Improving Wetting Behavior and C‐Rate Capability of Lithium‐Ion Batteries by Plasma Activation

Abstract

Climate change is part of today's most complex global challenges. Social efforts to achieve sustainable and CO 2 -neutral ways to provide mobility as well as for electrical energy production, induce ambitious challenges to energy storage. In the field of rechargeable batteries, the lithium-ion-battery (LIB) is today's most promising approach, to match all energy storage requirements of electric vehicles (mobile energy storage) as well as for grid stabilization (stationary energy storage). Since their first commercialization by Sanyo, Sony, and Matsuhita in the early 1990ies, [1] LIBs enabled a wide range of portable electronics. Nevertheless, LIBs still require further improvements in terms of energy density, power density, lifetime, safety, and cost reduction, which presently drives enormous research efforts to focus on these topics. Typical research fields cover the advancement of active and inactive electrode materials, separators, electrolytes, as well as manufacturing techniques. Simulation approaches for characterization of fundamental physical and chemical processes during LIB operation highlighted surfaces and interfaces to have a substantial influence on LIB kinetics, in terms of electrolyte mass transport, charge-transfer (CT) reactions at anodic and cathodic active material (AM) particles, and electronic resistance at the electrode--current collector interface. Significant improvements to battery performance by surface/interface modification were yet demonstrated by calendering [2,3] or laser structuring [4][5][6][7][8] of electrodes, lamination of electrodes and separator, [9] or by enlargement of the current collector micro-surface. [10][11][12][13][14] Plasma-processes are well-known as a helpful tool in the field of LIBs. [15] Plasma-processes enable the production of nanosized AM particles, [16][17][18] carbon-based conductive AM coatings, [19] specialized 3D architectures for electrode nanowires, [20,21]

Modification of Battery Separators via Electrospinning to Enable Lamination in Cell Assembly

“…This is a well known artifact arising from normalization to geometric electrode surface (despite BET electrode surface) and can therefore act as an indicator for correct assignment of the semicircle fit parameters [6,15]. Surface resistance fit parameters (see Figure 6) in general are significantly higher than in any of our previous studies that included EIS on NMC-graphite single cells [6][7][8]14], or in comparable literature [16,17]. This might either suggest an extraordinary high contribution of the cathode current collector interface (non calendered cathode) or indicate an additional contribution of the separator itself, which was not reported in literature so far to our best knowledge.…”

“…EIS data were processed in a MATLAB environment (MATLAB R2017b, MathWorks, Natick, USA), including the open source Z-fit protocol. Equivalent circuit fit (see Supplementary Material Figure S2) was conducted in identical manner like we discussed in a previous study [14], using the same fit model due to analogous conditions of the measurement environment. Fundamentals on the chosen fit model and its scientific background were provided in detail in this study [14].…”

“…Equivalent circuit fit (see Supplementary Material Figure S2) was conducted in identical manner like we discussed in a previous study [14], using the same fit model due to analogous conditions of the measurement environment. Fundamentals on the chosen fit model and its scientific background were provided in detail in this study [14]. EIS datasets and fit parameters were normalized to the geometric area of active cathode coating in our single cells (40 cm 2 ).…”

A Systematic Literature Analysis on Electrolyte Filling and Wetting in Lithium-Ion Battery Production

“…For example, an article published in October 2022 demonstrates an improvement in wetting behavior due to plasma activation of the electrodes. In this process, the surface of the electrode material is treated with plasma before the packaging process in order to accelerate the absorption of the electrolyte and improve the C-rate capability in a subsequent application [73].…”