A novel high-throughput extrusion-lamination process for lithium-ion battery manufacture
Lead Research Organisation:
University of Leeds
Department Name: Physics and Astronomy
Abstract
This programme of research is to develop and demonstrate the feasibility of producing a completely new high performance solid state battery suitable for scaling into applications such as electric vehicles, consumer electronics and green energy.
Conventional technology
In the typical conventional Li-ion technology the two electrode foils are kept apart physically by a porous film and the whole battery is enclosed in a rigid container into which the highly flammable liquid electrolyte is injected. This is a batch process of two or more stages.
Most research into Li-ion batteries focuses on the electrodes especially to increase capacity; these are then incorporated in the conventional battery fabrication method. Little research is undertaken into the electrolyte and separators and even less on developing more cost effective fabrication methods and alternatives processing routes.
Advantages of the Leeds technology
The Leeds polymer gel electrolyte and extrusion lamination technology differs from the conventional in that the electrolyte acts as both separator and ion conductor. The highly conducting polymer gel electrolytes possess excellent mechanical toughness and electrochemical stability. The laminated gel electrolyte binds the cell together from within, can be produced on continuous single process, requires no rigid container, and is flexible and formable. Instead of separate components of electrolyte, binder and separator these electrolytes can act as all three.
The development of a thermoreversible gel electrolyte enables melt extrusion of the gel and continuous production of battery cells at high extrusion rates of at least 10m/minute. The elimination of the expensive porous film separator and the high speed extrusion lamination process significantly reduce the cost of battery production.
The programme of research
The Leeds process has been developed and demonstrated for a number of years. It is now poised to take the technology forward to develop the process for the reliable production of multilayer laminates which can be immediately incorporated into batteries.
The development of the process will require a study of the formation of gels at the fast extrusion rates that are required for commercially viable processing.
Future commercial developments
This programme will demonstrate that the technology can produce mainstream cost effective Li-ion batteries with enhanced safety and high specific capacity.
Conventional technology
In the typical conventional Li-ion technology the two electrode foils are kept apart physically by a porous film and the whole battery is enclosed in a rigid container into which the highly flammable liquid electrolyte is injected. This is a batch process of two or more stages.
Most research into Li-ion batteries focuses on the electrodes especially to increase capacity; these are then incorporated in the conventional battery fabrication method. Little research is undertaken into the electrolyte and separators and even less on developing more cost effective fabrication methods and alternatives processing routes.
Advantages of the Leeds technology
The Leeds polymer gel electrolyte and extrusion lamination technology differs from the conventional in that the electrolyte acts as both separator and ion conductor. The highly conducting polymer gel electrolytes possess excellent mechanical toughness and electrochemical stability. The laminated gel electrolyte binds the cell together from within, can be produced on continuous single process, requires no rigid container, and is flexible and formable. Instead of separate components of electrolyte, binder and separator these electrolytes can act as all three.
The development of a thermoreversible gel electrolyte enables melt extrusion of the gel and continuous production of battery cells at high extrusion rates of at least 10m/minute. The elimination of the expensive porous film separator and the high speed extrusion lamination process significantly reduce the cost of battery production.
The programme of research
The Leeds process has been developed and demonstrated for a number of years. It is now poised to take the technology forward to develop the process for the reliable production of multilayer laminates which can be immediately incorporated into batteries.
The development of the process will require a study of the formation of gels at the fast extrusion rates that are required for commercially viable processing.
Future commercial developments
This programme will demonstrate that the technology can produce mainstream cost effective Li-ion batteries with enhanced safety and high specific capacity.
Planned Impact
Technological Impact
Lithium-ion batteries have already become the power source of choice for portable electronic devices such as laptops and mobile phones owing to their superior performance when compared with alternative rechargeable battery systems. Their use is widely predicted to grow substantially in the short to medium term in new areas such as automotive propulsion and energy storage systems.
Whilst there is pressure to achieve better power performance, essentially via improvements in anode and cathode materials, it is also crucial to address both cost and safety issues and solutions on these fronts are essential before lithium ion battery technology can surge ahead through further displacement of 'conventional' batteries in the big new applications. For example, hybrid and fully electric vehicles are currently in the high price bracket due to the high cost of safe battery units and instances such as the US Airline Pilots Association request to ban the transportation of lithium batteries on commercial aircraft is an indication of very real concerns over safety.
The Leeds technology offers unique solutions to these problems, as well as being adaptable to most lithium-ion battery configurations. Benefits include the use of much safer chemistry, simpler construction, single-stage continuous manufacture, low capital cost, and flexibility in battery forms.
Small scale prototypes, effectively hand-made, using a variety of electrode materials, have demonstrated the efficacy of the Leeds polymer gel electrolytes and the practicality of the extrusion/lamination manufacturing process. More recently work with latest generation high capacity electrode materials has demonstrated unprecedented specific energy densities in cells produced using polymer gel electrolytes produced in Leeds.
With a greater understanding of the behaviour of the gel extrusion process, combined with tighter control of the lamination procedure, we foresee this technology as being readily scalable to large cell formats with the opportunity for high speed, highly automated production. Further, with better control of the processes involved yet thinner cells with lower internal resistance and higher specific energy will be the result. Once proven at the 'entry' level through this project, the technology will be capable of cost effective and safe larger scale formats (electric vehicles and power storage applications).
UK Economic Opportunities
The UK no longer has a prominent position in the global battery manufacturing industry and has lost its commercial production capability at present - all batteries are now imported. The rising demand across all application areas, the need to find safe, low-cost alternatives and the transition to UK-based technologies has the potential for the UK to re-establish its economic competitiveness by developing a new advanced manufacturing base.
Matching Leeds inventions from previous R&D with a UK industrial partner for prototype development and testing, the results of this project will potentially result in a world-leading solid state energy storage device. Running alongside this project it is a priority to find the partners and investors to create a UK based manufacturing company, allowing for wealth creation (and import substitution) in what is already becoming a multi-billion pound market.
Carbon Reduction
Combating global warming and targeting carbon reductions, there is strong political, legal and consumer pressure on vehicle manufacturers to bring out new hybrid vehicles that are more fuel efficient. Figures suggest 23 - 29% carbon saving from plug-in hybrids currently and the potential for vehicles to be zero-carbon. Also more efficient energy storage solutions are being sought, either for battery packs for a wide range of uses, or as backup to power generation systems. Energy storage rather than loss or wastage has obvious advantages.
Lithium-ion batteries have already become the power source of choice for portable electronic devices such as laptops and mobile phones owing to their superior performance when compared with alternative rechargeable battery systems. Their use is widely predicted to grow substantially in the short to medium term in new areas such as automotive propulsion and energy storage systems.
Whilst there is pressure to achieve better power performance, essentially via improvements in anode and cathode materials, it is also crucial to address both cost and safety issues and solutions on these fronts are essential before lithium ion battery technology can surge ahead through further displacement of 'conventional' batteries in the big new applications. For example, hybrid and fully electric vehicles are currently in the high price bracket due to the high cost of safe battery units and instances such as the US Airline Pilots Association request to ban the transportation of lithium batteries on commercial aircraft is an indication of very real concerns over safety.
The Leeds technology offers unique solutions to these problems, as well as being adaptable to most lithium-ion battery configurations. Benefits include the use of much safer chemistry, simpler construction, single-stage continuous manufacture, low capital cost, and flexibility in battery forms.
Small scale prototypes, effectively hand-made, using a variety of electrode materials, have demonstrated the efficacy of the Leeds polymer gel electrolytes and the practicality of the extrusion/lamination manufacturing process. More recently work with latest generation high capacity electrode materials has demonstrated unprecedented specific energy densities in cells produced using polymer gel electrolytes produced in Leeds.
With a greater understanding of the behaviour of the gel extrusion process, combined with tighter control of the lamination procedure, we foresee this technology as being readily scalable to large cell formats with the opportunity for high speed, highly automated production. Further, with better control of the processes involved yet thinner cells with lower internal resistance and higher specific energy will be the result. Once proven at the 'entry' level through this project, the technology will be capable of cost effective and safe larger scale formats (electric vehicles and power storage applications).
UK Economic Opportunities
The UK no longer has a prominent position in the global battery manufacturing industry and has lost its commercial production capability at present - all batteries are now imported. The rising demand across all application areas, the need to find safe, low-cost alternatives and the transition to UK-based technologies has the potential for the UK to re-establish its economic competitiveness by developing a new advanced manufacturing base.
Matching Leeds inventions from previous R&D with a UK industrial partner for prototype development and testing, the results of this project will potentially result in a world-leading solid state energy storage device. Running alongside this project it is a priority to find the partners and investors to create a UK based manufacturing company, allowing for wealth creation (and import substitution) in what is already becoming a multi-billion pound market.
Carbon Reduction
Combating global warming and targeting carbon reductions, there is strong political, legal and consumer pressure on vehicle manufacturers to bring out new hybrid vehicles that are more fuel efficient. Figures suggest 23 - 29% carbon saving from plug-in hybrids currently and the potential for vehicles to be zero-carbon. Also more efficient energy storage solutions are being sought, either for battery packs for a wide range of uses, or as backup to power generation systems. Energy storage rather than loss or wastage has obvious advantages.
Organisations
Publications
| Description | (i) A cost-effective high-throughput extrusion-lamination process has been developed for the continuous in-line production of lithium-ion batteries. (ii) The research has demonstrated that multiple laminates using double and single sided electrode foils can be made with this process. |
| Exploitation Route | The findings are being used to advance programmes for the further development of this technology. |
| Sectors | Aerospace, Defence and Marine,Energy,Manufacturing, including Industrial Biotechology,Transport |
| Description | A novel high-throughput extrusion-lamination process for lithium-ion battery manufacture has been developed. This research programme has demonstrated the potential for developing a process for the continuous in-line production of lithium-ion battery packs by a method different from that currently used within the industry. |
| Sector | Cultural |
| Title | Improved extrusion-lamination process |
| Description | An improved process for the extrusion-lamination of lithium ion batteries has been developed.This improved process allows for the controlled production of laminates with thin electrolyte layers (~25 microns) at high speed. A wider extrusion die, and wider feed, lamination and haul off rollers, enables laminates with electrode foils of up to 160 mm to be laminated at high speed. Additional experiments have successfully demonstrated that multiple laminates using double and single sided electrode foils can be made with this process. This has demonstrated the potential for developing the process for the continuous fabrication of multiple layer battery packs. |
| Type Of Technology | Systems, Materials & Instrumental Engineering |
| Title | New horizontal lamination facility |
| Description | A new horizontal lamination facility has been developed for the manufacture of lithium ion batteries. The facility centres around a temperature controlled belt press and temperature and pressure controlled lamination rollers. It enables the controlled layering of the polymer gel electrolyte onto the electrodes with greater control of the electrode foils and gel prior to lamination in the nip (compared to the previous vertical lamination facility). This allows for the controlled production of laminates with thin electrolyte layers (~25 microns) using wider electrode foils (up to 160 mm) at higher speeds (to 10 m/min). This facility has the potential for post lamination processing allowing for the in-line production of completed battery packs. A large dry chamber, typically attaining -50°C dewpoint, has been built to house the facility. |
| Type Of Technology | New/Improved Technique/Technology |