Periodic Reporting for period 1 - RESILEX (Resilient Enhancement for the Silicon Industry Leveraging the European matriX)
Periodo di rendicontazione: 2022-06-01 al 2023-11-30
Silicon is one of the few critical raw materials used in most of the strategic renewable energy applications: improving its value chain is of major importance for the EU’s resilience, as this material is used in several key sectors, from batteries to PV & ICT, and it’s not easily replayable without serious loss of end performance or increase of cost.
Today, only 32% of the Silicon used in Europe is produced within the EU, in a global market dominated by China. The core activity of RESiLEX is to strengthen each part of the Silicon value chain, through the technological improvement of all its processes, from the extraction and transformation of the raw material up to the optimization and recycling of PV modules, and the reuse of Silicon for Lion Batteries. RESiLEX targets the sourcing and reuse of other critical raw materials for the green transition as well as to minimise their use in newly designed PV panels.
The project goal is to demonstrate several industry-driven innovative solutions (TRL6-7), aiming at sustainable and resilient critical raw material value chains in Europe.
Today, only 32% of the Silicon used in Europe is produced within the EU, in a global market dominated by China. The core activity of RESiLEX is to strengthen each part of the Silicon value chain, through the technological improvement of all its processes, from the extraction and transformation of the raw material up to the optimization and recycling of PV modules, and the reuse of Silicon for Lion Batteries. RESiLEX targets the sourcing and reuse of other critical raw materials for the green transition as well as to minimise their use in newly designed PV panels.
The project goal is to demonstrate several industry-driven innovative solutions (TRL6-7), aiming at sustainable and resilient critical raw material value chains in Europe.
The main achievements for each activity of the project are:
1/ Recovery of critical raw materials from mining wastes and wastewater: Partner CETAQUA first characterized the samples of acidic and solid waters from the mining demonstration site to determine which points are of greater interest to recover critical materials. In parallel, we designed two treatment trains to recover valuable metals from wastewater and mining waste, respectively. The first will be located at CETAQUA facilities and consists of a non-ferrous metal recovery unit followed by an adsorption module with a final crystallizer. The second will be located at THARSIS facilities and consists of a thermal waste valorization unit. These treatment trains are currently under construction.
2/ Sustainable silicon production: RESILEX aims to address the laboratory scale verification of silicon recycling route and sustainable silicon production demonstration. NTNU is working on a circular process to produce high purity silicon through aluminothermic reduction of quartz fine as an alternative to carbothermic reduction followed by refining of the produced metals utilizing as raw materials Si-kerf, sculls, slag, and silicon alloy. NTNU optimized the laboratory and medium-scale production and refining processes and successfully demonstrated it at a 100 kg scale.
3/ Sustainable, eco-designed solar cells & modules: In these activities and lab tests, there has been remarkable headway in reducing the usage of indium within solar cells, largely attributable to the reduction in thickness of indium tin oxide layers. This has contributed to enhancing the sustainability of solar cell technologies while maintaining high efficiency.
Second, the project has already made substantial strides in minimizing the utilization of silver in solar cells through the development of silver-copper-coated pastes and the implementation of a copper plating process. These innovative approaches have made it possible to reduce dependence on silver, a precious and costly resource, without compromising the performance of the solar cells.
Finally, project partners have undertaken an extensive, and still ongoing, screening of available EU providers for bio-sourced materials, polymers, and composites required for the front and back-sheet as well as for the encapsulants. This meticulous assessment has been complemented by an exhaustive literature review, yielding detailed insights into the suitability, sustainability, and performance characteristics of these materials to build PV modules.
4/ Silicon recycling from PV modules: In RESILEX, silicon material out of Silicon cells recovered from PV panels (provided by Recma and ENVIE2E) will be used to make batteries and/or new Silicon wafers. Achieving the required grades imposes the recovered silicon to be cleaned (acid leaching under pressure at 60°C) from all impurities, like Aluminium and Iron. Indeed, batteries manufacturers require a Silicon purity >99% and PV wafers require a purity > 99.999999%. Preliminary tests achieved by the GeMMe laboratory (University of Liège) demonstrate the possibility to obtain a Silicon purity of 99.5%. The first tests of battery manufacturing using such purified materials were conclusive. New separating techniques are under investigation, to recover as much Silicon as possible.
5/ Development of high-efficiency Si composite for Li-ion batteries: Partner CLEANCARB is working on the specifications of the battery cells that the project will develop. GREEnMat at ULiege showed that high purity of Silicon can be recovered from non-encapsulated PV solar cells through leaching process. The obtained pure Silicon was successfully nano-sized and integrated in the spray drying process along with conductive additives and polymer binders leading to Si/C composites with controlled morphology and particle size. The prepared composites were used as anode active materials for Li-ion batteries (LIBs). The results for half-cell configuration tests demonstrate specific capacities as high as 1200 mAh.g−1, a promising result for the next work on full cell tests using conventional cathode materials and scale-up production of greener quality, inexpensive anode-based materials.
6/ Multi-faceted Impact assessment & EU policy recommendations: Social-LCA approach has been implemented in this regard based on ISO standard 14040/14044 in which the European companies active in PV modules have been identified, contacted and interviewed. The relevant social sub-categories to PV industry have been shortlisted based on these sets of interviews and the next round interviews have been designed. Regarding the Life Cycle Cost analysis of the panels that the project will develop, CEA started by defining the reference technology for the different components in the value chain of the PV module (polysilicon, wafer, cell, module).
1/ Recovery of critical raw materials from mining wastes and wastewater: Partner CETAQUA first characterized the samples of acidic and solid waters from the mining demonstration site to determine which points are of greater interest to recover critical materials. In parallel, we designed two treatment trains to recover valuable metals from wastewater and mining waste, respectively. The first will be located at CETAQUA facilities and consists of a non-ferrous metal recovery unit followed by an adsorption module with a final crystallizer. The second will be located at THARSIS facilities and consists of a thermal waste valorization unit. These treatment trains are currently under construction.
2/ Sustainable silicon production: RESILEX aims to address the laboratory scale verification of silicon recycling route and sustainable silicon production demonstration. NTNU is working on a circular process to produce high purity silicon through aluminothermic reduction of quartz fine as an alternative to carbothermic reduction followed by refining of the produced metals utilizing as raw materials Si-kerf, sculls, slag, and silicon alloy. NTNU optimized the laboratory and medium-scale production and refining processes and successfully demonstrated it at a 100 kg scale.
3/ Sustainable, eco-designed solar cells & modules: In these activities and lab tests, there has been remarkable headway in reducing the usage of indium within solar cells, largely attributable to the reduction in thickness of indium tin oxide layers. This has contributed to enhancing the sustainability of solar cell technologies while maintaining high efficiency.
Second, the project has already made substantial strides in minimizing the utilization of silver in solar cells through the development of silver-copper-coated pastes and the implementation of a copper plating process. These innovative approaches have made it possible to reduce dependence on silver, a precious and costly resource, without compromising the performance of the solar cells.
Finally, project partners have undertaken an extensive, and still ongoing, screening of available EU providers for bio-sourced materials, polymers, and composites required for the front and back-sheet as well as for the encapsulants. This meticulous assessment has been complemented by an exhaustive literature review, yielding detailed insights into the suitability, sustainability, and performance characteristics of these materials to build PV modules.
4/ Silicon recycling from PV modules: In RESILEX, silicon material out of Silicon cells recovered from PV panels (provided by Recma and ENVIE2E) will be used to make batteries and/or new Silicon wafers. Achieving the required grades imposes the recovered silicon to be cleaned (acid leaching under pressure at 60°C) from all impurities, like Aluminium and Iron. Indeed, batteries manufacturers require a Silicon purity >99% and PV wafers require a purity > 99.999999%. Preliminary tests achieved by the GeMMe laboratory (University of Liège) demonstrate the possibility to obtain a Silicon purity of 99.5%. The first tests of battery manufacturing using such purified materials were conclusive. New separating techniques are under investigation, to recover as much Silicon as possible.
5/ Development of high-efficiency Si composite for Li-ion batteries: Partner CLEANCARB is working on the specifications of the battery cells that the project will develop. GREEnMat at ULiege showed that high purity of Silicon can be recovered from non-encapsulated PV solar cells through leaching process. The obtained pure Silicon was successfully nano-sized and integrated in the spray drying process along with conductive additives and polymer binders leading to Si/C composites with controlled morphology and particle size. The prepared composites were used as anode active materials for Li-ion batteries (LIBs). The results for half-cell configuration tests demonstrate specific capacities as high as 1200 mAh.g−1, a promising result for the next work on full cell tests using conventional cathode materials and scale-up production of greener quality, inexpensive anode-based materials.
6/ Multi-faceted Impact assessment & EU policy recommendations: Social-LCA approach has been implemented in this regard based on ISO standard 14040/14044 in which the European companies active in PV modules have been identified, contacted and interviewed. The relevant social sub-categories to PV industry have been shortlisted based on these sets of interviews and the next round interviews have been designed. Regarding the Life Cycle Cost analysis of the panels that the project will develop, CEA started by defining the reference technology for the different components in the value chain of the PV module (polysilicon, wafer, cell, module).
The expected results and potential impacts are:
1/ Recovery Treatment train demonstrated at Tharsis mine and replicated in 5 other Europan mines.
2/ Demonstration and development of a carbon-free sustainable process in Norway for producing Silicon and Silicon alloys suitable for solar applications.
3/ Demonstration of eco-designed solar cells (such as CRM-free solar cells and Silicon wafers from revalorized Silicon wastes)
4/ Scaled-up PV dismantling line in Toulouse by Comet, Recma and Envie2E, reducing the EU’s demand for primary materials and hence lessening its reliance on imported CRM.
5/ Scaled-up production of nanopowders for battery applications to replace graphene anode in Li-ion batteries by high-energy density Silicon-carbon composite anodes.
6/ EU policy recommendations through an open-source platform, eg. promoting the Integration of Silicon to the Carbon Border Adjustment Mechanism (CBAM).
1/ Recovery Treatment train demonstrated at Tharsis mine and replicated in 5 other Europan mines.
2/ Demonstration and development of a carbon-free sustainable process in Norway for producing Silicon and Silicon alloys suitable for solar applications.
3/ Demonstration of eco-designed solar cells (such as CRM-free solar cells and Silicon wafers from revalorized Silicon wastes)
4/ Scaled-up PV dismantling line in Toulouse by Comet, Recma and Envie2E, reducing the EU’s demand for primary materials and hence lessening its reliance on imported CRM.
5/ Scaled-up production of nanopowders for battery applications to replace graphene anode in Li-ion batteries by high-energy density Silicon-carbon composite anodes.
6/ EU policy recommendations through an open-source platform, eg. promoting the Integration of Silicon to the Carbon Border Adjustment Mechanism (CBAM).