Cycle Life Of Lithium-ion Batteries Research Articles

Silicon-Based Nanocomposite Anodes with Excellent Cycle Life for Lithium-Ion Batteries Achieved by the Synergistic Effect of Two Silicides

Nanocomposite electrodes comprising LaSi2 and Si exhibit satisfactory charge–discharge cycling performances but their capacity is degraded after repeated cycles. A metallographic structure, in which the Si phase was finely dispersed in the LaSi2 matrix phase, was formed before cycling. The elastic LaSi2 relieved Si-generated stress and suppressed electrode disintegration. Contrarily, the LaSi2 phase in the metallographic structure was surrounded by the Si matrix phase after cycling. The positional relationship between the two phases was reversed, and LaSi2 could not relieve the stress. For a nanocomposite electrode containing CrSi2, which exhibits stiffness to withstand the Si-generated stress, the structural changes were suppressed after cycling, resulting in good cycling stability. Here, we considered that the addition of stiff silicides as a third phase to the LaSi2/Si composite could improve the cycle life. Thus, this study prepared nanocomposite electrodes containing elastic LaSi2, stiff MSi2 (where M = Cr, Mo, Nb, Ta, Ti, or W), and elemental Si and investigated their electrochemical performances. Reaction behaviors, such as the metallographic structure, electrode thickness, and phase transition, were also clarified. The LaSi2/NbSi2/Si electrode exhibited the best cycle life without changes in its metallographic structure owing to the synergistic effect of stiff and elastic silicides.

Facile synthesis of BiNbO4@C composite as novel high-performance anode materials for long cycle life lithium-ion batteries

Bismuth-based materials are considered highly promising for lithium-ion batteries due to their appropriate lithiation potential and high theoretical capacity. In this study, a carbon-coated BiNbO4 composite was synthesized using the molten salt method combined with mechanical ball milling and explored as a novel anode material for lithium-ion batteries. After 300 cycles of testing, the composite electrode synthesized has a reversible capacity of 401 mA h g−1 at 100 mA g−1, which exceeds that of a commercial graphite anode. Moreover, the long-cycle stability experiments show that the reversible capacity of the BiNbO4@C composite is 220 mA h g−1 and 180 mA h g−1, with corresponding test parameters of 500 mA g−1 for 1200 cycles and 1000 mA g−1 for 1000 cycles, respectively. The findings of this research serve as a valuable guide for enhancing the utilization of this material in lithium-ion battery applications.

LFO modified separator for the initial anode irreversibility compensation in lithium-ion rechargeable full cells

Lithium-ion batteries (LIBs) dominate portable electronics and electric vehicles for their high energy density and long cycle life. However, a part of active Li loss in the initial charge process for the solid electrolyte interphase (SEI) formation at the anode surface, which reduces the energy density and cycle life of LIBs. Prelithiation attempts have been widely regarded as providing additional active lithium to address this issue. Li5FeO4 (LFO) as a cathode prelithiation additive with high donable lithium ions is very promising. But the residues of the gas release limited its further application due to its low conductivity in the first charge process. Here, we prepared CNT/ Polyacrylonitrile (PAN) /LFO/polypropylene (PP) separator by an electrospinning method, the CNT/PAN/LFO/PP separator can effectively improve cycle performance of LFP batteries, benefiting from Li2O participation in the construction of SEI and higher infiltration rate of the electrolyte resulting in faster interfacial Li+ transfer kinetics. The LFP pouch cell with CNT/PAN/LFO/PP separator can maintain a stable output over 1000 cycles (capacity fade rate per cycle of 0.005 %) with a highercapacity increased by 6.2 %.

In-situ surface growth strategy to synthesize MXene@graphdiyne heterostructure for achieving high capacity and desirable stability in lithium-ion batteries

Two-dimensional (2D) heterostructured electrodes, combining graphdiyne (GDY) and MXenes, have exhibited substantial promise in augmenting the mobility of both ionic and electron movement. However, the widespread advancement and industrial utilization have been impeded by intricate manufacturing procedures and insufficient stability. This study introduces a more streamlined, in-situ growth approach for preparing MXene@GDY electrodes, presenting a novel heterostructure. The method simplifies the manufacturing process while enhancing the specific capacity of the electrode and the more stable cycle life of lithium-ion batteries (LIBs). The resulting electrode exhibited an impressive initial specific capacity of 464.4 mA h g−1, maintaining a high capacity of 492.9 mA h g−1 after 100 cycles at 100 mA current density. More importantly, after 1200 cycles, MXene@GDY showed a capacity of 340.7 mA h g−1, significantly outperforming pure MXene, which only reached 122.3 mA h g−1 at a current density of 1.0 A g−1. The proposed in-situ construction of heterojunction on the MXene surface has demonstrated immense potential for designing high-performance electrode materials which are applicable to LIBs.

Facile fabrication of fibrous phosphorus as anode material for lithium-ion batteries with long cycle life and high rate performance

A facile dual-temperature zone heating strategy has been developed to fabricate fibrous phosphorus (FP) through bottom-up growth with the aid of the Sn24P19.3I8 catalyst. The resultant FP exhibits a high purity of over 99 % and a unique long-term ordering lamellar structure. The as-prepared FP is further mixed with graphite (G) to construct a FP-G composite anode for lithium-ion batteries (LIBs). Compared to conventional crystalline red phosphorus, the developed FP shows higher conductance, smaller lateral dimensions, shorter Li+ transport distance, and faster ion diffusion. This ensures that the FP-G anode gains high rate performance and long cycle life for LIBs. The FP-G anode not only exhibits a high specific capacity of 1533.2 mA h g−1 at 0.5 A g−1 but also presents a high retention capacity of 1048.4 mA h g−1 at a high current density of 4.0 A g−1 after 1300 charge/discharge cycles, indicating a high cycle stability and fast reaction kinetics. Such outstanding characteristics are attributed to the unique lamellar fibrous texture and high aspect ratio of the developed FP, which provides more active sites and structural stability for the electrode material. This study provides a new approach for developing phosphorus-based electrode materials and expands their application range in LIBs.

Zwitterion grafted polyimide separator for improving lithium-ion transport and its application in LiCoO2 batteries

To improve the lithium-ion transport ability and cycle life of lithium-ion batteries, a high-performance polyimide-based lithium-ion battery separator (PI-SO3) was prepared by chemically grafting zwitterion onto the surface of heat-resistant polyimide nanofiber matrix with the assistance of amino-rich polyethyleneimine (PEI). The PI-SO3 not only maintains good dimensional stability (over 200 °C) and flame retardancy, but also ensures the safety of the battery under extreme conditions. Electrochemical experimental results show that PI-SO3 has high ion conductivity (1.99 mS·cm−1), Li+ transference number (0.632), and excellent oxidation potential (5.28 V), which are all higher than those of pure PI separator (1.14 mS·cm−1, 0.444, and 4.56 V, respectively). Meanwhile, LiCoO2/PI-SO3/Li batteries exhibit excellent high-rate performance (139.5 mAh·g−1 at 5C current) and long-term cycle stability (138.9 mAh·g−1 after 100 cycles at 1C current, and 127.9 mAh·g−1 after 100 cycles at 2C current). In addition, the symmetrical battery, Li/PI-SO3/Li, shows stable more than 360 cycles. Compared with batteries using commercial separators, such as Celgard 2325 and pure polyimide matrix, the assembled coin cells with PI-SO3 separators have higher lithium-ion conductivity, Li+ transference number, and diffusion coefficient after grafting zwitterion, showing better rate ability and capacity retention. In this paper, the modification strategy of thermal-resistant separator by grafting zwitterions provides an efficient way to prepare next generation high-performance lithium-ion batteries with good safety.

Two strain modes and transition point of 18650 lithium-ion battery at different charging rates

The safety issues of lithium-ion batteries are one of the biggest obstacles restricting the development of lithium-ion batteries. Excessive charging rate is not conducive to extending the cycle life of lithium-ion batteries. However, there is a lack of research on the upper limit of the charging rate of lithium batteries. The strain of the battery can reflect the change of the internal material during the charging process. The purpose of this study is to explore the charging rate of the strain transition point of lithium-ion batteries and the strain characteristics of the batteries after exceeding this rate. The experiments conducted at different rates and temperatures on battery strain revealed that the transition point of strain in the battery occurs at a rate of 2C. When the charging rate is lower than 2C, the battery strain increases monotonically, which is similar to the step response of the first-order system. When the charging rate exceeds 2C, the battery strain experiences excessive strain due to severe lithium plating, showing a step response similar to a second-order system with a spike representing an overshoot phenomenon. As the charging rate continues to increase, the overshoot peak of the battery ‘s strain becomes more obvious. The experimental results confirm that the charging rate of the 18,650 ternary lithium-ion battery used in the experiment should not exceed 2C, as it would lead to excessive strain in the battery.

Cycle life and influencing factors of cathode materials for lithium-ion batteries--a case study of lithium-cobalt oxides

Abstract Lithium-cobalt oxide has become a new generation of highly promising anode materials for lithium-ion batteries due to its low price, environmental friendliness, high platform voltage, and high theoretical capacity. In this paper, the working characteristics and related parameters of lithium-ion batteries are sorted out, and the influence factors of the decline mechanism of lithium-ion batteries are investigated from the perspective of chemical composition. Regarding the cycle life of lithium-ion battery cathode materials, this paper establishes a cycle life prediction model for lithium-ion batteries based on the LSTM model. It optimizes the hyperparameters of the model using the PSO algorithm. In addition, this paper also prepared lithium cobalt oxide cathode materials and carried out a validation analysis of the factors affecting their electrochemical performance. It is found that the cycle life prediction of lithium-ion battery based on LSTM has an RMSE of 3.27%, and the capacity of lithium cobalt oxide soft pack full battery decays from 249.81mAh to 137.04mAh at 26°C. The cycle life of its lithium cobalt oxide lithium-ion battery is around 250 cycles, and the average decay is 0.445mAh during one charge/discharge. Different charge/discharge cycles and diversity will have a significant effect on the cycle life of lithium-ion battery cathode materials, and it is necessary to pay attention to the parameter changes in the preparation of lithium cobalt oxide cathode materials in order to increase the cycle life of lithium-ion batteries.

Controllable long-term lithium replenishment for enhancing energy density and cycle life of lithium-ion batteries

A controllable and sustainable lithium replenishment strategy was developed to achieve high-energy-density and long-lifespan lithium-ion batteries.

Rapid Test and Assessment of Lithium-ion Battery Cycle Life Based on Transfer Learning

Rapid Test and Assessment of Lithium-ion Battery Cycle Life Based on Transfer Learning

Amorphization of Inorganic Solid Electrolyte Interphase Components and Its Impact on Enhancing Their Transport and Mechanical Properties.

The safety and cycle life of lithium-ion batteries (LIBs) are largely determined by the solid electrolyte interphase (SEI) formed on the surface of the anode. However, there is still a lack of understanding regarding the structure and properties of the individual SEI components. Among others, lithium oxide (Li2O), lithium carbonate (Li2CO3), and lithium fluoride (LiF) are known to be the main components of the inorganic SEI layer in conventional LIBs, but their intrinsic protective roles remain controversial. Herein, we present the transformational effects of their amorphous phase on the mechanical and transport characteristics, based on first-principles calculations. Our studies clearly demonstrate that their amorphous phases exhibit significantly improved Li-ion conductivity when compared to the crystalline structures. Additionally, among them, amorphous LiF emerges as a frontrunner for fast Li+ ion transportation, reversing the conventionally understood hierarchy. Under ambient conditions, the amorphous phases of LiF, Li2O, and Li2CO3 are thermodynamically unstable and tend to undergo recrystallization. However, this work highlights that exceptionally ductile and resilient amorphous phases can form if SEI formation and growth would involve some admixing of lithiophilic impurities like nitrogen (N) within the host matrices.

Identifying the calendar aging boundary and high temperature capacity fading mechanism of Li ion battery with Ni-rich cathode

Temperature is well known to have a significant impact on the performance, safety, and cycle life of lithium-ion batteries. Increasing the operating temperature within the limits of safety and performance allowances facilitates the rapid acquisition of the capacity retention capability, enabling the construction of life prediction models. This paper combines the destructive and non-destructive analysis to determine the temperature boundary for LiNi0.8Co0.1Mn0.1O2 cathode based prismatic cells and clarify the aging mechanism of each component under high temperature calendar aging, which provides a great help for the experiment design in the actual application.

A Rapid Test Method Based on Prediction with Swarm Intelligent Optimization and Monte Carlo Expansion for Lithium-Ion Battery Cycle Life

The cycle life test offers significant sustainment for utilization and maintenance of lithium-ion batteries. The traditional way is continuous charge-discharge testing without interruption, which often takes one year or even longer. Therefore, this paper proposes a rapid cycle life test method based on intelligent prediction to replace the continuous test, which shortens the test period and accelerates product replacement. The original capacity data is decoupled into the short-term regeneration trajectory and the long-term degradation trajectory, which are predicted by the long-short term memory model optimized by swarm intelligent algorithm. The data expansion technique based on Monte Carlo sampling is used to increase the diversity of training data to improve the prediction accuracy. The feasibility and effectiveness are proved by NASA data sets. The results show that the cycle life test time reduced by at least 90% with the error less than 3 cycles.

Predicting the Cycle Life of Lithium-Ion Batteries Using Data-Driven Machine Learning Based on Discharge Voltage Curves

Battery degradation is a complex nonlinear problem, and it is crucial to accurately predict the cycle life of lithium-ion batteries to optimize the usage of battery systems. However, diverse chemistries, designs, and degradation mechanisms, as well as dynamic cycle conditions, have remained significant challenges. We created 53 features from discharge voltage curves, 18 of which were newly developed. The maximum relevance minimum redundancy (MRMR) algorithm was used for feature selection. Robust linear regression (RLR) and Gaussian process regression (GPR) algorithms were deployed on three different datasets to estimate battery cycle life. The RLR and GPR algorithms achieved high performance, with a root-mean-square error of 6.90% and 6.33% in the worst case, respectively. This work highlights the potential of combining feature engineering and machine learning modeling based only on discharge voltage curves to estimate battery degradation and could be applied to onboard applications that require efficient estimation of battery cycle life in real time.

Analysis of strategies to maximize the cycle life of lithium-ion batteries based on aging trajectory prediction

Analysis of strategies to maximize the cycle life of lithium-ion batteries based on aging trajectory prediction

Numerical investigation on cooling cylindrical lithium-ion-battery by using different types of nanofluids in an innovative cooling system

Temperature is known to greatly affect the efficiency, security, and cycle life of lithium-ion battery (LiB) cells. LiB cells are delicate to changes in temperature by using a variety of nanofluids. This study uses a novel cooling system with a Re between 15 × 103 and 30 × 103 to lower the cells' temperature. Al2O3, CuO, SiO2, and ZnO with nanoparticles concentrations of 5% and nanoparticle diameters of 20 nm dispersed in a base liquid (water) are used to produce the effects. The findings demonstrate that as the Re rises, so does the Nusselt number. An innovative cooling system is designed and numerically tested to show how different kinds of nanofluids affect the increment in heat transmission and distribution of temperature in LiB cells. The temperature of LiB cells drops by flowing the water between the 52 batteries inside the cooling pack. For each spacing value, the Reynolds numbers are increased, which results in an increase in the average Nusselt numbers. According to the computational fluids dynamics results, the Nusselt number rises with increasing spacing. The results show that Re of 18000, 22000, 25000, 27500, and >30000 are needed for SiO2 nanofluids, Al2O3 nanofluids, ZnO nanofluids, CuO nanofluids, and pure water, respectively, to get battery pack temperature of <40 °C (the typical operating conditions). Higher Re values improve the heat transfer slightly with the expense of pumping power; therefore, Re of 18000 with SiO2 nanofluids is preferred. The utilization of nanofluids also shows that SiO2 exhibits the best thermal cooling for battery packs among all investigated nanofluids. Al2O3 nanofluid is also an excellent option, followed by ZnO nanofluid. For example, the temperature reduction of the hottest battery cell reaches >47, 44, 43, 42, and 42 °C for SiO2 nanofluids, Al2O3 nanofluids, ZnO nanofluids, CuO nanofluids, and pure water, respectively.

Investigation of the Direct Contact Prelithiation of Silicon-Graphite Composite Anodes for Lithium-Ion Batteries

Silicon is a promising anode material for lithium-ion batteries due to its high theoretical capacity. However, current lithium-ion batteries with high silicon shares in the anodes suffer from rapid capacity fading. The continuous reformation of the solid electrolyte interphase due to particle volume changes during lithiation consumes cyclable lithium. Direct contact prelithiation is a method to counteract lithium losses during the formation and operation of lithium-ion batteries. By providing excess lithium to the anodes during battery cell production, the cycle life of lithium-ion batteries can be increased. Within this work, the process characteristics of direct contact prelithiation and its effect on battery performance are investigated experimentally. Therefore, silicon-graphite composite anodes were mechanically prelithiated using lithium foil and incorporated in lithium-ion battery pouch cells. The prelithiation time and the cell pressure were systematically varied to obtain insights in to the process behavior. Additionally, the lithium quantity was controlled by lithium foil thickness and sample geometry. The prelithiation state of the anodes was examined by optical analysis and measurements of the cells’ open circuit voltage. The effect of anode prelithiation on the battery cell cycling behavior showed a cycle life increase of up to 150% compared to reference cells with non-prelithiated anodes.

Early prediction of lithium-ion battery cycle life based on voltage-capacity discharge curves

Accurately predicting the lifetime of lithium-ion batteries is critical for accelerating technological advancements and applications. Nevertheless, the complex aging mechanisms and dynamic operating conditions of lithium-ion batteries have remained major challenges. This paper proposes a method for early predicting lithium-ion batteries cycle life based on weighted least squares support vector machine (WLS-SVM) with health indicators (HIs) as input. The HIs are extracted from lithium-ion batteries voltage-capacity discharge curves, since these curves are easy to measure and strongly correlate to battery cycle life. Taking into account the nonlinearity of batteries cycle life, a support vector machine (SVM) that is capable of strong generalization is used to predict cycle life. As a solution to the problem of misleading results from outlier data in SVM, error square term combined with weight functions is used in this study to improve robustness and prediction accuracy. The datasets of 41 cells are used to verify the proposed early prediction method. The results show that the root mean square error (RMSE) and mean absolute error (MAE) of cycle life prediction results by the proposed method are much lower, and the cycle life early prediction errors of the test cells are all <9 %, which notes that the proposed method is accurate and valid for cycle life early prediction.

Research results further support battery separator's enhanced capabilities

X-SEPA, a membrane-based separator material created to improve the performance of existing battery technologies, and accelerate the development of next-generation batteries, was launched in 2022. Japan's 3DOM Alliance Inc, the firm behind the technology, says that recent studies provide further scientific support for the enhanced charge–discharge cycle life of lithium-ion batteries and lithium metal rechargeable batteries equipped with X-SEPA. Its Singapore-based subsidiary, Noco-Noco Pte Ltd, has also started shipping samples to battery manufacturers worldwide.

Construction of a robust solid electrolyte interphase on Ge anode to achieve a superior long-term cycle life of lithium-ion battery

Alloy-based materials are suffering a huge volume expansion/shrink during the repeated lithium-ion intercalation/deintercalation process, so they always display an unsatisfied electrochemical performance, especially for the cycle life. In this work, we design a localized highly concentrated electrolyte (LHCE) for Ge anode, by dissolving LiFSI in DME/TTE (3:7 by volume). Raman spectra illustrate that most FSI- anions in LHCE coordinate with Li+ ions, producing the solvated structure in form of AGGs or CIPs. XPS spectra prove that the solid electrolyte interphase (SEI) is rich in inorganic phase, such as Li2CO3, Li3N, LiF and Li2O. So the SEI is more stable and thinner, and it can keep the integrity of Ge particles and avoid their crushing during a long-term cycle. Although a serious capacity decrease at around the 30th cycle is found in esters electrolytes, the similar phenomenon is never seen in LHCE. The PM-550 @Ge in LHCE remains a reversible capacity of 1040 mAh g−1 after 300 cycles at 0.5 A g−1, and the capacity retention ratio is as high as 84%. Even after a long cycling of 500 cycles, the PM-550 @Ge delivers a high reversible capacity of 951 mAh g−1 at 1.0 A g−1.