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Showing 1 to 20 of 42 for “"Capacity Fade"”.
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Capacity Fade Analysis and Model Based Optimization of Lithium-ion Batteries
… stress-induced material damage, capacity fade, and the potential for thermal runaway. This dissertation contributes to the efforts in the modeling, simulation and optimization of lithium-ion batteries and their use in the design of better batteries for the future. While …
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A hybrid battery cell voltage equalizer considering thermal behavior and capacity fade characteristics
The thesis focuses on developing a robust, high-fidelity lithium-ion battery model adaptive to changes in operating temperature, aiming for accurate estimation of state of health (SOH). The thesis proposes two novel methods for lithium-ion battery SOH tracking and estimation using the developed …
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Modeling, Simulation, and Analysis of Lithium-Ion Batteries for Grid-Scale Applications
… layer on the battery electrodes to measure capacity fade during operation. This capacity fade mechanism allowed tracking of the site specific effects on battery life.</p> <p>A systems level model for an electric vehicle was also developed to simulate the growth of the SEI layer caused from …
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Non-equilibrium thermodynamics in porous media : battery degradation, and sorption and transport in porous materials
… of fluids in porous materials. The dominant capacity fade mechanism in many lithium-ion batteries is the loss of cyclable lithium to a solid-electrolyte interphase layer on the surface of the negative electrode. I develop a single-particle model of this fade mechanism, based on diffusion of …
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Novel Catholyte and Electrolyte Optimisation for Aqueous Organic Redox Flow Batteries
… in extensive polymerisation, leading to rapid capacity fade. This rapid capacity fade was improved by electrolyte optimisation, and utilising a mixed-salt system of 0.5 M HCl and 0.5 M H3PO4 it was possible to decrease capacity fade, increase coulombic efficiency and access more theoretical …
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Evaluation of the Cycle Profile Effect on the Degradation of Commercial Lithium Ion Batteries
… investigate the effect of cycle profile on the capacity fade of the battery. The pulse-heavy profile was designed to simulate on-road conditions for a typical hybrid electric vehicle, while the simplified square-wave profile was designed to have the same charge throughput as the pulse-heavy …
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Understanding Failure Mechanisms using Multi-Scale Analyses to Improve the Performance of Zinc Metal and Lithium-ion Batteries
… limits are commonly imposed to reduce capacity fade resulting in reduced energy density and cycle life. Safe operation at high temperatures would enable higher power discharge and faster charging. Despite extensive research on high-temperature operation, the physical mechanisms for …
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Supramolecular effects in pyridinium compounds and their application towards practical redox flow battery systems
… chemistry and existing tonne-scale production capacity of both cucurbit[*n*]uril (CB[*n*]) macrocycles and methyl viologen are leveraged to advance an additive concept for AORFBs that enables stable and tuneable multi electron accessibility – without the need for synthetic modification. By …
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Machine learning for applications in chemical and biological engineering
… cycles the battery undergoes before 80% capacity fade. Several, difficult to identify factors can contribute to capacity fade. Even in batteries with the same chemistry, operated using the same conditions, there is considerable cycle life variability. Therefore, the challenge was to build …
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Investigating the Effect of Electrolyte Concentration and Charging Protocol on Materials Utilization in Rechargeable Zinc Manganese Dioxide Batteries
… when cycled to near full one-electron discharge capacity, which is about 280mAh/g for commercially available electrolytic manganese dioxide (EMD). In this one-electron range, discharge occurs by proton insertion producing Mn<sup>+3</sup> which then reverts to γ-MnO<sub>2 </sub>on charging. In the …
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New metastable cathode materials for lithium-ion batteries
… inserted into the structure, with a discharge capacity of 137 mAh/g after 20 cycles at C/20 and room temperature. At 60°C, all the lithium is removed at the end of the first charge at C/20, with subsequent cycles showing reversible insertion of 1.06 Li-ions when cycled between 1.5 and 4.6 V. …
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Developing new techniques to synthesize layered cathode materials for lithium-ion batteries
… up the reaction. One of the main reasons for capacity fade in batteries is cationic mixing between Ni²⁺ and Li⁺. This results in blocking of the Li⁺ path and ultimately poor cyclability. This capacity fade has been successfully minimized in our current work by taking advantage of the high heat …
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In situ studies of surface reactions affecting Li-ion battery failure
… of Li-ion batteries remain poorly understood. Capacity fade in commercially relevant systems can broadly be traced back to the interfaces between the cell components and electrolyte where so-called side reactions occur; such as Li trapping in non-active regions, loss of active electrode …
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Multiscale Modeling, Reformulation, and Efficient Simulation of Lithium-Ion Batteries
… temperatures can lead to internal damage and capacity fade. In extreme cases this can lead to thermal runaway, a dangerous scenario in which energy is rapidly released. In the other end of the temperature spectrum, low temperatures can significantly impede performance by increasing diffusion …
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Self-reporting of Mn ion dissolution and self-stabilization of cathode-electrolyte interface in lithium ion batteries
… Mn dissolution, which is a major cause of the capacity fade for some cathodes, and release of battery additives triggered by electrolyte degradation to self-stabilize the cathode-electrolyte interface. Lithium manganese oxide (LMO) is a promising cathode material for lithium-ion batteries due …
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Lifetime prediction for lithium-ion batteries undergoing fast charging protocols
… enhancing the suitability of MPET for capacity fade predictions. Supervised machine learning algorithms utilizing feature-based correlations for battery lifetime are described. Electrochemical features that go beyond the discharge-only model provide improved lifetime predictions, …
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Intercalation dynamics in lithium-ion batteries
… and describes a new mechanism for current capacity fade through the interactions of these waves with defects in the particle. Size-Dependent Spinodal and Miscibility Gaps: This work demonstrates that the model is powerful enough to predict that the spinodal and miscibility gaps shrink as …
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Structure and properties of the interdiffused phase between lithiated silicon and copper current collector
… to its order of magnitude higher charge carrying capacity compared to conventional graphite electrodes. The main obstacle of using Si electrodes in commercial lithium batteries is the massive volume expansion of the Si electrode under repeated charge cycling, which leads to delamination of the Si …
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Advances in Lithium Ion Batteries Obviate Need for Ultracapacitors in Electric Vehicles
… system. Battery power density, C-ratings, and capacity fade characteristics have improved to the point that coupling an ultracapacitor is no longer necessary. These improvements allow a designer to remove the weight, cost, and volume reserved for the ultracapacitor/converter from the system …
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Three-dimensional electronic resistivity mapping of solid electrolyte interphase and anode active material in lithium-ion batteries
… is believed to be partially responsible for capacity fade in the Si-based anode. However, the in-situ measurement of electronic resistivity of SEI and Si active material has been complicated by ion transport and electronic contributions from other parts of the battery circuit. Ex-situ …
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