Borate compounds are the proper candidates as electrolyte additives, by improving the performance, the stability and other properties, such as safety of the Li-ion cells. In addition, this is the most effective and economic method to suppress the capacity fading and improve the cycling performance of Lithium Nickel Cobalt Manganese Oxide (NMC). Moreover, the additives substantially decrease the decomposition reactions of the anode and cathode, leading to a reduced amount of gas swelling, after the formation process.
The main objective of this project is to elaborate and develop a scientific and technical approach for borate-based additives for the existing electrolyte systems, in a sustainable way to TRL 4, that function at the high working voltages of NMC- cathode material. Thus, BeLion will develop and optimize Li-ion pouch cells by combining innovation with improvements beyond state-of-the-art via safe electrolyte systems. Tris(trimethylsilyl)borate will be synthesized and used as additive in order to formulate different electrolyte systems. The effects of the borate additives on the NMC electrode will be investigated via a combination of electrochemical, structural and morphological characterization.
Project team
Project leader: PhD Chem. Spinu Zaulet Adnana; https://orcid.org/0000-0002-0094-3813
National Research and Development Institute for Cryogenics and Isotopic Technologies – ICSI Rm. Valcea; ICSI Energy
Mentor: Prof. PhD. Eng. Vaireanu Danut Ionel; https://orcid.org/0000-0003-2737-2990
Faculty of Applied Chemistry and Materials Science, Politehnica National University for Science and Technology, Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry
Objectives
Based on the above state-of-the art, the Project Leader aims to elaborate and develop a scientific and technical approach for borate-based additive for the existing electrolyte systems, in a sustainable way to TRL 4, that function at the high working voltages of NMC- Lithium Nickel Cobalt Manganese Oxide (NMC) cathode material. BeLion will develop and optimize Li-ion pouch cells by combining innovation with improvements beyond state-of-the-art via safe electrolyte systems. This is essential to achieve the increased energy density promised by the electrode material developments in safe batteries with sufficient lifetime for exploitation in the market.
Thus, the novelty of this proposal is based on the synthesis of borate-based additive for the existing electrolyte NMC systems and the need to demonstrate the borate based additive role in LIBs electrolyte system. According to literature, the electrolyte stability must be improved to avoid the flame ability and gas swelling of lithium batteries. Thus, the Project Leader previous experience in the boron clusters synthesis is once more a motivation to use also borate compounds that will enhance not only the high-temperature cycling performance, but also the rate capabilities of high voltage cathodes by the modification of the surface on the electrodes and the inhibition of further electrolyte decomposition and transition metal dissolution. Within the BeLion project, the Project Leader will offer also, its expertise with regard to the manufacturing and testing using R&D infrastructure for lithium-based batteries, complying with the international standards. Also, considerable expertise was acquired over the time in the field of electrodes manufacturing, characterization, cells evaluations, and performances evaluations and this can be successfully used as a cornerstone for a jump-start in the allocated practical activities.
This approach will represent a premier at national level by using such flame retarding additives for improvement of LIBs safety and performance. In the context of the scientific approach detailed above, the main research objectives (O) of the proposed project are:
O1: Synthesis of Tris(trimethylsilyl)borate as an electrolyte additive for high-voltage lithium-ion batteries using NMC cathode;
Actions towards this objective:
– Synthesis and characterization of high-purity Tris(trimethylsilyl)borate by reaction of trimethylacetoxysilane with boric acid;
O2: Electrodes manufacturing and pouch cell assembly using NMC based cathode and graphite based anode;
Actions towards this objective:
– The electrodes manufacture will be performed applying the R&D pilot scale electrode production processing equipment in order to reach relevant TRL 4;
– BeLion prototype cells (large pouch cells: ICSI’s format), in a capacity range from 1 Ah up to 5 Ah will be performed applying the R&D pilot scale cell assembly;
O3: New additives for the existing electrolytes;
Actions towards this objective:
– Formulate and validate electrolytes based on mixed salt compositions (content of LiTFSI or LiTSI and LiPF6) with carbonate solvents with the innovation on use of concentrated and mixed salts, fire retardant and high voltage additives (Tris(trimethylsilyl)borate) for cells validation.
O4: Electrochemical characterization of the additivated electrolytes;
Actions towards this objective:
– Investigation of electrolyte/electrode interface using lithium salt electrolytes formulated in conventional solvents. Comparison of cycling stability of lithium salt-containing electrolytes will be performed;
– Electrochemical characterization (CV, EIS, OCP) during formation cycle, physico-chemical changes at the electrodes side and gas evolution.
Expected results
• Synthesis and characterization of high-purity Tris(trimethylsilyl)borate (TMSB) as an electrolyte additive for lithium-ion batteries using NMC cathode by reaction of trimethylacetoxysilane with boric acid;
• Formulation and scale-up on electrode manufacturing;
• Electrolyte formulation based on mixed salt compositions (content of lithium bis(trifluoromethanesulfonyl)imide – LiTFSI or LiTSI and LiPF6) with carbonate solvents, mixed salts, and high voltage additives (Tris(trimethylsilyl)borate);
• BeLion prototype cells (large pouch cells: ICSI’s format), assembly using the R&D pilot line – 10 prototype cells;
• Electrochemical characterization of LiTFSI/LiTSI/LiPF6 electrolytes containing TMSB additive. Investigation of electrolyte/electrode interface using lithium salt electrolytes formulated in conventional solvents. Electrochemical characterization (CV, EIS, OCP) during formation cycle, cycling stability and gas evolution will be performed.
Budget
Total budget: 239.950 RON
Budget allocation by stages (in RON):
• Stage 1: Synthesis of Tris(trimethylsilyl)borate as an electrolyte additive.
Total budget: 70.000 Lei
• Stage 2: Pouch cells manufacturing and testing (part I).
Total budget: 99 000 Lei.
• Stage 3: Pouch cells manufacturing and testing (part II).
Total budget: 70 950 Lei.
Dissemination
Scientific manifestations:
-
Adnana Spinu-Zaulet, Mihaela Buga, Cosmin Ungureanu, Danut Ionel Vaireanu „Boron based additives for electrolytes in lithium-ion batteries” E-MRS Spring Meeting 2021, May 31st – June 3rd 2021, pre-recorded poster presentation, https://www.european-mrs.com/2d-materials-energy-applications-emrs#
-
Adnana Spinu-Zaulet, Mihaela Buga, Cosmin Ungureanu, Danut Ionel Vaireanu „Tris(trimethylsilyl) borate as an Efficient Electrolyte Additive for Nickel-Rich NMC811 Cathode in Lithium-Ion Battery” XXIIIrd International Conference – New Cryogenic and Isotope Technologies for Energy and Environment – EnergEn 2021, Baile Govora, Romania, October 26-29, 2021, poster presentation.
https://www.icsi.ro/energen2021/programme
-
Danut-Ionel Vaireanu, Florin – Mihai Benga, Ioana-Alina Ciobotaru, Adnana Alina Spinu-Zaulet, „Myths and Reality in Using and Misusing Lithium Based Rechargeable Batteries”, XXIIIrd International Conference – New Cryogenic and Isotope Technologies for Energy and Environment – EnergEn 2021, Baile Govora, Romania, October 26-29, 2021, oral presentation. https://www.icsi.ro/energen2021/programme
-
Adnana Spinu-Zaulet, Mihaela Buga, Cosmin Ungureanu, Danut Ionel Vaireanu, „Enhanced electrochemical performance of NMC811/Graphite lithium-ion cells by adding tris(trimethylsilyl)borate as electrolyte additive, E-MRS Fall Meeting 2023, September 18-21, 2023, Warsaw, Poland, poster presentation, https://www.european-mrs.com/meetings/2023-fall-meeting
-
Adnana Spinu-Zaulet, Alexandru Rizoiu, Cosmin Ungureanu, Mihaela Buga, Danut Ionel Vaireanu, „Tris(trimethylsilyl) borate as highly effective electrolyte additive for NMC811/Graphite lithium-ion cells”, HYDRA International Workshop, June 28 – 29, 2023, Trondheim, Norway-Banksalen, poster presentation, https://www.sintef.no/en/events/archive/2023/hydra-international-workshop-2023/
Patent application
A/00503/14.09.2023 – Celule electrochimice Li-ion de tip punguță cu catod pe bază de oxizi stratificați bogați în nichel folosiți în conjuncție cu sisteme de electroliți cu grad ridicat de siguranță termică, inventors: SPÎNU-ZĂULEȚ Adnana Alina, BUGA Mihaela-Ramona, UNGUREANU Cosmin Giorgian, CHIȚU Alin Mugurel, VĂIREANU Dănuț-Ionel, VARLAM Mihai.
© 2020 I.C.S.I. Rm. Vâlcea
