Lithium-ion battery with silicon anode, nickel-rich cathode and in-cell sensor for electric vehicles

Project Information

SeNSE

Grant agreement ID: 875548

DOI

10.3030/875548

Project closed

EC signature date 14 November 2019

Start date 1 February 2020

End date 31 January 2024

Funded under

• SOCIETAL CHALLENGES - Smart, Green And Integrated Transport

Total cost

€ 10 251 678,75

EU contribution

€ 10 251 678,75

Coordinated by

EIDGENOSSISCHE MATERIALPRUFUNGS- UND FORSCHUNGSANSTALT
Switzerland

Periodic Reporting for period 3 - SeNSE (Lithium-ion battery with silicon anode, nickel-rich cathode and in-cell sensor for electric vehicles)

Reporting period: 2023-02-01 to 2024-01-31

Summary of the context and overall objectives of the project

The SeNSE project aimed at enabling a competitive next-generation lithium-ion battery technology for electric vehicles, extending driving range, improving cycling stability, and enabling fast charging, thereby supporting the transition to electric mobility. The scalability of the SeNSE battery technology was demonstrated successfully through the fabrication of 12 Ah SeNSE prototype pouch cells with a silicon-graphite composite anode and a nickel-rich layered oxide cathode. These cells reached the energy density target of ≥750 Wh/L on cell level, the fast charging target of 2.5C and the sustainability target of reducing the ratio of critical cobalt to nickel in the cathode to below 10%. Cells without silicon are on track to reach 80% capacity retention after 2000 deep cycles. Cells with silicon did not reach this target due to challenges associated with the stability of silicon. However, silicon pre-lithiation was demonstrated to be an effective approach to increase cycle life.

12 Ah SeNSE prototype pouch cells were integrated into a modular 0.5 kWh SeNSE battery module coupled to an adaptive cooling system. Cooling is controlled by a smart battery management system reading and analyzing data in real time from the in-cell sensor arrays integrated into the 12 Ah SeNSE prototype pouch cells. The smart battery module demonstrates the SeNSE battery technology in an industrially relevant environment reaching technology readiness level 5-6. The cost projection for the SeNSE battery technology showed that the cost target of 90 Euro/kWh on pack level can be met for large gigafactories when anode materials with a high silicon content become available at a price comparable to that of graphite.

A highlight of the project was the collaboration with the other three projects funded through the same call, COBRA, Hydra, and 3beLiEVe, in a cluster that organized joint dissemination activities, such as a joint newsletter, joint workshops, and joint conference sessions.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

Anode development: An innovative cost-effective method for the synthesis of silicon-graphite composite anode materials with a silicon content of >10% was developed and materials were characterized electrochemically in half- and full-cell configuration. The production of selected silicon-graphite composite anode materials was upscaled to industrial pilot scale to enable their integration into 12 Ah SeNSE prototype pouch cells. Silicon pre-lithiation was shown to extend cycle life by a factor of 2 [1-3].

Electrolyte development: Several strategies to improve the safety of liquid electrolytes such as the addition of ionic liquids or flame retardants were explored and electrolyte formulations were identified that combine high lithium-ion conductivity and low flammability.[4,5] In addition, several film-forming additives were synthesized and electrolyte formulations containing these additives were identified that improve the cycling stability of full cells with (silicon)-graphite anode and a nickel-rich layered oxide cathode.[6,7] Furthermore, the synthesis of multiple additives developed in the SeNSE project was upscaled to industrial pilot scale.

Cathode development: Nickel-rich layered oxide cathode materials with a cobalt to nickel ratio <10% were synthesized and characterized in terms of structure, morphology, and electrochemical properties. To improve cycling stability, several doping and protective coating strategies were explored and modification strategies were identified that significantly improve the cycling stability.[8-11] A selected coated nickel-rich layered oxide cathode material was upscaled to pilot scale to enable integration into 12 Ah SeNSE prototype pouch cells.

Electrode development: As an alternative to traditional electrode manufacturing processes employing toxic solvents, aqueous electrode manufacturing processes were developed and scaled for the negative and positive electrode including also an aqueous process for the protective coating of the nickel-rich layered oxide cathode materials. [12,13] The use of an alternative conductive additive for the positive electrode was also explored and beneficial effects in terms of thermal and electrical properties were identified.

Cell development: In-cell sensor arrays measuring temperature and potential were successfully developed and integrated into 12 Ah SeNSE prototype pouch cells. Several reference electrode materials were compared with titanium dioxide-based electrodes delivering the most reliable result.[14,15]

Module development: A modular 0.5 kWh SeNSE smart battery module incorporating twelve instrumented 12 Ah SeNSE prototype pouch cells was developed. The in-cell sensor arrays were key to reach the fast-charging target of 2.5C by providing the battery management system with real-time data enabling adaptive cooling strategies.
While the COVID-19 pandemic effected the project and certain tasks had to be reallocated to other members of the consortium including new members, delays could be compensated in the second half of the project.

References:
[1] Adv. Energy Mater. 2021, 11, 2100925.
[2] Adv. Sci. 2022, 9, 2201742.
[3] Adv. Energy Sustainability Res. 2024, 5, 2300177.
[4] Electrochim. Acta 2022, 427, 140867.
[5] Batteries Supercaps 2023, 6. e202300220.
[6] ChemElectroChem 2021, 8, 972.
[7] J. Power Sources 2023, 557, 232570.
[8] ChemSusChem 2021, 15, e202102220.
[9] Adv. Energy Mater. 2022, 12, 2103045.
[10] Batteries 2023, 9, 245.
[11] Electrochim. Acta 2023, 462, 142758.
[12] ChemSusChem 2022, 15, e202200401.
[13] ChemSusChem 2022, 16, e202202161.
[14] Energy Technol. 2021, 9, 2100602.
[15] Energy Technol. 2022, 10, 202200248.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

The SeNSE project has generated significant impact by advancing generation 3b lithium-ion battery technology, equipping SeNSE industry partners with competences, expertise, and scalable technological innovations. Project advances are so far documented in 16 scientific publications published in peer-reviewed scientific journals, 4 patent applications, and more than 30 conference contributions. All scientific publications were published through open access publishing.

The technologies developed in the SeNSE project benefited the industrial partners of the project as reflected, e.g. by the successful completion of a recent series A funding round by a project partner to establish a pilot production. Another project partner recently initiated the construction of a pilot production facility with an annual production capacity of 30 tons per year for their advanced material that was successfully validated in the SeNSE project. During the 4 years of the SeNSE project, more than 15 PhD students and postdocs were trained on the development of battery materials, electrodes, sensors, cells, battery management systems, or module assembly through their work in the SeNSE project contributing to alleviate the current shortage in skilled work force in Europe, which is particularly acute in the battery industry. Most former members of the SeNSE project continue to contribute to strengthen the European battery industry thereby creating a lasting legacy for the SeNSE project.

12 Ah instrumented SeNSE prototype pouch cells