ORALS

SESSION: BatteryFriAM-R11	6th Intl. Symp. on Sustainable Secondary Battery Manufacturing and Recycling
Fri Oct, 25 2019 / Room: Coralino
Session Chairs: Katerina Aifantis; Rumen Tomov; Session Monitor: TBA

12:35: [BatteryFriAM04]
Novel Carbon - Ultrafine Silicon Composite Anode for High-Performance Lithium-Ion Batteries
Dmitry Yarmolich¹ ; Dzianis Yarmolich² ; Yaroslav Odarchenko³ ; Carmen Murphy⁴ ; Enrico Petrucco⁴ ; Vasant Kumar⁵ ; Rumen Tomov⁵ ; ¹Plasma App Ltd, OX11 0QX, United Kingdom; ²Plasma App Ltd, Oxford , OX11 0QX, United Kingdom; ³Plasma App Ltd, Oxford OX11 0QX, United Kingdom; ⁴Johnson Matthey Battery Materials, Reading RG4 9NH, United Kingdom; ⁵University of Cambridge, Cambridge, United Kingdom;
Paper Id: 352 [Abstract]

Silicon (Si) has been widely considered as potential high capacity anode material in Li-ion batteries due to its desirable properties: (i) high theoretical specific capacity (1672 mA h g-1), (ii) nontoxicity and (iii) low cost and natural abundance [1]. Despite its favourable comparison to commercial graphite anodes (theoretical capacity of 372 mA h g-1), the implementation of bulk Si anode has been hindered by the large volume change during the charging and discharging cycle (~ 300%). Such structural instability results in loss of contact with the other electrode constituents and self-destruction [2]. Another adverse feature is the limited Li⁺ ion diffusivity and electronic conductivity of bulk Si at room temperature. A scalable method of producing carbon (ultrafine silicon composite electrode) was developed using the Virtual Cathode Deposition technique [3]. As-deposited coatings contained silicon nano-crystallites encapsulated in a novel polymorph of mesoporous disordered carbon matrix. The architecture of the electrode offers close-order integration of both materials ensuring fast Li⁺ ion diffusivity and mixed-(ionic/electronic) conductivity as well as alleviating Si volume change during cycling. The composite carbon polymorph-silicon anode tested versus Li displayed a first cycle specific capacity of more than 2000 mAh g^-1 retaining in the following cycles ~1200 mAh g^-1 at a 0.1C rate. The good cyclability (over 80 cycles) demonstrated the effectiveness of such Si - carbon encapsulation, addressing the instability issues of Si-based anodes.

References:
[1] P. G. Bruce, S. A. Freunberger, L. J. Hardwick and J. M. Tarascon, Nat. Mater., 2012, 11, 19–29.
[2] Li B, Xiao Q, Luo Y (2018) A modified synthesis process of three dimensional sulfur/graphene aerogel as binder-free cathode for lithium-sulfur batteries. Mater Des 153:9–14
[3] D. Yarmolich, D. Virtual cathode deposition (vcd) for thin film manufacturing WO2016042530A1. (2015).

SESSION: BatteryFriPM1-R11	6th Intl. Symp. on Sustainable Secondary Battery Manufacturing and Recycling
Fri Oct, 25 2019 / Room: Coralino
Session Chairs: Guoran Li; Claudio Capiglia; Session Monitor: TBA

14:00: [BatteryFriPM105]
Feasibility of a Physical Vapor Deposition technology for battery electrode manufacturing
Dmitry Yarmolich¹ ; Rumen Tomov² ; Vasant Kumar² ; Carmen Murphy³ ; Yaroslav Odarchenko⁴ ; Dzianis Yarmolich⁵ ; Enrico Petrucco³ ; ¹Plasma App Ltd, OX11 0QX, United Kingdom; ²University of Cambridge, Cambridge, United Kingdom; ³Johnson Matthey Battery Materials, Reading RG4 9NH, United Kingdom; ⁴Plasma App Ltd, Oxford OX11 0QX, United Kingdom; ⁵Plasma App Ltd, Oxford , OX11 0QX, United Kingdom;
Paper Id: 504 [Abstract]

The method of physical vapor deposition has been tested for the manufacture of electric vehicle lithium-ion battery anodes. The anode was fabricated using Virtual Cathode Deposition1 (VCD) which enables direct deposition of 20 μm thick carbon active material onto a 25 μm polypropylene separator, followed by deposition of a 2 μm copper current collector. Carbon polymorphism2 induced by the deposition process is responsible for active material high gravimetric and volumetric capacity allowing anode areal capacity up to 4.2 mAh/cm2 at the 0.1 C charge rate. The PVD process increases the purity of active materials and quality control compared to the state-of-the-art wet chemical3 method. Currently, the production of a 24 kWh Nissan Leaf’s battery pack requires about 25 MWh, more than 80% of which is spent on drying the electrodes and dry room conditioning. VCD eliminates use of solvents that saves the energy for electrode drying and increase the environmental safety of battery production.

References:
1. Yarmolich, D. Patent No. WO2016042530A1 (September 2014).
2. Zhao, C. X., Niu, Ch. Y., Qin, Z-J., Ren, X. Y., Wang, J-T., Cho J.H. and Jia, Y. H18Carbon: A New Metallic Phase with sp2-sp3 Hybridized Bonding Network. Sci. Rep. 6, 1–9 (2016).
3. A. Sakti , J. J. Michalek, E. R.H. Fuchs, Jay F. Whitacre., A techno-economic analysis and optimization of Li-ion batteries for light-duty passenger vehicle electrification. Journal of Power Sources 273 (2015)
4. C. Yuan, Ye. Deng, T. Li, F. Yang, Manufacturing energy analysis of lithium ion battery pack for electric vehicles, CIRP Annals - Manufacturing Technology 66 (2017)