{"id":{"repo_id":"waikato-masters","oai_identifier":"oai:researchcommons.waikato.ac.nz:10289/14423"},"canonical_url":"https://search.dev.ndltd.org/etd/waikato-masters/oai:researchcommons.waikato.ac.nz:10289/14423","repository":{"repo_id":"waikato-masters","name":"University Waikato","base_url":"https://researchcommons.waikato.ac.nz/server/oai/request"},"display":{"title":"Fractional modelling of rechargeable batteries","abstract":"To develop a compact battery model, many authors begin by measuring the impedance of a battery over a frequency range of interest. Most of the models in the literature are either Thevenin-style or Randles’ model consisting of one or two RC networks and sometimes a Warburg element. These models are usually based on frequency range that stretches to only 1 mHz. This explains why they require several parameters to accurately reproduce the measured impedance data. In most applications, a battery goes through a charge/discharge cycle daily or even longer. Therefore, it seems logical to measure the impedance of the cell at frequencies reciprocal of period of charge. This corresponds to approximately 11.6 µHZ or lower. The impedance data at lower frequencies shows that any rechargeable battery can be simply modelled with a constant phase element in series with a resistor. Based on this observation, an equivalent circuit model and a mathematical model were proposed in this study. Similar to Randles’ model presented in 1947, the proposed models do not contain a source or any purely reactive element. The models were then fitted to the measured impedance data of both lithium-ion and nickel-metal hydride cells, the linear region of the charge-voltage curve, and the transient recovery tail that results from a step-change in load current.","abstract_html":"To develop a compact battery model, many authors begin by measuring the impedance of a battery over a frequency range of interest. Most of the models in the literature are either Thevenin-style or Randles’ model consisting of one or two RC networks and sometimes a Warburg element. These models are usually based on frequency range that stretches to only 1 mHz. This explains why they require several parameters to accurately reproduce the measured impedance data. In most applications, a battery goes through a charge/discharge cycle daily or even longer. Therefore, it seems logical to measure the impedance of the cell at frequencies reciprocal of period of charge. This corresponds to approximately 11.6 µHZ or lower. The impedance data at lower frequencies shows that any rechargeable battery can be simply modelled with a constant phase element in series with a resistor. Based on this observation, an equivalent circuit model and a mathematical model were proposed in this study. Similar to Randles’ model presented in 1947, the proposed models do not contain a source or any purely reactive element. The models were then fitted to the measured impedance data of both lithium-ion and nickel-metal hydride cells, the linear region of the charge-voltage curve, and the transient recovery tail that results from a step-change in load current.","abstract_has_math":false,"creators":["Hasan, Rahat"],"institution":"The University of Waikato","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Scott, Jonathan B."],"committee_chairs":[],"committee_members":[],"year":2021,"date_issued":"2021","date_published":"2021","updated_at":"2026-07-24T05:57:15Z","subjects":["Modelling","Lithuim-ion","Equivalent circuit model","Frequency domain analysis","Impedance measurement","Rechargeable batteries","thesis with publication"],"languages":[],"rights":["All items in Research Commons are provided for private study and research purposes and are protected by copyright with all rights reserved unless otherwise indicated."],"rights_urls":["https://researchcommons.waikato.ac.nz/bitstreams/e968321c-c7f7-4423-9d36-603023fbb472/download"],"identifier_entries":[]},"links":{"outbound_url":null,"outbound_label":null,"outbound_source":null},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Scott, Jonathan B."]},{"key":"dc:creator","label":"Author","values":["Hasan, Rahat"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.issued","label":"Date","values":["2021"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["The University of Waikato"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["https://hdl.handle.net/10289/14423"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Modelling","Lithuim-ion","Equivalent circuit model","Frequency domain analysis","Impedance measurement","Rechargeable batteries","thesis with publication"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["https://researchcommons.waikato.ac.nz/bitstreams/e968321c-c7f7-4423-9d36-603023fbb472/download","All items in Research Commons are provided for private study and research purposes and are protected by copyright with all rights reserved unless otherwise indicated."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://researchcommons.waikato.ac.nz/bitstreams/0413d76a-fb84-48c8-b7f5-492e773e6bb1/download"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["To develop a compact battery model, many authors begin by measuring the impedance of a battery over a frequency range of interest. Most of the models in the literature are either Thevenin-style or Randles’ model consisting of one or two RC networks and sometimes a Warburg element. These models are usually based on frequency range that stretches to only 1 mHz. This explains why they require several parameters to accurately reproduce the measured impedance data. In most applications, a battery goes through a charge/discharge cycle daily or even longer. Therefore, it seems logical to measure the impedance of the cell at frequencies reciprocal of period of charge. This corresponds to approximately 11.6 µHZ or lower. The impedance data at lower frequencies shows that any rechargeable battery can be simply modelled with a constant phase element in series with a resistor. Based on this observation, an equivalent circuit model and a mathematical model were proposed in this study. Similar to Randles’ model presented in 1947, the proposed models do not contain a source or any purely reactive element. The models were then fitted to the measured impedance data of both lithium-ion and nickel-metal hydride cells, the linear region of the charge-voltage curve, and the transient recovery tail that results from a step-change in load current."]},{"key":"dc:format.checksum.md5","label":"Dc Format Checksum Md5","values":["bd505ad54058ad3a9a5f03da0c9675cb","e14202ab27e47ddb00d33097327ba050","4c7d3a03a6f02de6b3707ff1b5fbc2f5"]},{"key":"dc:title","label":"Title","values":["Fractional modelling of rechargeable batteries"]}]}],"canonical_facts":{"dc:contributor.advisor":["Scott, Jonathan B."],"dc:creator":["Hasan, Rahat"],"dc:date.issued":["2021"],"dc:description.abstract":["To develop a compact battery model, many authors begin by measuring the impedance of a battery over a frequency range of interest. Most of the models in the literature are either Thevenin-style or Randles’ model consisting of one or two RC networks and sometimes a Warburg element. These models are usually based on frequency range that stretches to only 1 mHz. This explains why they require several parameters to accurately reproduce the measured impedance data. In most applications, a battery goes through a charge/discharge cycle daily or even longer. Therefore, it seems logical to measure the impedance of the cell at frequencies reciprocal of period of charge. This corresponds to approximately 11.6 µHZ or lower. The impedance data at lower frequencies shows that any rechargeable battery can be simply modelled with a constant phase element in series with a resistor. Based on this observation, an equivalent circuit model and a mathematical model were proposed in this study. Similar to Randles’ model presented in 1947, the proposed models do not contain a source or any purely reactive element. The models were then fitted to the measured impedance data of both lithium-ion and nickel-metal hydride cells, the linear region of the charge-voltage curve, and the transient recovery tail that results from a step-change in load current."],"dc:format.checksum.md5":["bd505ad54058ad3a9a5f03da0c9675cb","e14202ab27e47ddb00d33097327ba050","4c7d3a03a6f02de6b3707ff1b5fbc2f5"],"dc:identifier.uri":["https://researchcommons.waikato.ac.nz/bitstreams/0413d76a-fb84-48c8-b7f5-492e773e6bb1/download"],"dc:publisher.institution":["The University of Waikato"],"dc:relation.isreferencedby":["https://hdl.handle.net/10289/14423"],"dc:rights":["https://researchcommons.waikato.ac.nz/bitstreams/e968321c-c7f7-4423-9d36-603023fbb472/download","All items in Research Commons are provided for private study and research purposes and are protected by copyright with all rights reserved unless otherwise indicated."],"dc:subject":["Modelling","Lithuim-ion","Equivalent circuit model","Frequency domain analysis","Impedance measurement","Rechargeable batteries","thesis with publication"],"dc:title":["Fractional modelling of rechargeable batteries"],"dc:type":["Thesis"]},"updated_at":"2026-07-24T05:57:15Z"}