Hydrogen storage and battery technology group

A prototype for synthesis of new on-board hydrogen storage materials (HSMs) has been developed by our team. The hydrogen storage capacity of HSMs have been improved by optimizing the preparation and purification procedures and improving the volumetric and gravimetric capacities, hydrogen adsorption/desorption kinetics, cycle life, and reaction thermodynamics of potential material candidates. 

HSMs for solid-state hydrogen storage applications, have been fabricated which have hydrogen storage gravimetric capacity of 2 wt.% (KgH₂/Kg materials mass) for carbonous nanomaterials at room temperature and 8 wt.% (KgH₂/Kg materials mass) for porous nanomaterials at 150 °C at relatively low pressure (≤ 40 bar).

We are optimizing our hydrogen storage technology to increase the yield and purity of HSMs to achieve large-scale production of related products, reduce cost and improve the efficiency.  

• Carbon-based Nanostructures

Carbon-based nanotubes have been a popular candidate as the sorbent for solid-state hydrogen storage due to the low density, high surface area, and high stability properties. The nanotube structure provides storage sites for hydrogen atoms.

• Composite and Porous Thin Films

A new porous material  for the hydrogen storage has been developed by our team and showed superior hydrogenation properties as it stores hydrogen in porous structure during fabrication by electrochemical etching of hydrofluoric acid. These materials indicated high specific surface area and high chemical activity with hydrogen. Recent breakthroughs from our group in porous materials included that addition of catalyst by Spillover effect resulted in increase of the yield of samples per fabrication batch.

Buckypaper also known as carbon nanotube thin film, is a conductive sheet used in various electronic devices as an electrode conductor. The buckypaper produced in our group is a binder free and free-standing thin film. It is famous for its light weight and high electrical conductivity and thermal conductivity. Buckypaper can replace the copper components in electronic devices and produce light and portable products. In our work, buckypaper can be printed out as an A4 size paper using an inkjet printer. Inkjet printing can be used as an industrial fabrication method in large scale production. We also focus on the composite buckypaper fabricated by vacuum filtration method. The active materials can be attached onto the buckypaper by PVD or simply filtration. We have accomplished the AB₅/buckypaper electrode in nickel metal hydride (NiMH) battery and MoS₂/buckypaper electrode in Lithium-ion battery (LIB). 

RAPS applies the advanced hydrogen generation and storage technologies, combined with a hydrogen fuel cell to meet the electricity consumption in remote areas without CO₂ emission. Our RSAP could find applications in off-grid areas and cooperation is negotiated with local governments in Asia and Africa.

The microgrid integrated with the hydrogen production and low-pressure hydrogen storage technology provides a revolutionary zero-emission, stand-alone RAPS system which is safe and reliable. The project uses green hydrogen for decarbonization in power generation for buildings and industries.

Basic Theory

Our hydrogen storage technology, in conjunction with a PEM electrolyser and PEM fuel cell, is used to guarantee electricity supply when the energy source is intermittent, most typically solar photovoltaic.

The load is supplied directly with PV primary energy, with any excess overload being diverted to the electrolyser to generate hydrogen for storage. Hydrogen will be used by the fuel cell when the load exceeds the available PV power.  

“A hydrogen energy storage system could clearly achieve cost competitiveness for heat and electric energy by use of renewable energy, low-cost hydrogen storage materials, and off-peak cheap electricity at night and stored hydrogen energy in a hydrogen microgrid”.

Table 1.  Specifications of hydrogen microgrid

“Hydrogen Storage and Production Technology for On-Board Systems”, $500,000 (2020-2022) funded by external partner company  

The project started in March 2020.  The project consisted of three parts:

1. Preparation and optimization hydrogen storage system containing high-performance HSMs,
2. Design and development of lightweight hydrogen storage tanks that can withstand 100-150 bar to store HSMs to replace the current high-pressure hydrogen storage technology,
3. Test and optimize the performance of the hydrogen storage system which includes HSMs and hydrogen storage tank in laboratory and actual environment, in order to establish production lines and commercialize the product.

The figure illustrates the hydrogen storage system developed in our group and properties of hydrogen storage materials.

One of the main bottlenecks to realize the hydrogen economy is the effective and safe storage of hydrogen. Current fuel cell vehicles use high-pressure hydrogen storage tanks (700 bar), resulting in high risk, high cost, and high energy consumption. For example, to store 5 Kg of hydrogen in hydrogen fuel cell vehicles (HFCV) to cover a mileage of ~ 500 Km, the cost of each hydrogen storage tank system will be about US$3,000, even under mass production conditions. 

Cost-effective hydrogen storage materials for fuel cell vehicles have been developed by our team, which have excellent hydrogen storage performance. The advantages are:

• Fast kinetics - complete storing or releasing hydrogen within 2-5 minutes compared to recharge time in conventional battery-powered vehicles (2-16h).
• The operating temperature is between 20-150 ºC - ideal for the fuel cell and low energy consumption, as compared to magnesium hydride which has a hydrogen release temperature of up to 300 ºC.
• Hydrogen storage pressure is as low as 150 bar, eliminating the use of high pressure (700 bar) hydrogen storage. 
• High hydrogen storage capacity (4-8 wt.%) resulted from the large surface area of porous structures.
• The cost of raw materials is relatively low. 

Zero-emission hydrogen fuel cell vehicles (HFCVs) are the future to succeed electric vehicles (EV) for the transportation industry, as they are superior in terms of refuelling time and energy storage. Our project is aligned with the NSW Government's future for using zero-emission vehicles transport and alternative fuels by 2056, as the transport sector is currently the second largest and fastest growing emitter in NSW and Australia.  The transition to HFCVs minimizes dependence on imported fuels. Additionally, with the advancement of hydrogen production technology, it is possible to use renewable sources of energy as refilling stations in residential houses.

“Remote Area Power Supply System Based on Hydrogen Energy Storage”, $60,000 (2020-2021) funded by Digital Grid Futures Institute (DGFI)

This project aims to set up a zero-emission Remote Area Power Supply (RAPS) prototype consisting of PV primary energy coupled to an electrolyser, fuel cell and hydrogen storage, to meet the electricity consumption in remote areas. There are many applications in Australia and internationally not served by the main electricity grid that require a reliable standalone power supply. 

The load is supplied directly with PV primary energy, with any excess over load being diverted to the electrolyser to generate hydrogen for storage.  Hydrogen is used by the fuel cell when the load exceeds the available PV power.  The present project is therefore to design a prototype which will integrate the several components discussed above, to simulate the hydrogen charging conditions of using PV and electrolyser, and to study the hydrogen systems coupling to the fuel cell for off-grid power supply.

The main components and specifications of the RAPS system, and the planned schedule are as follows.

“Remote Area Power Supply Systems Based On Hydrogen Energy In Ghana Technology”, (2021) approved by Wassa East District Assembly of Ghana.

The aim of this project is to install a RAPS at three selected villages in the Western Region of Ghana which has a regional electricity access of approximately 84%. These three villages are Akrofi, Ewiadaso and Nyekonakpoe and are about 45 minutes’ drive from Takoradi, the capital of Western Region. A survey of these villages revealed that power is needed for basic activities like charging of phones, watching of television, lighting at classrooms, for businesses like cold storage of fish and farm produce, for the mechanization of local food production and many others.

The project will validate the use of redundant wind or solar energy to produce hydrogen, which in turn will power a facility when the wind or solar energy is not available (e.g., at night, or seasonal times of year). The system can operate locally, independently off the grid for environmentally friendly living. 

This project will demonstrate the feasibility and affordability of the system. A temporary design will concentrate on a unit with a 10kW fuel cell system.