Ante-mortem analysis, electrical, thermal, and ageing testing of state-of-the-art cylindrical lithium-ion cells

Abstract

Thanks to its exceptional performance in terms of high energy and power density as well as long lifespan, the lithium-ion secondary battery is the most relevant electrochemical energy storage technology to meet the requirements for partial or full electrification of vehicles (plug-in hybrids or pure electric vehicles), and thanks to decreasing cost and ongoing technical improvements, it will maintain this role in the near to mid-term future. This study benchmarks eight different (five 21700 and three 18650 format) high-energy cylindrical cells concerning their suitability for automotive applications and aims to give a holistic overview and comparison between them. Therefore, an ante-mortem material analysis, a benchmark of electrical and thermal values as well as a cycle life study were carried out. The results show that even when applying similar concepts like Nickel-rich cathodes with graphite-based anodes, the cells show wide variations in their performance under the same test conditions.

Path‐Dependent Ageing of Lithium‐ion Batteries and Implications on the Ageing Assessment of Accelerated Ageing Tests

“…The cells use NCA as positive, and a SiO/Gr-blend as negative active-material. [23,24] As in literature, different nominal capacities are mentioned between 3.35 Ah to 3.4 Ah, [25][26][27] we use 3.4 Ah as nominal capacity C N for charge amounts and current rates throughout this study to avoid any confusion. The cells are divided into three groups with six cells each, whereas one group represent one of three chosen sequential permutation of ageing paths.…”

In-situ temperature monitoring of a lithium-ion battery using an embedded thermocouple for smart battery applications

“…Commercial cylindrical cells LG-M50 (21700 format) were selected for instrumentation. These cells are popular in automotive and energy storage applications, due to their energy density and relatively long cycle-life [28]. The cells comprise a NMC 811 formulation for the cathode and a Graphite-SiO x anode.…”

Determination of Internal Temperature Differences for Various Cylindrical Lithium-Ion Batteries Using a Pulse Resistance Approach

“…For this study, the three cylindrical cells listed in Table 2 were selected. The 18650 and the 21700 cells were selected since they represent the latest nickel manganese cobalt oxide (NMC) chemistry with silicon content in the anode composite and a nickel-rich cathode material [33]. Furthermore, the 18650 was investigated in our previous studies [27,28] and the 2D thermal model of both cells (18650 and 21700) was already implemented and validated in the study of Steinhardt et al [31].…”