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The heat effects of lithium-ion battery cathode could substantially affect the safety and attenuate lifetime of lithium-ion battery. In order to disclose the thermo-electrochemical behaviors of LiFePO 4 battery during charge-discharge process at various rates at 30℃, electrochemical-calorimetric measurements were employed in this study. The results...
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... capacity of battery reduced. For example, the discharge capacity of LiFePO 4 at 0.1C rate is 151.3mAh g -1 , and at 2.0C rate is 144.5 mAh g -1 . In order to verify above analysis results, the crystalline nature of the cathode material LiFePO 4 during cycling at different charge-discharge rates was identified with X-ray diffraction (XRD). Fig. 3 shows the X-ray diffraction (XRD) patterns of the cathode material LiFePO 4 at different charge- discharge rates. All the diffraction peaks deflected to high angle, the relative peak areas and intensities ascended slightly on increasing charge-discharge rates, most of which is 0.5C. These facts elucidate crystalline phase content of ...
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An electrochemical Lithium ion battery model was built taking into account the electrochemical reactions. The polarization was divided into parts which were related to the solid phase and the electrolyte mass transport of species, and the electrochemical reactions. The influence factors on battery polarization were studied, including the active mat...
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... Specific surface area and pore structures Table 1 summarizes specific surface areas, total pore volumes and (Allandin et al., 2014), indicating that heavy metal ions may diffuse into the inner surface of adsorbent. Because of the lithium ion separation and thermal effect during the charging-discharging process of LIBs (Song et al., 2012), the deposition of lithium ions on cathodes reduced the surface areas or available pores (Watanabe et al., 2014). The deposition of lithium ion on the cathode also leads to the volume expansion and shrinkage of the electrodes, and changes in the porosity of electrode materials (Yamanaka et al., 2017). ...
... Compared with LFP and LMO, SLFP and SLMO had slightly higher grain sizes. The size increase may be attributed to the chemical reactions during the charging and discharging processes that left residues of carbon and other impurities (Song et al., 2012). Fig. S2 shows the element mapping of the pristine and spent LFP before and after Cu absorption. ...
... Nevertheless, the adsorption capacities for Cd and Zn were not significantly different on SLFP, LMO and SLMO. As the carbon and other impurities deposition on cathode plate (Al plate) from electrolyte during battery discharging process or the manual dismantling process of SLFP and SLMO, leading to the decrease of their sorption affinity toward heavy metals (Song et al., 2012). Table 3 compares the adsorption capacities of different reported adsorbents. ...
Proper disposal and resource recovery of spent batteries are crucial for environmental protection and sustainability. This study evaluated the adsorption performances of spent lithium iron phosphate (SLFP) and spent lithium manganate (SLMO) cathodes as adsorbents toward heavy metals in water. The effects of adsorption time, initial adsorbate concentrations, and co-existing ions on adsorption kinetics were examined. SLFP and SLMO demonstrated outstanding adsorption capacities for heavy metals that were higher than or comparable with other reported adsorbents. SLFP shows adsorption capacities of 44.28, 39.54, 25.63, and 27.34 mg g⁻¹ for Cu²⁺, Pb²⁺, Cd²⁺ and Zn²⁺, respectively, SLMO achieved similar adsorption capacities (32.51, 31.83, 26.24 and 25.25 mg g⁻¹, respectively). Among different adsorption kinetics model, the pseudo-second-order model described heavy metals adsorption kinetics best with R² over 0.99, implying that chemisorption may be the predominant adsorption mechanism. The adsorption data at equilibrium well fitted the Langmuir isotherm model with R² over 0.96, suggesting that the adsorption process could be endothermic. Cathode materials from of SLIBs may be recycled as adsorbents for heavy metal removal from water, which supports the “waste to treat waste” concept.
... Increasing the current rate may cause the destruction of the cathode material partially which in turn affects the thermal behavior of the battery. Reasonable cycling rates should be chosen to avoid the heat accumulation inside the battery especially for partially deteriorated battery cells [219]. In the LiCoO 2 cathode for the high ranges of state of charge, phase transition can cause a fluctuation in entropy change. ...
Rechargeable lithium ion batteries (LIBs) play a very significant role in power supply and storage. In recent decades, LIBs have caught tremendous attention in mobile communication, portable electronics, and electric vehicles. Furthermore, global warming has become a worldwide issue due to the ongoing production of greenhouse gases. It motivates solutions such as renewable sources of energy. Solar and wind energies are the most important ones in renewable energy sources. By technology progress, they will definitely require batteries to store the produced power to make a balance between power generation and consumption. Nowadays,rechargeable batteries such as LIBs are considered as one of the best solutions. They provide high specific energy and high rate performance while their rate of self-discharge is low. Performance of LIBs can be improved through the modification of battery characteristics. The size of solid particles in electrodes can impact the specific energy and the cyclability of batteries. It can improve the amount of lithium content in the electrode which is a vital parameter in capacity and capability of a battery. There exist diferent sources of heat generation in LIBs such as heat produced during electrochemical reactions, internal resistance in battery. The size of electrode's electroactive particles can directly affect the produced heat in battery. It will be shown that the smaller size of solid particle enhance the thermal characteristics of LIBs. Thermal issues such as overheating, temperature maldistribution in the battery, and thermal runaway have confined applications of LIBs. Such thermal challenges reduce the Life cycle of LIBs. As well, they may lead to dangerous conditions such as fire or even explosion in batteries. However, recent advances in fabrication of advanced materials such as graphene and carbon nanotubes with extraordinary thermal conductivity and electrical properties propose new opportunities to enhance their performance. Since experimental works are expensive, our objective is to use computational methods to investigate the thermal issues in LIBS. Dissipation of the heat produced in the battery can improve the cyclability and specific capacity of LIBs. In real applications, packs of LIB consist several battery cells that are used as the power source. Therefore, it is worth to investigate thermal characteristic of battery packs under their cycles of charging/discharging operations at different applied current rates. To remove the produced heat in batteries, they can be surrounded by materials with high thermal conductivity. Parafin wax absorbs high energy since it has a high latent heat. Absorption high amounts of energy occurs at constant temperature without phase change. As well, thermal conductivity of parafin can be magnified with nano-materials such as graphene, CNT, and fullerene to form a nano-composite medium. Improving the thermal conductivity of LIBs increase the heat dissipation from batteries which is a vital issue in systems of battery thermal management. The application of two-dimensional (2D) materials has been on the rise since exfoliation the graphene from bulk graphite. 2D materials are single-layered in an order of nanosizes which show superior thermal, mechanical, and optoelectronic properties. They are potential candidates for energy storage and supply, particularly in lithium ion batteries as electrode material. The high thermal conductivity of graphene and graphene-like materials can play a significant role in thermal management of batteries. However, defects always exist in nano-materials since there is no ideal fabrication process. One of the most important defects in materials are nano-crack which can dramatically weaken the mechanical properties of the materials. Newly synthesized crystalline carbon nitride with the stoichiometry of C3N have attracted many attentions due to its extraordinary mechanical and thermal properties. The other nano-material is phagraphene which shows anisotropic mechanical characteristics which is ideal in production of nanocomposite. It shows ductile fracture behavior when subjected under uniaxial loadings. It is worth to investigate their thermo-mechanical properties in its pristine and defective states. We hope that the findings of our work not only be useful for both experimental and theoretical researches but also help to design advanced electrodes for LIBs.
... The amounts of heat of 1-wt% Li 2 ZrO 3 -coated LiNi 0.8 Co 0.1 Mn 0.1 O 2 /Li batteries at different conditions are shown in Fig. 10. Figure 11 demonstrates the enthalpy The smaller the rate, the less the total heat, the less the total enthalpy change in the reaction, and the higher safety performance of the battery [37]. Then the amount of heat and enthalpy change for 1-wt% Li 2 ZrO 3 -coated LiNi 0.8 Co 0.1 Mn 0.1 O 2 cell during charge-discharge process is obtained by data treatment as follows: ...
To improve the electrochemical performance of Nickel-rich cathode material LiNi0.8Co0.1Mn0.1O2, an in situ coating technique with Li2ZrO3 is successfully applied through wet chemical method, and the thermoelectrochemical properties of the coated material at different ambient temperatures and charge-discharge rates are investigated by electrochemical-calorimetric method. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) tests demonstrate that the Li2ZrO3 coating decreases the electrode polarizatoin and reduces the charge transfer resistance of the material during cycling. Moreover, it is found that with the ambient temperatures and charge-discharge rates increase, the specific capacity decreases, the amount of heat increases, and the enthalpy change (ΔH) increases. The specific capacity of the cells at 30 °C are 203.8, 197.4, 184.0, and 174.5 mAh g−1 at 0.2, 0.5, 1.0, and 2.0 C, respectively. Under the same rate (2.0 C), the amounts of heat of the cells are 381.64, 645.32, and 710.34 mJ at 30, 40, and 50 °C. These results indicate that Li2ZrO3 coating plays an important role to enhance the electrochemical performance of LiNi0.8Co0.1Mn0.1O2 and reveal that choosing suitable temperature and current is critical for solving battery safety problem.
... Ben Mayza et al. [13] reported total heat generation in 18650-type LiFePO 4 / graphite using ARC at low current rates and estimated thermal runaway temperature for the same cell. Song et al. [14] studied the heat effects of LiFePO 4 coin cell and commented on the exothermic/ endothermic phenomenon during the charge/discharge processes. Nieto et al. [15] developed a thermal model which describes the heat generation behaviour of Li-ion pouch cell at different current rates based on the calculation of heat generation from experimental measurements of internal resistance and entropic coefficient. ...
... The thermodynamic energy balance for LIBs has been discussed in detail by Bernardi et al. [34]. A simplified form given by Equation (4) can be used to express the heat source in the lithium-ion cell [14]. ...
We report here thermal behaviour and various components of heat loss of 18650-type LiFePO4/graphite cell at different testing conditions. In this regard, the total heat generated during charging and discharging processes at various current rates (C) has been quantified in an Accelerating Rate Calorimeter experiment. Irreversible heat generation, which depends on applied current and internal cell resistance, is measured under corresponding charge/discharge conditions using intermittent pulse techniques. On the other hand, reversible heat generation which depends on entropy changes of the electrode materials during the cell reaction is measured from the determination of entropic coefficient at various states of charge/discharge. The contributions of irreversible and reversible heat generation to the total heat generation at both high and low current rates are evaluated. At every state of charge/discharge, the nature of the cell reaction is found to be either exothermic or endothermic which is especially evident at low C rates. In addition, electrochemical impedance spectroscopy measurements are performed on above 18650 cells at various states of charge to determine the components of internal resistance. The findings from the impedance and thermal loss analysis are helpful for understanding the favourable states of charge/discharge for battery operation, and designing better thermal management systems.
... When the C-rate increases, the exothermic process is dominant and the summation of the overall reactions leads to an exothermic process. According to the calorimetric measurements the LFP battery experiences endothermic process at low C-rates 35 of C/10 and C/5, while it shows an exothermic behavior at C-rates greater than C/2 [61]. ...
... Average of absolute value of computed full cell entropy change over the 0-100% SOC range[61].According toFigure 4.1, LCO/graphite cell associates with more entropy change at charge and discharge. Eq. 2.34 shows higher entropy change leads to higher temperature derivative of standard potential. ...
In this work, the heat generation in lithium-ion batteries (LIBs) with different cathode materials in various change and discharge rates is investigated through mathematical modeling and computer simulation. The model employed to investigate the performance of LIBs for the battery with LiFePO4 (LFP) cathode was validated with experimental results obtained in the Advance Energy& Sensor Lab at The University of Akron. For batteries with LiMn2O4 (LMO) and LiCoO2 (LCO) cathode materials the model was validated with experimental results available in open literature. The importance of various heat generation sources in LIBs including reversible heat generation and irreversible heat generation due to activation, concentration and ohmic polarizations for LIBs with LFP, LMO and LCO cathode materials at various battery energy capacities and charge/discharge rates are compared. Moreover, the role of LIB’s different components such as cathode, anode, separator and current collectors in each source of heat generation in LIBs is obtained and the contribution of each component in the total heat generation is discoursed.
... Moreover, the increased temperature difference between the surface and internal temperatures indicates a higher rate of heat transfer. For both the charge and discharge process, it is interesting and important that the temperature change tendency fits well with the results measured by microcalorimeter for LiFePo 4 and LiMn 2 O 4 [18,19]. Therefore, the temperature evolution during the charge-discharge process can be measured accurately using the embedded microsensor. ...
... The smallest increase of temperature occurs in the flattest part of cell's voltage profile (SoC around 40 % -60 %). It follows the expected behavior of Li-ion cells with different SoCs [10] [15]. Furthermore temperature increases faster for more degraded cells (higher slope in the upper part of Fig. 5. ). ...
LiFePO4 is a promising cathode material used in Li-ion batteries. It offers better cyclability and is safer in terms of thermal runaway than previous LiCoO2 or LiMnO2 cathodes. With new applications as electric vehicles (EV) a reliable State-of-Charge (SoC) estimator becomes a must. Cell's degradation or State-of-Health (SoH) is crucial when determining SoC. We aim to find a parameter related to SoH in order to have realiable SoC indicators at any time or condition. Impedance, dynamic resistance and thermodynamics of cells with different degradation levels have been studied. Correlation of SoH and impedance of those cells is not found at a glance. In contrast, dynamic resistance, temperature and entropy show good agreement with SoH evolution.
