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Liquid-Processed Solid-State Li-metal Battery: development of upscale materials, processes and architectures

Periodic Reporting for period 1 - SOLiDIFY (Liquid-Processed Solid-State Li-metal Battery: development of upscale materials, processes and architectures)

Reporting period: 2020-01-01 to 2021-06-30

In the context of fighting against climate changes and global warming, worldwide efforts towards the reduction of CO2 emissions are pushing towards a rapid implementation of electrification of transportation. A steep deployment of battery electric vehicles (BEV) is expected in the coming decade. However, to convince the average consumer to buy electric, and thus enable a reduction of greenhouse gas emission, the electric vehicle should be affordable, safe and with the comfort of large enough driving range and short enough charging time. Those four key requirements are directly linked to the performances of the battery cell, a key component in the Electric Vehicle (EV). Current battery cell technologies are reaching their limits. A main difficulty lies in increasing further the driving range and charging time while maintaining a safe operation of the cell and EV. The SOLiDIFY solid-state battery concept and its unique solid electrolyte component can offer a solution for most shortcomings in battery technology including upscaling and manufacturing at an affordable cost. From a safety point of view, we expect an increase of the safety features of the cells by replacing the conventional liquid flammable electrolyte used in today’s battery by our new thermally stable and non-flammable solid state electrolyte.
The main objectives described in the project proposal are still accurate and extremely challenging as described below:
Today’s electric vehicles are equipped with lithium-ion battery cells than can deliver a little less than 700Wh/L (230Wh/kg) and thus a significant boost in performances is still needed while safety of the cells should remain ensured. A range of 700km is considered a turning point in consumer interest. To reach this driving range, cells of >900Wh/L (>500Wh/kg) will be needed. SOLiDIFY plans to demonstrate two generations of solid-state battery cells reaching 900Wh/L & 1200Wh/L, respectively.
In terms of charging time, customers expect to be able to recharge partially their battery in less than 20min, which we set as a target to recharge our solid-state battery cells.
Finally, while current Li-ion battery cell cost is nowadays on average >125€/kWh, it is a project objective to achieve a manufacturing and material strategy to reach the cost target of < 100€/kWh.Overall the project comprises the development of a manufacturable solid-state battery technology based on a unique liquid-to-solid processed solid electrolyte which is easily impregnated into the electrodes providing multiple advantages towards cell performance and upscale manufacturing both directly in relation with the cost of cell (€/kWh).The larger scope of the SOLiDIFY project entails the development of a novel and potentially European-lead solid-state battery technology and specifically targets upscaling of the processes and cells from demonstrated concepts in the lab to prototypes demonstrated in a pilotline environment.
Since the beginning of the project, the 14 European partners of the Solidify consortium have worked hand in hand towards the development of the various separate components to be integrated together into the first cell prototype expected to be ready at month 24 of the project and having the following intermediate target performances: 900Wh/L, charge in 40 min and having a lifetime >500 cycles.
Over the last 18 months, the different key components have been developed, characterized, and assessed separately:
i) advanced positive electrode (cathode) consisting of active material particles covered with a new thin coating and deposited on a current collector made of a thin aluminum foil (Umicore, Delft-IMP, Fraunhofer, imec, TU-Delft)
ii) advanced solid electrolyte separator sheet being mechanically stable, thin, and conducting the Li+ ion at room temperature (imec, Solvionic)
iii) advanced negative electrode (anode) consisting of protected thin Lithium metal anode (Sidrabe, EMPA, imec, TU-delft)
In addition, initial integration works have taken place under the coordination of imec and Fraunhofer.
A new cell was specifically designed by UHasselt to test solid-state battery cell and components performances as a function of temperature and pressure. Initial results on the newly developed solid-state electrolyte membrane were collected.
In concertation with all partners, the cell specifications, requirements, and testing protocols have been developed by the cell manufacturer and equipment supplier (Leclanché, Solith) and end users (CRF, VDL), respectively. In parallel, the preparation work for the Life Cycle Analysis and cost analysis of new solid-state battery cell has started (Gemmate, leclanché) with a list of data to be collected circulated among all partners.
SOLiDIFY will deliver prototypes of the next generation solid state battery cell demonstrating higher performances (high energy density up to 1200Wh/L, shorter charging time , higher intrinsic safety) than current Li-ion battery cell. A competitive cyclelife (> 1000 cycles) and cost (<100€/kwh) of those new cells are expected.
Advanced materials and assembly processes are expected to be developed and possibly protected as patent applications to strengthen the patent portfolio of the partners and their position in the market.
New models, methodologies and analysis techniques specific for Solid State Battery will be developed as part of the project and will contribute to strengthen the expertise of the partners, strengthening longer-term capabilities and thus fueling the EU modeling ecosystem. In parallel, SOLiDIFY developments will be conducted with full Life Cycle Analysis to ensure that a positive environmental impact is achieved with the developed technologies and materials. Environmental impact assessment of the full life cycle including recycling will be performed.Beside contributing to the preservation of the environment, SOLiDIFY’s vision is to contribute to the European society via the strengthening of the European battery value chain through the development of a competitive and sustainable battery cell in Europe. In addition, the project will enable the development in Europe of a gender-diverse highly qualified work force skilled in the latest battery materials and technologies.