Periodic Reporting for period 1 - SPINMATE (SCALABLE AND SUSTAINABLE PILOT LINE BASED ON INNOVATIVE MANUFACTURING TECHNOLOGIES TOWARDS THE INDUSTRIALISATION OF SOLID-STATE BATTERIES FOR THE AUTOMOTIVE SECTOR)
Reporting period: 2022-08-01 to 2024-01-31
SPINMATE is a Horizon Europe project with 13 partners distributed among 7 countries, together with a mission to demonstrate a scalable, sustainable, safe, and cost-effective digital-driven proof-of-concept pilot line, at a technology readiness level 6, as a first step towards the large-scale manufacturing of generation 4b solid state batteries (SSB) cells and module, to support the electrification of the automotive sector. SPINMATE aims to impact on the battery industry, setting the bases for the manufacturing of the next generation of SSB cells.
SPINMATE innovation relies on the development, optimisation, and upscaling of SSB battery cell components, digitalisation and modelling for SSB cell manufacturing, and finally, the pilot line optimisation and demonstration. SPINMATE will follow a challenging strategy considering the following implementation features: (a) the anode electrode is Li metal, with different mechanical and electrochemical properties than the standard graphite or silicon-based anodes; (b) the solid electrolyte is expected to have a flexibility suitable to be produced as a roll, as Li-ion separators, but the mechanical properties could not be adequate to Z-folding applications, reducing the options for the stacking process to the sole pick-and-place system; and (c) the different mechanical properties of the materials require to re-design the cutting and pick-and-place tools.
The SPINMATE’s Gen 4b SSB cells will create a new industry value chain in Europe towards its commercialisation. This new generation technology will ensure: (1) enhanced energy densities, overcoming current LIB limitations; (2) improved safety in both solutions and workers; (3) increased sustainable mass production; and (4) decreased carbon footprint and cost.
SPINMATE innovation relies on the development, optimisation, and upscaling of SSB battery cell components, digitalisation and modelling for SSB cell manufacturing, and finally, the pilot line optimisation and demonstration. SPINMATE will follow a challenging strategy considering the following implementation features: (a) the anode electrode is Li metal, with different mechanical and electrochemical properties than the standard graphite or silicon-based anodes; (b) the solid electrolyte is expected to have a flexibility suitable to be produced as a roll, as Li-ion separators, but the mechanical properties could not be adequate to Z-folding applications, reducing the options for the stacking process to the sole pick-and-place system; and (c) the different mechanical properties of the materials require to re-design the cutting and pick-and-place tools.
The SPINMATE’s Gen 4b SSB cells will create a new industry value chain in Europe towards its commercialisation. This new generation technology will ensure: (1) enhanced energy densities, overcoming current LIB limitations; (2) improved safety in both solutions and workers; (3) increased sustainable mass production; and (4) decreased carbon footprint and cost.
SPINMATE, a collaborative research project, has set out to develop solid-state batteries with varying scenarios to achieve the ultimate target of 1200Wh/l and 450Wh/kg. The project's technical activities began by setting different scenarios for R&D and pre-industrial levels. These scenarios are based on material and processing development and consider technical constraints raised by the project's partners involved in material development and manufacturing.
The project also develops key components for solid-state batteries, including high-performance gel polymer electrolytes with high ionic conductivity and electrochemical stability. The team optimises the positive electrode by developing an electrode containing carbon additives and a catholyte based on a PVdF polymer used for solid electrolyte development.
Furthermore, the project conducted experiments to enhance the capacity of the cathode material, including testing different calcination gases to mitigate the impact of carbonates formed during the air-based calcination process. The project also collects data for the development of machine learning algorithms.
Lastly, the project determined different specifications to ensure the achievement of its targets, including key unit cell parameters such as volumetric and gravimetric energy densities, which were estimated using a dynamic Python code.
The project also develops key components for solid-state batteries, including high-performance gel polymer electrolytes with high ionic conductivity and electrochemical stability. The team optimises the positive electrode by developing an electrode containing carbon additives and a catholyte based on a PVdF polymer used for solid electrolyte development.
Furthermore, the project conducted experiments to enhance the capacity of the cathode material, including testing different calcination gases to mitigate the impact of carbonates formed during the air-based calcination process. The project also collects data for the development of machine learning algorithms.
Lastly, the project determined different specifications to ensure the achievement of its targets, including key unit cell parameters such as volumetric and gravimetric energy densities, which were estimated using a dynamic Python code.
Cell scenarios setup: properties of different levels of developed materials, such as the density or thickness of polymer electrolyte, cathode active material capacity, and ratio between components in the positive electrode, increase volumetric and gravimetric energy density values.
SSB components: preliminary results in Li||Li symmetric cells show excellent plating/stripping behaviour, indicating high resistance against lithium dendrites growth. Electrolytes membranes have been implemented in full cells with high-voltage cathode materials, showing promising cycling behaviour at room temperature.
Positive electrode assessment: the positive electrode formulation was optimised and characterised in solid-state coin cells (Li/GPE/NMC811), obtaining relevant discharge capacity and high coulombic efficiency values at room temperature.
Calcination atmosphere on NMC811: the use of an oxygen-rich atmosphere during calcination reduced the presence of Ni2+ ions within the NMC811 material, minimizing Li/Ni cation mixing, which negatively affects the material's electrochemical properties. Combined improvements resulted in an average 40% increase in capacity and a capacity retention increase from 60% to 72% during the first 50 cycles (C10). These findings highlight the importance of the chosen calcination atmosphere in optimizing NMC811 properties.
The cell target calculations showed that only a capacity of active material from 190 mAh/g and a minimum thickness of the positive electrode of 100 μm are needed to achieve the target of 450 Wh/kg. Moreover, it showed that a loading of the positive electrode superior to 6 mAh/cm2 leading to a volumetric mass of the positive electrode of 3.5 g/cm3 is thus needed. These values are very challenging targets in terms of processability of the positive electrode and on ionic conductivity too requested for electrolyte because of the tortuosity that need to keep at a high value.
SSB components: preliminary results in Li||Li symmetric cells show excellent plating/stripping behaviour, indicating high resistance against lithium dendrites growth. Electrolytes membranes have been implemented in full cells with high-voltage cathode materials, showing promising cycling behaviour at room temperature.
Positive electrode assessment: the positive electrode formulation was optimised and characterised in solid-state coin cells (Li/GPE/NMC811), obtaining relevant discharge capacity and high coulombic efficiency values at room temperature.
Calcination atmosphere on NMC811: the use of an oxygen-rich atmosphere during calcination reduced the presence of Ni2+ ions within the NMC811 material, minimizing Li/Ni cation mixing, which negatively affects the material's electrochemical properties. Combined improvements resulted in an average 40% increase in capacity and a capacity retention increase from 60% to 72% during the first 50 cycles (C10). These findings highlight the importance of the chosen calcination atmosphere in optimizing NMC811 properties.
The cell target calculations showed that only a capacity of active material from 190 mAh/g and a minimum thickness of the positive electrode of 100 μm are needed to achieve the target of 450 Wh/kg. Moreover, it showed that a loading of the positive electrode superior to 6 mAh/cm2 leading to a volumetric mass of the positive electrode of 3.5 g/cm3 is thus needed. These values are very challenging targets in terms of processability of the positive electrode and on ionic conductivity too requested for electrolyte because of the tortuosity that need to keep at a high value.