Unlocking Stable Multi‐Electron Cycling in NMC811 Thin‐Films between 1.5 – 4.7 V. Issue 40 (1st September 2022)

• Record Type: Journal Article
• Authors: Aribia, Abdessalem; Sastre, Jordi; Chen, Xubin; Futscher, Moritz H.; Rumpel, Matthias; Priebe, Agnieszka; Döbeli, Max; Osenciat, Nicolas; Tiwari, Ayodhya N.; Romanyuk, Yaroslav E.
• Is Part Of: Advanced energy materials. Volume 12:Issue 40(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-09-01
• Subjects: Li‐rich Ni‐based cathodes -- NMC811 -- solid‐state lithium‐ion batteries -- thin‐films; Energy harvesting -- Materials -- Periodicals; Energy conversion -- Materials -- Periodicals; Energy storage -- Materials -- Periodicals; Photovoltaics -- Periodicals; Fuel cells -- Periodicals; Thermoelectric materials -- Periodicals; 621.31
• DOI: 10.1002/aenm.202201750
• Languages: English
• ISSNs: 1614-6832

Abstract

Abstract: Among cathode materials, LiNi0.8 Mn0.1 Co0.1 O2 (NMC811) is the most discussed for high performance Li‐ion batteries, thanks to its capacity of ≈200 mAh g ‐1 and low Co content. Here, it is demonstrated that NMC811 can reversibly accommodate more than one Li‐ion per formula unit when coupled with a solid‐state electrolyte, thus significantly increasing its capacity. Sputtered Li‐rich NMC811 cathodes are tested with lithium–phosphorus–oxynitride as a solid‐state electrolyte in a thin‐film architecture, which is a simplified 2D model with direct access to the cathode‐electrolyte interface. The solid‐state electrolyte helps to stabilize the interface and prevents capacity fading, voltage decay, and interface resistance growth, thus allowing cycling at extended voltage ranges of 1.5–4.7 V. While the liquid electrolyte cells suffer from rapid capacity decay, the Li‐rich NMC811 cells with the solid‐state electrolyte can cycle at a fast rate and an initial capacity of 149 mAh g ‐1 from 1.5 to 4.3 V for 1000 cycles. The all‐solid‐state thin‐film cells with a lithium metal anode yield a discharge capacity of up to 350 mAh g ‐1 at C/10 because of multi‐electron cycling with a coulombic efficiency of 90.1%. The results demonstrate how solid‐state electrolytes that are stable against NMC811 cathodes can unlock the full potential of this Li‐rich and Ni‐rich cathode class. Abstract : Li‐rich and Ni‐rich Li2 Ni0.8 Mn0.1 Co0.1 Ox (LR‐NMC811) thin‐film cathodes are fabricated by magnetron sputtering. In combination with a lithium–phosphorus–oxynitride (LiPON) electrolyte, stable cycling at 1.5–4.7 V is observed. This is in contrast to liquid organic electrolytes where LR‐NMC811 is held back by voltage hysteresis and rapid impedance rise. LR‐NMC811 cells with solid electrolyte displayed initial capacities of 350 mAh g −1 due to multi‐electron cycling.