4 A cm−3. The quasi-solid-state FARLIB is successfully assembled by binder-free cathode coupling with LiMn2O4 nanowall arrays directly grown on CNTF, achieving a high capacity of 58.3 mAh cm−3 at a current density of 0.4 A cm−3 and exhibiting an encouraging 92.3 mWh cm−3 maximum energy density. This work provides an effective strategy for the design of novel binder-free electrodes for next-generation wearable FARLIBs.

Semi-metallic bilayer borophene for lithium-ion batteries anode material: A first-principles study

Rechargeable lithium-ion batteries are increasingly in demand in the social sciences and the economy. The search for high-performance anode materials with high specific capacity and good structural reversibility is a major challenge. In this work, we employ the first-principles calculations to investigate the possibility of a semi-metallic bilayer boron structure as the anode material for lithium-ion batteries. The results show that the Li32B88 structure has a theoretical storage capacity of 902 mAh g−1 and the open circuit voltage is 0.18–1.17 V. The material delivers high structural stability with small volume change ratio of 0.77% during lithiation process. Meanwhile, the indirect diffusion barrier of lithium-ion is 0.47 eV, which shows a fast charge and discharge ability. The theoretical findings in this work suggest that the semi-metallic bilayer borophene is a potential anode material candidate for lithium-ion batteries.

Implementation and performance analysis of a novel sliding mode controller for bidirectional DC to DC converter in aircraft application

Purpose The purpose of this paper is to implement a closed loop regulated bidirectional DC to DC converter for an application in the electric power system of more electric aircraft. To provide a consistent power supply to all of the electronic loads in an aircraft at the desired voltage level, good efficiency and desired transient and steady-state response, a smart and affordable DC to DC converter architecture in closed loop mode is being designed and implemented. Design/methodology/approach The aircraft electric power system (EPS) uses a bidirectional half-bridge DC to DC converter to facilitate the electric power flow from the primary power source – an AC generator installed on the aircraft engine’s shaft – to the load as well as from the secondary power source – a lithium ion battery – to the load. Rechargeable lithium ion batteries are used because they allow the primary power source to continue recharging them whenever the aircraft engine is running smoothly and because, in the event that the aircraft engine becomes overloaded during takeoff or turbulence, the charged secondary power source can step in and supply the load. Findings A novel nonsingular terminal sliding mode voltage controller based on exponential reaching law is used to keep the load voltage constant under any of the aforementioned circumstances, and its performance is contrasted with a tuned PI controller on the basis of their respective transient and steady-state responses. The former gives a faster and better transient and steady-state response as compared to the latter. Originality/value This research gives a novel control scheme for incorporating an auxiliary power source, i.e. rechargeable battery, in more electric aircraft EPS. The battery is so implemented that it can get regeneratively charged when primary power supply is capable of handling an additional load, i.e. the battery. The charging and discharging of the battery is carried out in closed loop mode to ensure constant battery terminal voltage, constant battery current and constant load voltage as per the requirement. A novel sliding mode controller is used to improve transient and steady-state response of the system.

A Cellulose/Polyethylene Oxide Gel Polymer Electrolyte with Enhanced Mechanical Strength and High Ionic Conductivity for Lithium‐Ion Batteries

AbstractPolyethylene oxide (PEO) gel polymer electrolyte (GPE) is a promising electrolyte for rechargeable lithium‐ion batteries (LIBs). However, they still suffer from weak mechanical properties and low ionic conductivity. Herein, a novel hybrid GPE with enhanced mechanical properties and superior ionic conductivity is developed by introducing regenerated cellulose (RC) into PEO. Benefiting from the 3D porous interconnected network structure of cellulose aerogels, the obtained PEO‐RC GPEs exhibit improved mechanical strength (up to 40 MPa), increased electrolyte absorption ability, excellent ionic conductivity (4.34 × 10−3 S cm−1), and remarkable Li‐ion transfer number (0.60). As a result, a rechargeable LIB assembled with LiFePO4/GPEs/Li demonstrates a high initial discharge capacity of 149.3 mAh g−1 at 0.2 C and an impressive capacity of 141.3 mAh g−1 (94.6% capacity retention) after 100 cycles. This work provides a new route to the design and synthesis of novel GPEs toward next‐generation safe rechargeable LIBs.

Extremely-Long-Lifespan and Ultrahigh-Rate Li-Ion Batteries Using Conjugated Porous Triazine Polymers

As promising electrode materials, porous organic polymers (POPs) have been extensively investigated for rechargeable lithium-ion batteries (LIBs) owing to their significant surface area, tunable redox nature, open channels, and π-conjugated system. Herein, a nitrogen-rich two-dimensional triazine-containing microporous polymer (ACT) is designed and developed as an electrode material of a half-cell for rechargeable lithium-ion storage. The specialized porous and conjugated structure improves the effectiveness of electron transformation and physicochemical stability. Since it has a higher molecular weight, it performs well over exceptionally long cycling performance. According to the results, ACT-based LIBs display stable rate performance and may deliver a specific capacity of 247 mAh g–1 after more than 4000 cycles at 5 A g–1. Additionally, extensive experimental investigation and calculations are used to examine the lithium-ion diffusion mechanism of double active sites in the ACT. This work offers a possible strategy to design excellent organic materials of electrochemical performance for next-generation high-performance LIBs.

In-Situ Formed Phosphorus Modified Gel Polymer Electrolyte with Good Flame Retardancy and Cycling Stability for Rechargeable Lithium Batteries

The gel polymer electrolyte (GPE) is a promising substitution for traditional liquid electrolytes. However, GPE is still troubled mainly by its sluggish ionic conductivity and inferior interfacial compatibility with electrodes. Herein, a phosphorus-modified GPE was fabricated by in situ incorporation of black phosphorus (BP) nanosheets into a poly(methyl methacrylate) (PMMA) matrix during the self-polymerization of monomers. The developed GPE exhibited high ionic conductivity (1.083 mS·cm–1 at 30 °C), an enhanced Li+ transference number (0.43), and a wide electrochemical stability window (5.2 V vs Li+/Li), while good thermal stability and improved flame retardancy can also be achieved. Differential scanning calorimeter measurements confirmed that the crystallinity of the PMMA matrix was not changed as BP nanosheets were incorporated. Further investigation proved that BP nanosheets contained in PMMA segments effectively immobilized the anions to decrease the coordination number around Li+. As a result, Li+ ion transport through the GPE was facilitated, which promoted the uniform stripping/plating of lithium while cycling the lithium symmetry cell. Based on the phosphorus-modified GPE, the Li|LiFePO4 and Li|LiNi0.5Co0.2Mn0.3O2 batteries and graphite|LiFePO4 soft-package battery exhibited encouraging electrochemical performances and safety properties.

Pyramid-Patterned Germanium Composite Film Anode for Rechargeable Lithium-Ion Batteries Prepared Using a One-Step Physical Method

Using a top-down magnetron sputtering technique with a high deposition-rate, a one-step method for preparing germanium (Ge) hybrid film is presented. At present, graphite film is used as a current collector because it is flexible, self lubricating, and possesses a stress–strain-relieving property. In order to further suppress the volume changes of the Ge, a multilayered electrically conductive nickel film is deposited between multilayered Ge films. The cells are cycled at a current density of 200 mA g−1. An initial discharge and charge capacity of 1180.7 and 949.3 mAh g−1 are achieved by the prepared integrated pyramid patterned Ge composite film anode, respectively. The average capacity was maintained at 580 mAh g−1 after 280 cycles. In the rate capability measurement, the Ge composite demonstrated a reversible capacity of 1163.1 mAh g−1. It is easily made using magnetron sputtering, which is widely accepted in the industry. A physical approach to increase pure Ge’s specific capacity and its cycle life for LIBs is demonstrated in this work.

Mechanism, quantitative characterization, and inhibition of corrosion in lithium batteries

Rechargeable lithium batteries with long calendar life are pivotal in the pursuit of non-fossil and wireless society as energy storage devices. However, corrosion has severely plagued the calendar life of lithium batteries. The corrosion in batteries mainly occurs between electrode materials and electrolytes, which results in constant consumption of active materials and electrolytes and finally premature failure of batteries. Therefore, understanding the mechanism of corrosion and developing strategies to inhibit corrosion are imperative for lithium batteries with long calendar life. In this review, different types of corrosion in batteries are summarized and the corresponding corrosion mechanisms are firstly clarified. Secondly, quantitative studies of the loss of lithium in corrosion are reviewed for an in-depth understanding of the mechanism. Thirdly, the recent progress in inhibiting corrosion is demonstrated. Finally, perspectives to further investigate corrosion mechanism and inhibit corrosion are put forward to promote the development of stable lithium batteries.