{"id":{"repo_id":"cambridge","oai_identifier":"oai:www.repository.cam.ac.uk:1810/354053"},"canonical_url":"https://search.dev.ndltd.org/etd/cambridge/oai:www.repository.cam.ac.uk:1810/354053","repository":{"repo_id":"cambridge","name":"Cambridge University","base_url":"https://api.repository.cam.ac.uk/server/oai/request"},"display":{"title":"Functional Metal Oxide Coatings from Molecular Precursors for Energy Applications","abstract":"The ability to create and optimise new interfaces is essential to develop and optimise materials for use in sustainable energy storage and conversion technologies. In this thesis, the solution-deposition of coatings from molecular precursors is explored as a promising approach towards this end. First, a facile method for the deposition of electrocatalytically active zirconium-based films for photoelectrochemical water oxidation is developed. The films were derived from three novel alkoxy cage compounds containing Zr and a first-row transition metal (Co, Fe or Cu). The deposition of a Co-doped ZrO2 coating onto the BiVO4 photoanode lowers its onset potential by 0.12 V to 0.21 V vs. the reversible hydrogen electrode (RHE) and increases the maximum photocurrent density by ∼50% to 2.41 mA cm-2 compared to the uncoated BiVO4. In the next chapter, a new solution deposition method to coat the Li-ion battery cathode LiNi0.8Mn0.1Co0.1O2 (NMC811) with Al2O3 using aluminium isopropoxide (AIP) is developed. High-field solid-state nuclear magnetic resonance spectroscopy (SSNMR) probes the formation of γ-LiAlO2 at 600 °C and doping of aluminium into NMC811 starting at 500 – 600 °C. NMC811 coated with amorphous Al2O3 (200 – 400 °C) had a capacity retention comparable to pristine NMC811, while higher annealing temperatures led to more crystalline coatings and surface Al-doping which were found to increase the rate of degradation of NMC811 upon cycling. Finally, LiAlO2 coatings are deposited onto NMC811 using heterobimetallic alkoxides: LiAl[(OCH2Ph)4], LiAl[(OiPr)4] and LiAl[(OtBu)4]. The later showing the most promise as a coating precursor due to its high solubility in tetrahydrofuran (THF), low temperature decomposition (283 °C) and reaction with hydroxyl groups present on the surface of NMC811. This coating was tested on polycrystalline NMC811 (PC-NMC811) and Al2O3 coated single-crystal NMC811 (Al2O3/SC-NMC811). Significant improvements in capacity retention (17.2% more C/2 capacity retained after 107 cycles vs. Al2O3/SC-NMC811) were seen in the LiAlO2/Al2O3/SC-NMC811 system. Furthermore, coating PC-NMC811 that was previously degraded by soaking in water improved the capacity retention (50.1% more capacity retention at C/2 after 215 cycles vs. uncoated PC-NMC811 soaked in water and annealed at 400 °C) suggesting that the combination of a LiAlO2 coating and subsequent annealing step can recover NMC811 surfaces that have been previously degraded by soaking in water.","abstract_html":"The ability to create and optimise new interfaces is essential to develop and optimise materials for use in sustainable energy storage and conversion technologies. In this thesis, the solution-deposition of coatings from molecular precursors is explored as a promising approach towards this end. First, a facile method for the deposition of electrocatalytically active zirconium-based films for photoelectrochemical water oxidation is developed. The films were derived from three novel alkoxy cage compounds containing Zr and a first-row transition metal (Co, Fe or Cu). The deposition of a Co-doped ZrO<sub>2</sub> coating onto the BiVO<sub>4</sub> photoanode lowers its onset potential by 0.12 V to 0.21 V vs. the reversible hydrogen electrode (RHE) and increases the maximum photocurrent density by ∼50% to 2.41 mA cm<sup>-2</sup> compared to the uncoated BiVO<sub>4</sub>. In the next chapter, a new solution deposition method to coat the Li-ion battery cathode LiNi<sub>0.8</sub>Mn<sub>0.1</sub>Co<sub>0.1</sub>O<sub>2</sub> (NMC811) with Al<sub>2</sub>O<sub>3</sub> using aluminium isopropoxide (AIP) is developed. High-field solid-state nuclear magnetic resonance spectroscopy (SSNMR) probes the formation of γ-LiAlO<sub>2</sub> at 600 °C and doping of aluminium into NMC811 starting at 500 – 600 °C. NMC811 coated with amorphous Al<sub>2</sub>O<sub>3</sub> (200 – 400 °C) had a capacity retention comparable to pristine NMC811, while higher annealing temperatures led to more crystalline coatings and surface Al-doping which were found to increase the rate of degradation of NMC811 upon cycling. Finally, LiAlO<sub>2</sub> coatings are deposited onto NMC811 using heterobimetallic alkoxides: LiAl[(OCH<sub>2</sub>Ph)<sub>4</sub>], LiAl[(O<sup>i</sup>Pr)<sub>4</sub>] and LiAl[(O<sup>t</sup>Bu)<sub>4</sub>]. The later showing the most promise as a coating precursor due to its high solubility in tetrahydrofuran (THF), low temperature decomposition (283 °C) and reaction with hydroxyl groups present on the surface of NMC811. This coating was tested on polycrystalline NMC811 (PC-NMC811) and Al<sub>2</sub>O<sub>3</sub> coated single-crystal NMC811 (Al<sub>2</sub>O<sub>3</sub>/SC-NMC811). Significant improvements in capacity retention (17.2% more C/2 capacity retained after 107 cycles vs. Al<sub>2</sub>O<sub>3</sub>/SC-NMC811) were seen in the LiAlO<sub>2</sub>/Al<sub>2</sub>O<sub>3</sub>/SC-NMC811 system. Furthermore, coating PC-NMC811 that was previously degraded by soaking in water improved the capacity retention (50.1% more capacity retention at C/2 after 215 cycles vs. uncoated PC-NMC811 soaked in water and annealed at 400 °C) suggesting that the combination of a LiAlO<sub>2</sub> coating and subsequent annealing step can recover NMC811 surfaces that have been previously degraded by soaking in water.","abstract_has_math":false,"creators":["Riesgo Gonzalez, Victor"],"institution":"University of Cambridge","degree_name":"Doctor of Philosophy (PhD)","degree_level":"Doctoral","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Wright, Dominic","Grey, Clare"],"committee_chairs":[],"committee_members":[],"year":2023,"date_issued":"2023-03-28","date_published":"2023-03-28","updated_at":"2026-07-24T01:32:57Z","subjects":["Batteries","Chemistry","Coatings","Deposition","Electrocatalysis","Electrochemistry","Inorganic","Materials","Molecular","Oxides","Precursors","Single-source","Synthesis"],"languages":["eng"],"rights":[],"rights_urls":["https://www.repository.cam.ac.uk/bitstreams/0954b7c9-ef66-472d-9f1d-82562a96b26f/download","https://www.rioxx.net/licenses/all-rights-reserved/"],"identifier_entries":[]},"links":{"outbound_url":"https://doi.org/10.17863/CAM.100062","outbound_label":"DOI","outbound_source":"dc:identifier.doi"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Wright, Dominic","Grey, Clare"]},{"key":"dc:creator","label":"Author","values":["Riesgo Gonzalez, Victor"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.issued","label":"Date","values":["2023-03-28"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Cambridge"]},{"key":"dc:relation.isreferencedby.uri","label":"Dc Relation Isreferencedby URI","values":["https://www.repository.cam.ac.uk/handle/1810/354053"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["Doctoral"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["Doctor of Philosophy (PhD)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Batteries","Chemistry","Coatings","Deposition","Electrocatalysis","Electrochemistry","Inorganic","Materials","Molecular","Oxides","Precursors","Single-source","Synthesis"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["https://www.repository.cam.ac.uk/bitstreams/0954b7c9-ef66-472d-9f1d-82562a96b26f/download","https://www.rioxx.net/licenses/all-rights-reserved/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.doi","label":"DOI","values":["https://doi.org/10.17863/CAM.100062"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://www.repository.cam.ac.uk/bitstreams/aacaf5d0-b660-40ae-af64-336cf7766929/download"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The ability to create and optimise new interfaces is essential to develop and optimise materials for use in sustainable energy storage and conversion technologies. In this thesis, the solution-deposition of coatings from molecular precursors is explored as a promising approach towards this end. First, a facile method for the deposition of electrocatalytically active zirconium-based films for photoelectrochemical water oxidation is developed. The films were derived from three novel alkoxy cage compounds containing Zr and a first-row transition metal (Co, Fe or Cu). The deposition of a Co-doped ZrO2 coating onto the BiVO4 photoanode lowers its onset potential by 0.12 V to 0.21 V vs. the reversible hydrogen electrode (RHE) and increases the maximum photocurrent density by ∼50% to 2.41 mA cm-2 compared to the uncoated BiVO4. In the next chapter, a new solution deposition method to coat the Li-ion battery cathode LiNi0.8Mn0.1Co0.1O2 (NMC811) with Al2O3 using aluminium isopropoxide (AIP) is developed. High-field solid-state nuclear magnetic resonance spectroscopy (SSNMR) probes the formation of γ-LiAlO2 at 600 °C and doping of aluminium into NMC811 starting at 500 – 600 °C. NMC811 coated with amorphous Al2O3 (200 – 400 °C) had a capacity retention comparable to pristine NMC811, while higher annealing temperatures led to more crystalline coatings and surface Al-doping which were found to increase the rate of degradation of NMC811 upon cycling. Finally, LiAlO2 coatings are deposited onto NMC811 using heterobimetallic alkoxides: LiAl[(OCH2Ph)4], LiAl[(OiPr)4] and LiAl[(OtBu)4]. The later showing the most promise as a coating precursor due to its high solubility in tetrahydrofuran (THF), low temperature decomposition (283 °C) and reaction with hydroxyl groups present on the surface of NMC811. This coating was tested on polycrystalline NMC811 (PC-NMC811) and Al2O3 coated single-crystal NMC811 (Al2O3/SC-NMC811). Significant improvements in capacity retention (17.2% more C/2 capacity retained after 107 cycles vs. Al2O3/SC-NMC811) were seen in the LiAlO2/Al2O3/SC-NMC811 system. Furthermore, coating PC-NMC811 that was previously degraded by soaking in water improved the capacity retention (50.1% more capacity retention at C/2 after 215 cycles vs. uncoated PC-NMC811 soaked in water and annealed at 400 °C) suggesting that the combination of a LiAlO2 coating and subsequent annealing step can recover NMC811 surfaces that have been previously degraded by soaking in water."]},{"key":"dc:format.checksum.md5","label":"Dc Format Checksum Md5","values":["fb11570e508df68bbcbb1c36b5542723","87eda9de84448d1f82354d60eee3eb5f"]},{"key":"dc:title","label":"Title","values":["Functional Metal Oxide Coatings from Molecular Precursors for Energy Applications"]}]}],"canonical_facts":{"dc:contributor.advisor":["Wright, Dominic","Grey, Clare"],"dc:creator":["Riesgo Gonzalez, Victor"],"dc:date.issued":["2023-03-28"],"dc:description.abstract":["The ability to create and optimise new interfaces is essential to develop and optimise materials for use in sustainable energy storage and conversion technologies. In this thesis, the solution-deposition of coatings from molecular precursors is explored as a promising approach towards this end. First, a facile method for the deposition of electrocatalytically active zirconium-based films for photoelectrochemical water oxidation is developed. The films were derived from three novel alkoxy cage compounds containing Zr and a first-row transition metal (Co, Fe or Cu). The deposition of a Co-doped ZrO2 coating onto the BiVO4 photoanode lowers its onset potential by 0.12 V to 0.21 V vs. the reversible hydrogen electrode (RHE) and increases the maximum photocurrent density by ∼50% to 2.41 mA cm-2 compared to the uncoated BiVO4. In the next chapter, a new solution deposition method to coat the Li-ion battery cathode LiNi0.8Mn0.1Co0.1O2 (NMC811) with Al2O3 using aluminium isopropoxide (AIP) is developed. High-field solid-state nuclear magnetic resonance spectroscopy (SSNMR) probes the formation of γ-LiAlO2 at 600 °C and doping of aluminium into NMC811 starting at 500 – 600 °C. NMC811 coated with amorphous Al2O3 (200 – 400 °C) had a capacity retention comparable to pristine NMC811, while higher annealing temperatures led to more crystalline coatings and surface Al-doping which were found to increase the rate of degradation of NMC811 upon cycling. Finally, LiAlO2 coatings are deposited onto NMC811 using heterobimetallic alkoxides: LiAl[(OCH2Ph)4], LiAl[(OiPr)4] and LiAl[(OtBu)4]. The later showing the most promise as a coating precursor due to its high solubility in tetrahydrofuran (THF), low temperature decomposition (283 °C) and reaction with hydroxyl groups present on the surface of NMC811. This coating was tested on polycrystalline NMC811 (PC-NMC811) and Al2O3 coated single-crystal NMC811 (Al2O3/SC-NMC811). Significant improvements in capacity retention (17.2% more C/2 capacity retained after 107 cycles vs. Al2O3/SC-NMC811) were seen in the LiAlO2/Al2O3/SC-NMC811 system. Furthermore, coating PC-NMC811 that was previously degraded by soaking in water improved the capacity retention (50.1% more capacity retention at C/2 after 215 cycles vs. uncoated PC-NMC811 soaked in water and annealed at 400 °C) suggesting that the combination of a LiAlO2 coating and subsequent annealing step can recover NMC811 surfaces that have been previously degraded by soaking in water."],"dc:format.checksum.md5":["fb11570e508df68bbcbb1c36b5542723","87eda9de84448d1f82354d60eee3eb5f"],"dc:identifier.doi":["https://doi.org/10.17863/CAM.100062"],"dc:identifier.uri":["https://www.repository.cam.ac.uk/bitstreams/aacaf5d0-b660-40ae-af64-336cf7766929/download"],"dc:language":["eng"],"dc:publisher.institution":["University of Cambridge"],"dc:relation.isreferencedby.uri":["https://www.repository.cam.ac.uk/handle/1810/354053"],"dc:rights":["https://www.repository.cam.ac.uk/bitstreams/0954b7c9-ef66-472d-9f1d-82562a96b26f/download","https://www.rioxx.net/licenses/all-rights-reserved/"],"dc:subject":["Batteries","Chemistry","Coatings","Deposition","Electrocatalysis","Electrochemistry","Inorganic","Materials","Molecular","Oxides","Precursors","Single-source","Synthesis"],"dc:title":["Functional Metal Oxide Coatings from Molecular Precursors for Energy Applications"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["Doctoral"],"dc:type.qualificationname":["Doctor of Philosophy (PhD)"]},"updated_at":"2026-07-24T01:32:57Z"}