Materials For Lithium-ion Batteries Research Articles

A K2C2O4/nano-CaCO3 dual-templated method to prepare rich nitrogen-doped hierarchical porous carbon with excellent lithium storage performance

Three-dimensional interconnected porous carbon with diverse guest element doping is considered one of the most promising anode materials in lithium-ion batteries (LIBs) owing to their large lithium storage capacity and the acceleration effects on the electrochemical kinetics. However, the regulation of desirable pore structure and guest element amount and species for high energy density and stable cycling performance is still challenging. Herein, sucrose-based hierarchical N-doped porous carbon (SHC-750) is prepared via a facile one-step carbonization/activation process at 750 °C for 1 h. The K2C2O4 and nano-CaCO3 are employed as the dual activating-agent/template, and the urea is used as an N source. Benefiting from the hierarchical porous structure, abundant defects, and high amount of N/O-containing functional groups with a multi-chemical state, SHC-750 delivers an excellent reversible specific capacity (1051.2 mAh/g at 0.1 A/g and) and great cycling stability. Moreover, SHC-750 exhibits fast lithium ions diffusion kinetics, which is attributed to the special ordered and hierarchical pore structure. This work provides a new pathway for the preparation and application of 3D interconnected porous carbon materials in the field of electrodes.

Cu@MOF based composite materials: High performance anode electrodes for lithium-ion and sodium-ion batteries

In order to satisfy the increasing demand for energy, it is essential to improve the efficiency of lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) batteries. Metal selenides (MSes) have a high theoretical specific capacity, can be designed in a variety of ways, conduct electricity well, can change morphology easily, and have a multi-electron reaction mechanism. These characteristics make them very competitive as anode materials for LIBs and SIBs. Herein, we synthesise Cu@MOF and Cu@NH2-MOF as the precursor to prepare Cu1.95Se embedded into porous carbon matrix (Cu1.95Se@PC) and porous-N-doped carbon matrix (Cu1.95Se@NPC) via pyrolysis process of Cu@MOF and Cu@NH2-MOF, respectively. Cu1.95Se@PC and Cu1.95Se@NPC electrodes for half-cell LIBs and SIBs exhibit a high reversible capacity of 313.1, 480.9 (for LIBs), 216.3 and 303.8 (for SIBs) mAhg−1after 1000 cycles at 2 A g−1, respectively. We assess the electrochemical performance of the Cu1.95Se@PC and Cu1.95Se@NPC anodes by integrating them with commercially available LiFePO4 (LFP) into full-cell LIBs. The LFP//Cu1.95Se@PC and LFP//Cu1.95Se@NPC full-cells have discharge capacities of approximately 330 and 293 mAh g−1 at 0.3 A g−1 at the initial cycle. In order to explore the sodium storage mechanism of the Cu1.95Se composites, we conducted an in situ XRD test during the first charge/discharge cycle, considering their favourable cycling and rate performance. Our work provides a promising anode electrode material for both half-cell LIBs and SIBs with high volume utilization and superior electrochemical performances.

A novel coating layer of mesoporous silica on LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode material for advanced lithium-ion batteries

NCM811 cathode material has many commercial features such as reasonable price, environmental friendliness and high specific capacity, yet it suffers from capacity attenuation during cycling. Silica (SiO2) coating strategy is a valid approach to enhance the capacity retention of NCM811. However, the insulating nature of coating layer reduces the electrochemical performance. Herein, a novel route is developed to alleviate this issue by using a mesoporous layer instead of bulk layer. The mesoporous layer is prepared by condensing a mixture of fine templates (Cetyltrimethylammonium bromide, CTAB) and tetraethyl orthosilicate (TEOS) on NCM811 particles and calcining them to remove templates. The structure, morphology, surface chemical state and electrochemical performance of samples are widely investigated. Results indicate that the mesoporous layer (SiO2-20 wt.% of CTAB) exhibits discharge capacities of 210 and 138 mAh g−1 at 0.1 C and 5C over 2.7–4.3 V, while those of bulk SiO2 coated sample are only 189 and 98 mAh g−1, respectively. This mesoporous layer offers a capacity maintenance of 87.3% after 100 cycles, compared to only 69.3% for pure NCM811 at 1 C. The mesoporous layer not only improves the discharge capacity of NCM811 but also reduces its capacity fading.

Carbon-coated MoS2/Mxene hybrids for enhanced Li-ions storage performance

MoS2/Mxene/C was synthesized by a facile hydrothermal method. The electrochemical measurements revealed that, in comparison to MoS2/Mxene, the MoS2/Mxene/C composite exhibited an initial charge/discharge capacity of 1440 mAh/g and 2107 mAh/g at a current density of 0.1 A/g. Furthermore, it maintained a specific capacity of 688.2 mAh/g after undergoing 200 cycles at a higher current density of 1 A/g, thereby demonstrating remarkable superior specific capacity and cycling stability. Consequently, MoS2/Mxene/C is anticipated to serve as a high-performance anode material for lithium-ion batteries (LIBs).

Hierarchical porous silicon oxycarbide as a stable anode material for lithium-ion batteries

Hierarchical porous silicon oxycarbide as a stable anode material for lithium-ion batteries

The Effect of Nickel Addition on α-Fe2O3 Synthesis Using NaOH and Application as Lithium-Ion Battery Anode Material

Research has been conducted in the pursuit of developing the performance of batteries. The increasing demand for electronic devices and electric vehicles has driven the development of high-performance lithium-ion batteries (LIBs). Among the various anode materials, α-Fe2O3 has attracted significant attention due to its high theoretical specific capacity of 1007 mAh/g. However, its low conductivity and poor rate capability limit its practical application. To address these issues, this study investigates the addition of nickel (Ni) into α-Fe2O3 through a co-precipitation method. The synthesized materials were characterized using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Scanning Electron Microscopy with Energy-Dispersive X-ray spectroscopy (SEM-EDX). The electrochemical performance was evaluated using an LCR meter and charge-discharge cycling. The results showed the addition of Ni improved the conductivity of the α-Fe2O3 material. The optimal Ni content was found as much as 18×10-4 mol which exhibits the highest conductivity and specific capacity. The synthesized α-Fe1.965Ni0.035O3 material demonstrated a specific charging capacity of 1.8433 mAh/g and a specific discharging capacity of 1.8388 mAh/g. These findings suggest that Ni-doped α-Fe2O3 has the potential to be a promising anode material for high-performance lithium-ion batteries (LIBs).

Revealing the Dual Role of Ammonia in the Hydroxide Co-precipitation Synthesis of Cobalt-free Nickel-rich LiNi0.9Mn0.05Al0.05O2 (NMA955) Cathode Materials for Lithium-ion Batteries.

Nickel-rich cobalt-free LiNi0.9Mn0.05Al0.05O2 (NMA955) is considered a promising cathode material to address the scarcity and soaring cost of cobalt. Particle size and elemental composition significantly impact the electrochemical performance of NMA955 cathodes. However, differences in precipitation rates among metal ions coveys a challenge in obtaining cathode materials with the desired particle size and composition via hydroxide co-precipitation synthesis. Utilizing complexing agents like ammonia offers an effective strategy to tackle these issues. Here, we investigate the optimal ammonia concentration to achieve moderate particle size and precise material composition. Although ammonia only forms complex coordination with transition metals, its concentration also affects the final product's precipitation and composition, including aluminum. This study shows that ammonia serves a dual function in NMA synthesis via hydroxide co-precipitation, i.e., regulating particle size and adjusting elemental composition. It was found that an ammonia concentration of 1.2 M achieved optimal particle size and composition, resulting in superior electrochemical performance. NMA955 synthesized in 1.2 M ammonia demonstrated a high specific capacity of 188.12 mAh g-1 at 0.1C, retained 71.16% of its capacity after 200 cycles at 0.2C, and delivered 110.30 mAh g-1 at 5C. These results suggest tuning ammonia concentration is crucial for producing high-performance cathode materials.

Leaching Kinetics of Valuable Metals from Calcined Material of Spent Lithium-Ion Batteries

Leaching Kinetics of Valuable Metals from Calcined Material of Spent Lithium-Ion Batteries

Entropic Design of Anionic Site to Improve Anionic Redox Stability in Lithium-Rich Cathode.

Cobalt-free manganese-rich layered oxide is considered one of the most promising cathode materials for next-generation lithium-ion batteries due to its high capacity and low cost. However, irreversible anionic redox (OAR) leads to serious failure problems and hinders its wide application. To solve the above problems, the entropy design strategy of anionic sites is proposed, which is more direct and relevant to the regulation of the OAR process compared to the traditional entropy design of TM sites. The entropic design improves the structural diversity and long-range disorder of the material, which effectively inhibits oxygen release and drastic structural strain, and alleviates structural degradation. After 400 cycles at 1C, the capacity and voltage decay per cycle are only 0.092 mAhg-1 and 1.36mV, respectively. The long cycle test (10C and 1000 cycles) at high current shows that the voltage and capacity decay are only 0.04 mAhg-1 and 0.66mV per cycle, respectively. Meanwhile, the rate performance at 10C reaches 175 mAhg-1. The charge compensation regulation and performance enhancement mechanism are investigated by systematic in-situ/ex-situ characterization and theoretical calculation. This research provides new ideas for the design of lithium-rich cathodes with stable OAR and high structural adaptability.

Chromium Oxide Nanoparticles Anchored in Hydrogel-Derived Three-Dimensional N-Doped Porous Carbon Anode Materials as Lithium-Ion Batteries.

Transition metal oxides (TMOs) have been identified as the most promising anode materials for lithium-ion batteries (LIBs). However, these materials tend to undergo volumetric expansion during battery operation, which disrupts their internal structure and ultimately leads to a degradation of battery performance. Cr2O3/N-doped porous carbon (Cr2O3@NC) composites were successfully synthesized through high-temperature calcination using Cr2O3-containing hydrogels as precursors. The results show that the carbon material not only improves the electron transfer ability of Cr2O3 but also effectively prevents its agglomeration. The Cr2O3@CN composite as a novel anode material for LIBs exhibits a reversible capacity of 936 mAh g-1 after 200 cycles at a current density of 1 A g-1, showcasing excellent cycling and structural stability during cycling. Scanning electron microscopy analysis reveals that the Cr2O3@NC composite remains structurally intact throughout cycling. The innovative approach proposed in this study provides a new direction for the advancement of electrode materials for energy storage technologies.

Liquid metal-enhanced MoS2 nanocomposite for self-healing colloidal anodes in lithium-ion batteries

Energy storage is pivotal in addressing global energy challenges, with lithium-ion batteries (LIBs) at the forefront. However, their longevity is often limited by anode material degradation. Here, we introduce a novel LM/AgNWs@MoS2 nanocomposite anode material, synthesized via a one-step hydrothermal method, which integrates liquid metal's fluidity with silver nanowires' conductivity and MoS2's rapid lithium-ion diffusion. This composite demonstrates exceptional cycling stability, maintaining 468 mA h g−1 over 2000 cycles at 1 A g−1, and self-heals electrode cracks, offering a significant advancement for LIBs durability and safety. The LM/AgNWs@MoS2 nanocomposite addresses the critical need for durable, self-healing anode materials in LIBs, pushing forward the development of next-generation energy storage solutions.

Half‐Heusler Alloy CoMnZ (Z = Sb/Sn): Electrode Material for Lithium‐Ion Batteries

ABSTRACTHeusler alloys (HAs) are a well‐known family of compounds generating promising interest due to their robust structure, ease of tailoring their unique properties, and potential applications. The investigations in the direction of the electrochemical performance of these materials as electrodes for rechargeable lithium‐ion batteries (LIBs) have been established theoretically and experimentally. Alloying of alkali metal ions into half‐HAs unit cells can be another route to improve LIBs performance. This work presents our investigations on thermodynamically stable half‐HAs CoMnZ (Z: Sb/Sn) as electrode materials for rechargeable LIBs using the first‐principle calculations based on the density functional theory. The negative formation energies validate the thermodynamic stability of the alloys considered in this study. With increasing Li doping, a structural change from cubic to tetragonal and orthorhombic phase is observed in the host structure, and upon full lithiation (LiMnZ), a cubic structure is attained. The band structure calculations of the host structure and its lithiated phase indicate a metallic nature in these alloys. The calculations are also performed to investigate the structural stability of parent alloys and corresponding lithiated phases. We calculated a storage capacity of around 14.5 Ah/kg for 0.125 atomic fraction of Li atoms, which is increased by nearly 10 times upon full lithiation. A maximum open circuit voltage of around 9.8 V is calculated for Li0.125Co0.875MnSb and CoLi0.125Mn0.875Sb. Thus, all these remarkable results suggest that these intermetallic compounds have a strong potential as the cathode material for LIBs with a robust life and a large capacity.

Waxberry-like TiO2 with Synergistic Surface Modification of Pyrolytic Carbon Coating and Carbon Nanotubes as an Anode for Li-Ion Battery.

Titanium dioxide (TiO2) as an anode material for lithium-ion batteries (LIBs) has the advantages of tiny volume expansion, high operating voltage, and outstanding safety performance. However, due to the low conductivity of TiO2 and the slow diffusion rate of lithium ions (Li+), it is limited in the application of LIBs. Therefore, waxberry-like TiO2 comodified by pyrolytic carbon coating and carbon nanotubes was prepared in this work. The waxberry-like TiO2 with nanorods on its surface shortens the diffusion distance of Li+. Carbon nanotubes and waxberry-like TiO2 are tightly combined through electrostatic assembly and form a cross-linked conductive network to provide more electron transmission paths. A thin layer of pyrolytic carbon wraps carbon nanotubes and waxberry-like TiO2, which enhance the conductivity of the composites and ensure the structural integrity of the materials throughout the cycling process. The experimental data revealed that the discharge-specific capacity of TiO2@CNT@C is 170.5 mAh g-1 after 3000 cycles at a large current density of 5 A g-1, and the discharge-specific capacity is still 143 mAh g-1 at the superhigh rate of 10 A g-1, which provides excellent rate performance and cyclic stability. The efficient dual-carbon modification strategy could potentially be extended to other materials.

Effective Stabilization of Organic Cathodes Through Formation of a Protective Solid Electrolyte Interface Layer via Reduction.

2,5-Dihydroxy-1,4-benzoquinone (DHBQ) is a promising cathode material, but its high solubility in electrolytes leads to rapid capacity degradation. This study investigates the dilithium salt of DHBQ, Li2DHBQ, as a cathode material for lithium-ion batteries (LIBs). Despite minimal solubility, Li2DHBQ cathodes suffer rapid capacity decay due to severe morphological damage within the voltage range of 1.5-3.0 V. To stabilize morphology, we promoted a protective solid electrolyte interphase (SEI) layer on Li2DHBQ particles by lowering the discharge cutoff voltage. Cycling the battery with a 0.5 V discharge cutoff voltage achieved an optimal SEI layer, significantly improving Li2DHBQ's morphological stability. Consequently, the battery maintained 170 mAh g-1 with a low decay rate of 0.16% within a voltage range of 0.5-3.0 V after 200 cycles at 500 mA g-1. Furthermore, initial cycling at a 0.5 V discharge cutoff for 20 cycles to form an SEI layer, followed by cycling at a normal 1.5 V discharge cutoff, retained a higher capacity of 187 mAh g⁻¹ after 200 cycles. This study demonstrates the effectiveness of forming a cathode SEI layer at low discharge voltages as a new approach to stabilizing organic cathode materials.

Research Progress on the Safety of LIBs Separators

Over the years, the electrification of transport has forced improvements in energy storage batteries. Lithium-ion batteries (LIBs) are widely used in aerospace, smart devices, electronic communications, and transport because of their high capacity, good cyclability, and environmental friendliness. However, battery safety is a massive issue in people's daily lives. LIBs occasionally suffer from spontaneous combustion and explosion. This is mainly caused by short circuits within the battery. The diaphragm, as the material separating the positive and negative electrodes, prevents the positive and negative electrodes from coming into direct contact, thus avoiding short circuits. The performance of the diaphragm determines the safety of LIBs. Therefore, this paper first introduces the causes of the thermal runaway of lithium-ion batteries and its relationship with diaphragms. Then, this paper presents the essential characteristics and types of high-safety diaphragms. Finally, this paper also summarises the physical and chemical modification methods of diaphragm materials in LIBs. This will help improve the safety of lithium-ion batteries, increase the electrification of transportation, and eliminate concerns about using LIBs.

Development of Low Temperature Lithium Ion Batteries

This article briefly introduces the history of the birth of lithium-ion batteries and discusses the necessity of studying how to make lithium-ion batteries work properly under low-temperature conditions. It also introduces the development of ternary materials, a common material for lithium-ion batteries, in the past two years, as well as the working conditions and performance advantages and disadvantages of ternary materials and another commonly used positive electrode material, lithium iron phosphate, in different environments. Finally, a comprehensive overview of the development path of lithium-ion positive electrode materials under low-temperature conditions is given.

Advances in Lithium Iron Phosphate Cathode Materials for Lithium-Ion Batteries

LiFePO4 has become very prospective cathode materials for lithium-ion batteries because of its stable charge/discharge performance, high specific capacity and high safety. At present, the main challenges facing lithium iron phosphate cathode materials is the poor conductivity and low energy density, which urgently need to be optimized. This paper summarizes the mainstream modification strategies for lithium iron phosphate cathode materials by exploring the relevant literature in recent years. In detail, the crystal structure and the reaction mechanism of LiFePO4 cathode materials during the charging and discharging process were investigated and reviewed. Based on the disadvantages of LiFePO4 cathode, the three targeted modification methods including carbon coating, metal ion doping and nanosizing are also analyzed. By strengthening the research on the above improvement strategies, the ideal LiFePO4 with excellent performance is expected.

Molten salt assisted synthesis of Si/C nanocomposite derived from palygorskite and sodium alginate for electrochemical lithium storage.

Silicon/carbon (Si/C) nanocomposites are considered as one of the most promising anode materials for lithium-ion batteries due to their high capacity and suitable lithiation potential. However, the complex and time-consuming preparation processes of silicon-based nanocomposites and the unexpected silicon carbide generated during high treatment make it difficult to achieve high-performance Si/C nanocomposites for practical applications. Herein, a silicon/carbon nanocomposite is successfully prepared through a facile and eco-friendly molten salt assisted precarbonization-reduction method using palygorskite (PAL) and sodium alginate as raw materials. Based on physical characterizations, it is demonstrated that the sodium alginate plays a key role in the successful preparation of Si/C nanocomposite, which not only boosts uniform embedding of PAL nanoparticles in the carbon matrix but also releases molten sodium salt to suppress the formation of unexpected SiC. When used as an alternative anode material for lithium-ion battery applications, the as-obtained Si/C composite delivers a high reversible specific capacity of 1362.7 mA h g-1 with an initial Coulombic efficiency of 70.3% at a current density of 200 mA g-1 and excellent long-term cycling stability. The findings here provide a facile and eco-friendly molten salt assisted precarbonization-reduction method for high-performance silicon/carbon anode materials.

Thermal characteristics of LiMnxFe1-xPO4 (x = 0, 0.6) cathode materials for safe lithium-ion batteries

Lithium-ion batteries have recently gained attention as energy storage devices due to their high energy densities and various applications. Layered Ni-Mn-Co-based cathode materials are widely used for their high energy density; however, their high cost necessitates the exploration of alternatives. Consequently, olivine-type LiMnxFe1-xPO4 materials are gaining popularity and are being increasingly adopted. While the synthesis methods and electrochemical properties of these materials have been extensively studied, thermal analyses remain limited. In this study, we investigated the thermal properties of olivine-type LiMnxFe1-xPO4 by combining thermal analysis, structural analysis, and computational calculations to evaluate the safety of lithium-ion batteries. Our results show that the formation energy of LiMn0.6Fe0.4PO4 is more stable than that of LiFePO4. As temperature increases, LiFePO4 decomposes at 350 °C, whereas LiMn0.6Fe0.4PO4 begins to decompose at 450 °C. The P-O bond plays a crucial role in the thermal stability of these materials; as the temperature rises, the thermal stability of the PO4 group diminishes, leading to structural decomposition. To enhance thermal stability, it is recommended to experiment with doping small amounts of various elements at the P site. This paper provides valuable insights for the design and development of thermally stable olivine-structured cathodes for lithium-ion batteries.

Layered/Olivine Composite Structure-Induced Stable Gradient Interfacial Chemistry toward High-Temperature Lithium-Ion Batteries.

The state-of-the-art layered oxide as the cathode material for lithium-ion batteries has attracted wide attention; however, harsh operations of high-energy and high-safety energy-storage technology at high temperature is challenging owing to the aggravated structural instability and parasitic reactions at the cathodes. Herein, the layered/olivine composite structure architecture is designed at the grain surface to govern constant electrochemistry in a harsh environment, and a gradient LiF interlayer is developed onto the cathodes to suppress the interfacial degradation. By a combination of interfacial-sensitive characterizations and theoretical analysis at the cathode/interface, the formation mechanism of this special interphase induced by the composite structure cathode is revealed. The composite structure cathode could deliver an excellent high-temperature cycling stability with 90.8% retention for 300 cycles in the half cell and 95.6% retention for 1000 cycles in the pouch cell and simultaneously enhances ∼51% of the thermal stability, which broadens the approaches for developing high-stable cathodes that work in extreme environments.