Fluorine-free water-based Ni-rich positive electrodes and their performance in pouch- and 21700-type cells

Radloff, Sonja; Carbonari, Gilberto; Scurtu, Rares-George; Hölzle, Markus; Wohlfahrt‐Mehrens, Margret

doi:10.1016/j.jpowsour.2022.232253

Cited by 8 publications

(8 citation statements)

References 39 publications

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“…These factors could influence the overall performance. With the exception of those from Radloff et al., [45] the cells tested in the other studies were comparably small (< 100 mAh), which could also explain a higher performance compared to the 3 Ah cells tested here. The fact that the cells with coated NMC811 show a 20 % higher initial discharge capacity emphasizes the importance of the protection of the NMC811 during water contact in the cathode production.…”

Section: Resultscontrasting

confidence: 67%

“…It is likely that phosphate surface species were also present in that case. Several other groups achieved higher initial DCs of up to 190 mAh/g CAM [18,27,44,45] . However, a lower ratio of anode:cathode capacity (N/P) was used within these studies, i. e., between 1.2 : 1 and 1.15 : 1.…”

Section: Resultsmentioning

confidence: 97%

“…Several other groups achieved higher initial DCs of up to 190 mAh/g CAM . [18,27,44,45] However, a lower ratio of anode: cathode capacity (N/P) was used within these studies, i. e., between 1.2 : 1 and 1.15 : 1. The N/P ratio of the cells in this study was 1.35 : 1.…”

Section: Resultsmentioning

confidence: 99%

“…To mitigate these problems, several strategies have been reported in literature. These strategies including the addition of acids, [16–21] the use of pressurized CO 2 , [22] adjusting the binder composition, [3,14,21,23] employing carbon‐coated aluminum foil [24] and applying surface coatings [13,25–27] . The latter approach is intended to limit the contact between the active material surface and water, ultimately reducing lithium leaching and enhancing cycling performance.…”

Section: Introductionmentioning

confidence: 99%

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Influence of Phosphate Surface Coating on Performance of Aqueous‐Processed NMC811 Cathodes in 3 Ah Lithium‐Ion Cells

Nagler,

Christian,

Gronbach

et al. 2024

ChemElectroChem

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Aqueous processing of state‐of‐the‐art cathode materials for lithium‐ion batteries like LiNi0.8Mn0.1Co0.1O2 (NMC811) has evolved as a more sustainable and cost‐effective alternative to the conventional 1‐methyl‐2‐pyrrolidone‐based process. However, the implementation of aqueous processing is challenging due to the water sensitivity of nickel‐rich layered oxides. This study investigates the influence of a phosphate‐based NMC811 surface coating on the performance of aqueous‐processed NMC811 cathodes in 3 Ah cells. The results show that the cells with phosphate‐coated NMC811 outperform those with uncoated NMC811, i. e., they exhibited higher initial capacity and improved capacity retention during cycling. Post‐mortem characterization techniques reveal that the phosphate coating limits the lithium loss during aqueous cathode manufacturing and further reduces side reactions during cycling, resulting in a smaller increase of cell impedance.

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Section: Resultscontrasting

confidence: 67%

Section: Resultsmentioning

confidence: 97%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Influence of Phosphate Surface Coating on Performance of Aqueous‐Processed NMC811 Cathodes in 3 Ah Lithium‐Ion Cells

Nagler,

Christian,

Gronbach

et al. 2024

ChemElectroChem

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“…In the check-up cycles, the cells were charged with a rate of 1 C. In the beginning of discharge, a 1 A discharge pulse (10 s) followed by a 10 A discharge pulse (1 s) was applied in order to measure the direct current internal resistance (DCIR). Then the cells were discharged at 0.2 C. The analysis of the DCIR values was performed in accordance with Radloff et al 44 Except of the check-up cycles, the discharge rate was 1 C in all cycling procedures for the 21700 cells.…”

Section: Cells-tablementioning

confidence: 99%

Multistep Improvement of Pilot-Scale 21700 Cells for Increased Fast-Charging Capability: Combining Optimized Electrolyte, Cell Design and Fast-Charging Protocol

Hogrefe,

Hölzle,

Wohlfahrt-Mehrens

et al. 2023

J. Electrochem. Soc.

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In this publication, different cell- and charging parameters (advanced fast-charging protocol, 21700 tab design, electrolyte composition) are changed in a systematic step-by-step approach to reduce charging time while keeping the anode and cathode cell chemistry and electrodes (graphite—NMC 622 full cell) unchanged. Preliminary tests were carried out using 3-electrode full cells with a Li metal reference electrode to identify charging conditions that avoid Li metal deposition. In addition, the effects of the anode potential are investigated in 3-electrode full cells with a Li metal reference electrode. The optimized charging protocols from the 3-electrode full cells were then transferred to 2-electrode pilot-scale 21700 full cells. Two different tab designs (1 × 1 welded tabs and 120 × 125 foil tabs) were used in these cells. To improve the charging time further, an electrolyte with higher ionic conductivity was used under the best conditions from the previous tests. Cross-sectional in situ optical microscopy was used to visualize the transport effects within the anode. In the optimized 21700 cell (advanced fast-charging, 120 × 125 foil tabs, better Li+ transport in the electrolyte), the synergistic effects of the three different optimization steps reduced the charging time to 80% SOC by 46% compared to the baseline cell.

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Enabling Aqueous Processing of Ni‐Rich Layered Oxide Cathodes via Systematic Modification of Biopolymer (Polysaccharide)‐Based Binders

Albers,

Timmermann,

Brake

et al. 2024

Adv Energy and Sustain Res

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Aqueous processing of lithium (ion) battery cathodes based on Ni‐rich layered oxides like LiNi0.83Co0.12Mn0.05O2 (NCM) can reduce costs, increase sustainability, and pave the way for F‐free, e.g., biopolymeric binders, however, the degradation of water‐sensitive Ni‐rich NCM remains a challenge. Besides strategies like NCM coatings and processing additives, customized binders can be performance‐decisive via impacting both, electrode processing aspects (paste viscosity, particle dispersibility, etc.) and chemical interactions with NCM surface, though, a distinction between these two impacting factors is difficult given their mutual influences. For this reason, a bifunctional binder system is chosen in this work, i.e., highly viscous xanthan and low viscous pullulan, both polysaccharides known from the food industry, which realize constant viscosity and processing, finally enabling systematic investigation of binder modifications (here pullulan) with various side groups. In fact, while the rate performance remains constant, suggesting a similar composite network with comparable electronic and ionic conductivities, the modified binders affect the NCM||graphite cycle life, where a higher substitution degree of carboxymethylated pullulan can even compete with N‐methyl‐2‐pyrrolidone/polyvinylidene difluoride state‐of‐the‐art system at conventional upper charge voltage (4.2 V); while at 4.5 V water‐reasoned NCM damages get obvious, as seen by enhanced electrode cross‐talk via transition metal deposition on anode.

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Fluorine-free water-based Ni-rich positive electrodes and their performance in pouch- and 21700-type cells

Cited by 8 publications

References 39 publications

Influence of Phosphate Surface Coating on Performance of Aqueous‐Processed NMC811 Cathodes in 3 Ah Lithium‐Ion Cells

Influence of Phosphate Surface Coating on Performance of Aqueous‐Processed NMC811 Cathodes in 3 Ah Lithium‐Ion Cells

Multistep Improvement of Pilot-Scale 21700 Cells for Increased Fast-Charging Capability: Combining Optimized Electrolyte, Cell Design and Fast-Charging Protocol

Enabling Aqueous Processing of Ni‐Rich Layered Oxide Cathodes via Systematic Modification of Biopolymer (Polysaccharide)‐Based Binders

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