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 LiNi_0.8Mn_0.1Co_0.1O₂ (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[(O^tBu)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.