Anode For Lithium-ion Batteries Research Articles

Interfacial carbon tailoring of porous SiOx/carbon nanotube hybrids towards high-rate lithium storage

Fast charging Lithium-ion batteries (LIBs) is highly required with the massive development of the electric vehicle market. Integrating silicon with carbon nanotubes (CNTs) has shown great promise for constructing high-rate anodes of LIBs. However, current reported silicon axially coated CNTs electrodes fail to provide a robust conductive connection within the interfacial layer, causing unsatisfactory rate performance. In this paper, a series of novel coaxial hollow nanocables of SiOx/C coated CNTs composite were presented based on a simple sol–gel method and subsequent calcination. Due to the uniform composition of carbon and SiOx at sub-nanometer scale in the coating layer, a strong 3D conductive network is formed between the internal carbon nanotubes and the neighboring electrode particles. When utilized as LIBs anodes, such novel hybrids manifest high reversible capacity (511 mA h g−1 remained after 500 cycles at 0.5 A g−1), high-rate capability (232 mA h g−1 at 5 A g−1) and ultra-long high-current cycling stability (396 mA h g−1 remained after 1000 cycles at 1.0 A g−1). The structural characterization and electrochemical dynamics analysis show that the synergistic effect of abundant mesoporous channels in the coating layer and strong carbon 3D conductive network makes this unique composite structure exhibit excellent electrochemical performance. This work sheds novel light on the wisely design of advanced Si-based anodes with enhanced fast charging performance.

Unlocking High-Current Performance in Silicon Anode: Synergistic Phosphorus Doping and Nitrogen-Doped Carbon Encapsulation to Enhance Lithium Diffusivity.

The silicon (Si) offers enormous theoretical capacity as a lithium-ion battery (LIB) anode. However, the low charge mobility in Si particles hinders its application for high current loading. In this study, ball-milled phosphorus-doped Si nanoparticles encapsulated with nitrogen-doped carbon (P-Si@N-C) are employed as an anode for LIBs. P-doped Si nanoparticles are first obtained via ball-milling and calcination of Si with phosphoric acid. N-doped carbon encapsulation is then introduced via carbonization of the surfactant-assisted polymerization of pyrrole monomer on P-doped Si. While P dopant is required to support the stability at high current density, the encapsulation of Si particles with N-doped carbon is influential in enhancing the overall Li+ diffusivity of the Si anode. The combined approaches improve the anode's Li+ diffusivity up to tenfold compared to the untreated anode. It leads to exceptional anode stability at a high current, retaining 87 % of its initial capacity under a large current rate of 4000 mA g-1. The full-cell comprising P-Si@N-C anode and LiFePO4 cathode demonstrates 94 % capacity retention of its initial capacity after 100 cycles at 1 C. This study explores the effective strategies to improve Li+ diffusivity for high-rate Si-based anode.

Selective construction of amorphous/crystalline heterostructure high entropy oxide for Li-ion batteries

High entropy oxides (HEO) are widely used as anode for lithium-ion batteries due to their exceptional chemical stability and mechanical strength. However, HEO encounters challenges such as low initial coulomb efficiency (ICE) and poor capacity. To address these issues, a simple mechanochemical method is employed to selectively amorphized and densely embed LiF within the HEO matrix. Taking advantage of the differing chemical properties of LiF and HEO, the transformation of LiF’s crystal structure not only overcomes its poor ionic conductivity but also successfully constructs an amorphous LiF/crystalline HEO heterostructure, which also improves the transport capacity of lithium ions. Additionally, the presence of abundant defects (e.g., oxygen vacancies, dislocations, and stacking faults) boosts the material's lithium transport and storage capacity. Furthermore, LiF facilitates the formation of a stable solid electrolyte interface (SEI) film on the HEO surface, preventing the corrosion of active materials and minimizing side reactions, effectively improving the ICE. The as-prepared LiF/HEO-48 demonstrates a superior initial capacity of 1632.9/1158.5 mAh g−1, along with an ICE of 70.9%. It maintains a high reversible capacity of 552.2 mAh g−1 after 1000 cycles at 0.5 A g−1, and even after 400 cycles at 2 A g−1, it retains 99.4% of its capacity. This study may open up new ways to selectively construct amorphous/heterostructures to improve the ICE and capacity of lithium-ion anodes.

Enhancing air stability of LiMg alloy anode through Yb segregation at grain boundaries

Owing to the ultrahigh theoretical specific capacity and the most negative electrochemical potential, lithium metal has become the most promising lithium battery anode material. However, it is highly susceptible to oxidation during industrial production and storage processes. The polycrystal surface of the lithium metal anode serves as the site for oxidation reaction, and the reaction pathway is inevitably influenced by the microstructure of the anode surface. especially the grain boundaries, which with higher activity than a crystallographic plane, leading to intercrystalline oxidation reactions. Within the LiMg@Yb alloy system, ytterbium (Yb) segregated at the grain boundaries, leading to a reduction in intercrystalline energy as predicted by Density Functional Theory (DFT) calculations. Thus, the LiMg@Yb alloy can effectively suppress intercrystalline oxidation reactions and enhance air stability. More impressively, even exposed to ambient air for 0.5 h, the LiMg@Yb-0.5||LFP full cell exhibited a higher capacity retention rate (80.7%) than the bare Li-0.5||LFP (35.9%) after 100 cycles. This work presents a new approach for enhancing air stability by inhibiting intercrystalline oxidation reactions between anodes and air.

Mechanically robust and conductive Ti5Te4/P@C composite materials as promising lithium-ion battery anodes

An urgent need has emerged to develop lithium-ion battery anodes that exhibit high reversible capacity and rate performance surpassing carbonaceous materials. Si-based composites have been investigated extensively. However, in this study, we explored another potential alloy anode consisting of Te and phosphorus without Si. Herein, we present a novel composite material, Ti5Te4/P@C, as an anode for lithium-ion batteries (LIBs). Tellurium, which exhibits good electrical conductivity and high volumetric capacity, and red phosphorus, which exhibits high theoretical capacity, were selected as potential anode materials. To overcome the common drawbacks of the two materials, including the vigorous expansion of volume, electrochemically inactive materials, such as titanium and carbon, were introduced as matrix buffers. Te, Ti, red phosphorus, and C were synthesized using a three-step high energy ball milling (HEBM) technique, that is, stepwise synthesis of (1) Ti and Te, (2) red phosphorus, and (3) carbon. The developed Ti5Te4/P@C composites revealed that the introduction of red P led to the generation of additional pure Te in the Ti5Te4/P@C composites, which was owing to the different binding interactions between Ti, Te, and red P, as confirmed by DFT calculations. Among the developed Ti5Te4/P@C anodes, Ti5Te4/P(30 wt%)@C exhibited outstanding cyclability and high rate performance (440 mAh g−1 at 300 mA g−1 after 500 cycles). To confirm the electrochemical responses and Li+ ion diffusion mechanisms, CV and GITT analyses were performed. Based on the electrochemical characteristics, the superior electrochemical performance of the Ti5Te4/P@C anodes can be ascribed to the well-defined composite structure, including the high electrical conductivity of Te, high theoretical capacity of red P, and effective buffering agents of Ti as a mechanical supporter and conductive C, which enable a pseudocapacitive response, providing better reversibility. Therefore, the Ti5Te4/P@C composite materials are viable anodes for high-performance LIBs.

3D-structured Co9S8@NSG prepared using deep eutectic solvents as high-performance anode material of lithium-ion batteries

Transition metal sulfides (TMSs) are ideal materials for replacing graphite anodes in lithium-ion batteries (LIBs). However, their low conductivities and large volume changes during charge/discharge cycling greatly limit their applications. Herein, a new method for co-doping nitrogen and sulfur in 3D graphene via a one-step method in deep eutectic solvents (DESs) was developed to prepare Co9S8@NSG composites, enhancing the storage performance of LIBs. The obtained Co9S8@NSG nanosheets exhibited excellent lithium-ion storage performance as anode materials. In the first cycle, the electrode material possessed high specific capacity (1647.5 mAh·g−1 at a current density of 2 a·g−1). After 250 cycles, the reversible capacity was still maintained at 516 mAh·g−1. The electrode material also displayed good cycling stability with specific capacity reaching 710 mAh·g−1 after 700 cycles at a current density of 0.5 a·g−1. In sum, the developed route for the synthesis of heteroatom-doped nanocomposites looks promising for modification of sulfide materials as excellent-performance LIBs.

A flexible plane-wire MoO2-anchored carbon nanofiber matrix as freestanding anodes for lithium storage with enhanced cyclability

Inspired by beds of silkworm cocoon, a flexible ″plane-wire″ MoO2-anchored carbon nanofiber matrix has been successfully prepared through electrospinning and subsequent annealing processes. It delivers an initial discharge capacity of 877 mAh g−1 at 200 mA g−1 with a high initial coulombic efficiency of 84.7 % and showcases a high reversible specific capacity of 743 mAh g−1 in the second cycle when employed as free-standing anodes for lithium batteries. It also exhibits good rate performance and superb cyclability, which delivering a specific capacity of 364 mAh g−1 at a high current density of 2 A g−1 and maintains a notable specific capacity of 674 mAh g−1 even after 2000 cycles. It is found that, the carbon nanofiber matrix serves as a robust electronic conductive network to reduce the charge transfer resistance and promote the transportation of Li+, and provides excellent support to buffer volume changes of the MoO2, resulting in enhanced rate performance and cyclability. Moreover, these electrodes are designed to be free-standing, which can improve the flexibility of the electrode and initial coulombic efficiency. It is believed that the as-prepared ″plane-wire″ MoO2-anchored carbon nanofiber matrix is a promising anode material for high-performance LIBs.

Boron-doped three-dimensional porous carbon framework/carbon shell encapsulated silicon composites for high-performance lithium-ion battery anodes

Deleterious volumetric expansion and poor electrical conductivity seriously hinder the application of Si-based anode materials in lithium-ion batteries (LIBs). Herein, boron-doped three-dimensional (3D) porous carbon framework/carbon shell encapsulated silicon (B-3DCF/Si@C) hybrid composites are successfully prepared by two coating and thermal treatment processes. The presence of 3D porous carbon skeleton and carbon shell effectively improves the mechanical properties of the B-3DCF/Si@C electrode during the cycling process, ensures the stability of the electrical contacts of the silicon particles and stabilizes the solid electrolyte interface (SEI) layer, thus enhancing the electronic conductivity and ion migration efficiency of the anode. The developed B-3DCF/Si@C anode has a high reversible capacity, excellent cycling stability and outstanding rate performance. A reversible capacity of 1288.5 mAh/g is maintained after 600 cycles at a current density of 400 mA g−1. The improved electrochemical performance is demonstrated in a full cell using a LiFePO4-based cathode. This study presents a novel approach that not only mitigates the large volume expansion effects in LIB anode materials, but also provides a reference model for the preparation of porous composites with various functionalities.

Three-dimensional porous polyimide anode for high-rate lithium ion batteries

Polymeric electrode materials are widely used in many applications but still suffer from poor electrical conductivity and slow transport kinetics, especially poor performance at high current densities. Herein, a polyimide electrode structure with 3D-ordered interconnected gradient pores was developed to improve the lithium-ion transport efficiency. The homogeneous mixed PMTA-PMMA composite was prepared by a simple one-pot method, followed by removal of PMMA (polymethyl methacrylate) spherical porogenic agent during the synthesis of polyimide material at high temperatures to form a low curvature gradient-pore structure. The large pores in the electrode enhanced the ion transport ability and improved the electrolyte infiltration rate, while the small pores improved the active specific surface area and guided the deposition of lithium ions. As a result, a high specific capacity reaching 907 mAh/g was maintained even after 1000 cycles at 5 A/g, a value about 3-fold that of un-pored electrode materials. The experimental studies and DFT calculations were used to develop a 24Li storage mechanism of PMTA, and the active electrode material was fully electrochemically activated by the constructed three-dimensional porous electrode structure. Overall, the proposed porous material with a high active area and porosity looks potential for use as an ultra-fast charging and discharging electrode of lithium-ion batteries with high specific capacity and excellent cycling performance.

High performance carboxymethyl cellulose- polyethylene oxide polymer binder for black phosphorus anode in lithium-ion batteries

Black phosphorus (BP) is regarded as a promising anode material due to its high theoretical specific capacity and fast charging safety. However, the problems of huge volume expansion and moderate electrical conductivity may restrict its performance. In this work, we present a novel 3D network binary polymer binder synthesized from carboxymethyl cellulose (CMC) and polyethylene oxide (PEO) for adapt to lithium-ion batteries of BP and graphite (G) composite anode (BP-G). There are the following characteristics of the binder: CMC and PEO are crosslinked through intermolecular forces; while CMC and PEO are connected to BP through strong intermolecular forces, respectively; BP and graphite are connected through PC and POC bonds to form composite anode. So as to form a sturdy structure and effectively accommodate the volume expansion of BP during charging-discharging processes, while avoiding loss of electrical contact between electrode components. Accordingly, the lithium-ion battery shown an excellent electrochemical performance, such as a high initial discharge capacity of 1602 mA h g−1 at 0.5 A/g.

Electrodeposition of Silicon Fibers from KI–KF–KCl–K2SiF6 Melt and Their Electrochemical Performance during Lithiation/Delithiation

The possibility of using Si-based anodes in lithium-ion batteries is actively investigated due to the increased lithium capacity of silicon. The paper reports the preparation of submicron silicon fibers on glassy carbon in the KI–KF–KCl–K2SiF6 melt at 720 °C. For this purpose, the parameters of silicon electrodeposition in the form of fibers were determined using cyclic voltammetry, and experimental samples of ordered silicon fibers with an average diameter from 0.1 to 0.3 μm were obtained under galvanostatic electrolysis conditions. Using the obtained silicon fibers, anode half-cells of a lithium-ion battery were fabricated, and its electrochemical performance under multiple lithiations and delithiations was studied. By means of voltametric studies, it is observed that charging and discharging the anode based on the obtained silicon fibers occurs at potentials from 0.2 to 0.05 V and from 0.2 to 0.5 V, respectively. A change in discharge capacity from 520 to 200 mAh g−1 during the first 50 charge/discharge cycles at a charge current of 0.1 C and a Coulombic efficiency of 98–100% was shown. The possibility of charging silicon-based anode samples at charging currents up to 2 C was also noted; the discharge capacity ranged from 25 to 250 mAh g−1.

Engineering of single atomic Fe-N4 sites on hollow carbon cages to achieve highly reversible MoS2 anodes for Li-ion batteries

Although the single atom electrocatalysts have been demonstrated as efficient catalysts for promoting Li2S/Na2S formation and decomposition in Li-S/Na-S batteries, the functional morphological and structural engineering capable of exposing more active sites is regarded as an essential factor to further enhance the catalytic activity. Here, we have synthesized a single atomically dispersed Fe sites embedded within hollow nitrogen doped carbon cages (Fe-N-HCN) using Fe3O4 spheres as an oxidant and sacrificial template, which is used as a high-efficiency catalyst for boosting the reversible capacity of MoS2 anode in lithium-ion batteries (LIBs). As expected, the electrochemical reaction of MoS2/Fe-N-HCN anode exhibits higher reversibility than pure MoS2 electrodes. Moreover, density functional theory is also employed to reveal that Fe-N-HCN can be effectively adsorbed and catalyze the rapid decomposition of Li2S. The hollow carbon cage structure can facilitate the exposure of the active Fe-N4 sites and favor the mass transfer during the electrochemical reactions, thus the synergistic effect of the Fe-N4 site and the hollow carbon cage structure together improve the catalytic activity for the conversion reaction of MoS2 anode.

Enhancing Durability and Capacity Retention of Ultrafine-Grained Aluminum Foil Anodes in Lithium-Ion Batteries.

In this study, we present our successful fabrication of commercial-grade pure aluminum anode foil (99.5%, 2NAl) with an ultrafine-grained (UFG) microstructure and high hardness, achieved through cold rolling. Under identical rolling conditions, a coarse-grained microstructure with a low hardness was attained from the high-purity Al foil (99.99%, 4NAl). The UFG 2NAl foil exhibited enhanced lithium-ion diffusivity and reduced nucleation and activation overpotentials for forming the β-LiAl phase compared to the 4NAl foil. The high-density grain boundaries in the UFG 2NAl foil facilitated the rapid formation of a uniform β-LiAl phase layer on its surface, thereby mitigating mechanical damage within the β-LiAl phase layer caused by volume changes during the lithiation and delithiation processes. The high hardness of the UFG 2NAl sample effectively prevented macroscopic plastic deformation during cycling, thus preserving the integrity of the β-LiAl phase layer and inhibiting the formation of cracks within the unreacted Al matrix. The collective advantages of reduced overpotential, enhanced Li-ion diffusivity, and high resistance to mechanical damage and plastic deformation in UFG 2NAl contribute to its superior durability and capacity retention compared to the high-purity Al in electrochemical cycling.

Efficient Lithium Transport and Reversible Lithium Plating in Silicon Anodes: Synergistic Design of Porous Structure and LiF‐Rich SEI for Fast Charging

AbstractSilicon (Si) anodes hold great promise for enhancing the energy density of lithium‐ion batteries (LIBs). However, issues such as slow intrinsic kinetics and unstable interfaces caused by significant volume changes hinder the practical deployment of Si anodes. Fast charging is desired by Si‐related issues that worsen Li plating and dead Li, making it essential to overcome these for safe, reversible charging. Herein, a novel approach is proposed by combining structural design and solid electrolyte interface (SEI) modulation to enable efficient and safe fast charging of LIBs. 3D porous micro‐particles consisting of Si nanosheets coated with a pitch‐based carbon layer are successfully prepared. This design provides enhanced ion transport pathways while maintaining the material's intrinsic rate performance and tap density. Furthermore, the designed localized high‐concentration electrolyte (LHCE) exhibits a lower Li+ desolvation energy barrier and leads to the formation of a LiF‐rich SEI, mitigating the Li plating “tip effect” during fast charging, maintaining interface stability, and demonstrating high Coulombic efficiency. Overall, this study highlights the synergistic importance of structure design and SEI regulation in enhancing LIB anodes for fast charging, aiding in developing superior, safe energy storage.

Experimental and numerical study on flow characteristics of dual‐cavity die based on multi‐objective optimization

AbstractSlot die coating is a common method of manufacturing electrodes for lithium‐ion batteries. In this paper, a multi‐objective optimization research on the geometry of dual‐cavity die is investigated based on the numerical simulation of lithium battery anode slurry flow combined with the surface response optimization method. First, we use the Plackett–Burman test method to screen the geometric parameters significantly affecting the optimization objective. Then, based on the Box–Behnken response surface analysis method, we determine the optimal combination of parameters. The results show that the inner cavity radius and slot gap are the main structural variables affecting exit‐velocity uniformity and die deformation. The slot gap and slot length mainly affect the inlet pressure. The coefficient of deviation of exit velocity uniformity and average inlet pressure of the optimized die structure decreased by 51.3% and 7.6%, respectively. This research provides theoretical guidance for the design of slot coating dies.Highlights Screening significant geometric parameters using Plackett–Burman test methodology. Box–Behnken response surface analysis to determine optimal parameters. Velocity uniformity and inlet pressure increased by 51.3% and 7.6%, respectively.

Enhanced high-rate lithium storage of nanosphere composites with in-situ formed graphene interface bridging Ni3Sn4-based nanoparticles and carbon matrix

The nanosphere composites with in-situ formed graphene interface bridging intermetallic Ni3Sn4-based nanoparticles and carbon matrix (Ni3Sn4@g-C) are successfully fabricated through a facile organic–inorganic coordination complex-derived method. In this novel composite, numerous Ni3Sn4-based nanoparticles with a size of 10 ∼ 80 nm are homogeneously decorated in a carbon nanosphere with a diameter of 200 ∼ 400 nm, and at the interfaces between Ni3Sn4-based nanoparticles and the carbon matrix, several layers of graphene are in-situ formed during the fabrication process due to the catalytic effect of Ni species. When used as the anode in lithium ion batteries (LIBs), intermetallic Ni3Sn4 alloy can not only effectively alleviate the severe volume variation of Sn due to the incorporation of Ni component, but also further improve the mechanical stability and enhance the electrical conductivity of the resultant product owing to the formation of the graphene interface layers. As a result, the hierarchical Ni3Sn4@g-C composite displays high reversible capacities (547.0 mAh/g after 200 cycles at 200 mA g−1, and 542.8 mAh/g after 500 cycles at 1000 mA g−1), excellent cycling stability and superior rate properties (341.3 mAh/g even at a high rate of 2 A g−1). The unique microstructures and special introduction of Ni element in the hierarchical Ni3Sn4@g-C nanospheres are responsible for the enhanced electrochemical lithium storage properties.

Low-cost porous silicon material based on fenton process assisted chemical etching and its application as anode for lithium-ion battery

Nanostructured silicon-based materials are considered as one of the most promising alternatives for anode electrodes of lithium-ion batteries. Nevertheless, the relatively high cost and complexity of most present processes make them difficult to scale up. In this manuscript, we would like to introduce a porous anode prepared by Fenton reaction-assisted chemical etching of low-cost ferrosilicon in the mixed solution of hydrogen fluoride and hydrogen peroxide. The experimental results show that hierarchical structures containing both mesopores and micropores can be formed by this convenient room-temperature etching process and its electrochemical performance as the anode is comparable to that of commercial product. Furthermore, the low cost of ferrosilicon ($1200~1500/ton) compared with the silicon powder of industrial grade (~$3000/ton) traditionally used in Li-ion battery anode preparation also renders this method potential and feasible for large-scale production of Si-based anode materials.

Stress-Relief Engineering in a N-Doped C-Modified Hierarchical Nanoporous Si Anode with a Microcurved Pore Wall Structure for Enhanced Lithium Storage.

The commercialization of alloy-type anodes has been hindered by rapid capacity degradation due to volume fluctuations. To address this issue, stress-relief engineering is proposed for Si anodes that combines hierarchical nanoporous structures and modified layers, inspired by the phenomenon in which structures with continuous changes in curvature can reduce stress concentration. The N-doped C-modified hierarchical nanoporous Si anode with a microcurved pore wall (N-C@m-HNP Si) is prepared from inexpensive Mg-55Si alloys using a simple chemical etching and heat treatment process. When used as the anode for lithium-ion batteries, the N-C@m-HNP Si anode exhibits initial charge/discharge specific capacities of 1092.93 and 2636.32 mAh g-1 at 0.1 C (1 C = 3579 mA g-1), respectively, and a stable reversible specific capacity of 1071.84 mAh g-1 after 200 cycles. The synergy of the hierarchical porous structure with a microcurved pore wall and the N-doped C-modified layer effectively improves the electrochemical performance of N-C@m-HNP Si, and the effectiveness of stress-relief engineering is quantitatively analyzed through the theory of elastic bending of thin plates. Moreover, the formation process of Li15Si4 crystals, which causes substantial mechanical stress, is investigated using first-principles molecular dynamic simulations to reveal their tendency to occur at different scales. The results demonstrate that the hierarchical nanoporous structure helps to inhibit the transformation of amorphous LixSi into metastable Li15Si4 crystals during lithiation.

Pristine cobalt humic acid xerogels embedded with ultrafine cobalt sulfide for enhanced and stable lithium-ion storage

The electrochemical performance of pristine metal–organic xerogels as anodes in lithium-ion batteries is reported for the first time. We propose a novel synthesis approach for the in situ generation of highly dispersed, ultrafine cobalt sulfide nanoparticles on humic acid gels (CoSHA). The CoS nanoparticles in CoSHA have an average diameter of approximately 3 nm. CoSHA electrodes demonstrate enhanced lithium storage capacity, delivering a capacity of 662 mAh g−1 at 0.1 A g−1. They also show stable long-term cycling performance, with no capacity decay after 900 cycles at 1.0 A g−1. Furthermore, our experiments indicate that the improved lithium-ion adsorption results from the oxygen-containing functional groups in humic acid and the ultrafine CoS active sites. This study offers a practical methodology for synthesizing ultrafine metal sulfides and new insights into using pristine gel-based electrodes for energy storage and conversion.

Effect of Carbonization Temperature on the Structure of Pitch Carbon and Its Low-temperature Lithium Storage Properties

Introduction:: Lithium-ion batteries were one of the most promising battery systems for electric vehicles. Currently, lithium-ion batteries are required to have higher energy density and cycle stability. The traditional graphite negative electrode cannot meet the requirements. Pitch has many advantages such as wide source, low cost, high carbon residue rate and easy graphitization, as a carbon precursor has been widely used in lithium-ion battery anode and anode materials. Method:: In this paper, pitch carbon was prepared by carbonization at different temperatures and studied. Result:: The results showed that with the increase of carbonization temperature, the interlayer spacing decreased gradually, the degree of amorphousness decreases gradually, the specific surface area and pore volume also decrease gradually, the initial coulombic efficiency and capacity retention increased, and the discharge-specific capacity decreased. Galvanostatic Intermittent Titration Technique (GITT) tests show that there are two main mechanisms of lithium ions intercalation in the material, surface adsorption and interlayer intercalation. Conclusion:: The difficulty of diffusion of lithium ions between pitch carbon layers at low temperatures is the main reason for the decrease of its capacity at low temperature. The carbon material obtained by carbonization of pitch at 800℃ has the best low temperature performance, with discharge specific capacities of 335, 272, 232 and 187mAh/g at 25, 0, -20 and -40℃, of which 55.8% of the discharge specific capacity at room temperature can be retained at -40℃. The amorphous carbon material has certain low temperature charge-discharge performance.