Diffusion-induced stress optimization by boosted surface Li-concentration for single-crystal Ni-rich layered cathodes. (December 2022)

• Record Type: Journal Article
• Authors: Liu, Yun; Wang, Qi; Chen, Lai; Xiao, Zhiming; Fan, Xinming; Ma, Shuailing; Ming, Lei; Tayal, Akhil; Zhang, Bao; Wu, Feng; Ou, Xing
• Is Part Of: Materials today. Volume 61(2022)
• Page Start: 40
• Page End: 53
• Publication Date: 2022-12
• Subjects: Lithium-ion batteries -- Single-crystalline Ni-rich cathode -- Surface modification -- Lithium concentration -- Diffusion-induced stress; Materials science -- Periodicals; Metallurgy -- Periodicals; Metal-work -- Periodicals; Biomedical and Dental Materials -- Periodicals; Manufactured Materials -- Periodicals; Metals -- Periodicals; 620.11
• DOI: 10.1016/j.mattod.2022.10.021
• Languages: English
• ISSNs: 1369-7021

Abstract

Graphical abstract: A surficial engineering strategy for single-crystalline LiNi0.83 Co0.11 Mn0.06 O2 (SCNCM) via Li1.3 In0.3 Ti1.7 (PO4 )3 (LITP) modification is proposed to promote the Li-ions distribution. Notably, the fast Li-ion conductor LITP can not only accelerate the Li-ions diffusion and alleviate the electrode–electrolyte side reaction simultaneously, but also serve as the Li-ions regulator to ensure the homogeneous distribution of Li-ions and minimizing the concentration difference at SCNCM surface. It provides the instructive guide for the modification of single-crystalline micron-sized particles for commercialization development of advanced NCM cathode at harsh testing condition. Abstract: Nickel-rich layered LiNi x Co y Mn1- x - y O2 (NCM, x ≥ 0.83) is considered as a promising cathode material for lithium-ion batteries (LIBs), owing to its satisfying specific energy. However, the undesired phase transformation from layered into rock-salt at the NCM surface will easily induce Li concentration gradient during cycling, which hinders the Li-ions diffusion and leads to the gradual accumulation of inner stress with the appearance of microcracks. Herein, we propose a surficial engineering strategy to promote the Li-ions transmission for single-crystalline LiNi0.83 Co0.11 Mn0.06 O2 (SCNCM) via Li1.3 In0.3 Ti1.7 (PO4 )3 (LITP) modification. It is noted that, as the fast Li-ion conductor, LITP can accelerate the Li-ions diffusion and alleviate the electrode–electrolyte side reaction simultaneously. More importantly, LITP can serve as the Li-ions regulator, ensuring the homogeneous distribution of Li-ions and minimizing the concentration difference at SCNCM surface. It can relieve the stress induced by the inconsistent Li-ions dispersion, which effectively decreases the degree of structural disordering and lattice mismatch at surface, eventually maintaining the high structure integrity during long-term cycling. As anticipated, even under the harsh testing conditions, the LITP modified SCNCM still can achieve a satisfied reversible capacity of 196.4 mAh g −1 under potential range of 2.75–4.6 V after 200 cycles at 25 °C in coin-type half-cells. Furthermore, it provides an extraordinary capacity retention of 88% in 2.75–4.3 V after 400 cycles at high temperature of 45 °C in pouch-type full-battery.