Mesoporous nickel - an odyssey through synthesis, characterisation and application to electrochemical power devices

This thesis describes the synthesis, characterisation and application of mesoporous nickel to electrochemical technologies. Mesoporous nickel was synthesised by electroreduction of nickel salts within the aqueous domains of self-assembled liquid crystalline templates. These materials were characterised structurally and electrochemically.

Materials with both hexagonal and bicontinuous cubic pore geometry with pore sizes of the former between 3.5 and 7 nm were fabricated with appropriate selection of the surfactant template and deposition conditions. Pores were shown to be of uniform diameter and possessing long range continuity. Electrochemical characterisation revealed a very high capacity for charge storage in alkaline solution (up to 824 mC cm^-2 for a 0.65 μm thick electrode), coupled with extremely rapid rates of charge transfer.

These properties were used to create a supercapacitor device utilising aqueous chemistry and consisting of all-mesoporous electrodes with exceptionally high power and energy densities. Cyclic voltammetry and potential step experiments demonstrated delivery of 222 mC cm^-2 or 166 mA.h g^-1 (of nickel electrode) in 50 ms at a mean discharge voltage of 1.18 V using an aqueous electrolyte. This translates into energy and power densities of 706 kJ kg^-1 and 14.1 MW kg^-1 respectively for the Ni/Ni(OH)₂ electrode. Cycling behaviour of this device was also unique in that charge storage capacity was observed to increase by 10% over 15000 cycles.

University of Southampton

Nelson, Phillip Andrew

8244fe4a-6b5d-4587-ae48-acd93ab291c9

2003

Nelson, Phillip Andrew

8244fe4a-6b5d-4587-ae48-acd93ab291c9

Nelson, Phillip Andrew (2003) Mesoporous nickel - an odyssey through synthesis, characterisation and application to electrochemical power devices. University of Southampton, Doctoral Thesis.

Record type: Thesis (Doctoral)