Study on solid electrolyte interphase excessive growth caused by Mn (II) deposition on silicon anode

Mechanism and Control Strategies of Lithium-Ion Battery Safety: A Review

Lithium-ion batteries (LIBs) are extensively used everywhere today due to their prominent advantages. However, the safety issues of LIBs such as fire and explosion have been a serious concern. It is important to focus on the root causes of safety accidents in LIBs and the mechanisms of their development. This will enable the reasonable control of battery risk factors and the minimization of the probability of safety accidents. Especially, the chemical crosstalk between two electrodes and the internal short circuit (ISC) generated by various triggers are the main reasons for the abnormal rise in temperature, which eventually leads to thermal runaway (TR) and safety accidents. Herein, this review paper concentrates on the advances of the mechanism of TR in two main paths: chemical crosstalk and ISC. It analyses the origin of each type of path, illustrates the evolution of TR, and then outlines the progress of safety control strategies in recent years. Moreover, the review offers a forward-looking perspective on the evolution of safety technologies. This work aims to enhance the battery community's comprehension of TR behavior in LIBs by categorizing and examining the pathways induced by TR. This work will contribute to the effective reduction of safety accidents of LIBs.

Understanding the Effect of Cathode Composition on the Interface and Crosstalk in NMC/Si Full Cells

Crosstalk between the cathode and the anode in lithium-ion batteries has a great impact on performance, safety, and cycle lifetime. However, no report exists for a systematic investigation on crosstalk behavior in silicon (Si)-based cells as a function of transition metal composition in cathodes. We studied the effect of crosstalk on degradation of Si-rich anodes in full cells with different cathodes having the same crystal structure but different transition metal compositions, such as LiNi_1/3Mn_1/3Co_1/3O₂ (NM111), LiNi_0.5Mn_0.3Co_0.2O₂ (NMC532), and LiNi_0.8Mn_0.1Co_0.1O₂ (NMC811). We found that the transition metal composition in cathodes, especially Mn ion concentration, significantly affects electrolyte decomposition reactions, even from very early cycles. This change causes differences in the solid electrolyte interphase (SEI) chemistry of each aged Si sample. As a result, each of the aged Si samples has a different electrochemistry, in terms of initial Coulombic efficiency and the mechanism of capacity fade.

Novel graphitic sheets with ripple-like folds as an NCA cathode coating layer for high-energy-density lithium-ion batteries

In this work, novel graphitic sheets with ripple-like folds (GSRFs) are synthesized from cheap resin via a facile route. The obtained GSRFs are used as a cladding layer for LiNi0.8Co0.15Al0.05O2 (NCA) particles to construct a GSRF@NCA composite cathode. Electrochemical testing for GSFR@NCA exhibits better cycling and C-rate performance than those of original NCA. Moreover, the capacity retention (85%) of the full-cell (GSFR@NCA versus graphite) is much higher than that (79%) of the full-cell (NCA versus graphite) after 400 cycles. Most importantly, this approach allows the preparation of GSFR@NCA with highly promising applications as a cathode for high-energy-density lithium-ion batteries, since in this contribution just simple equipment and a precursor with low cost are involved.

Quantification on Growing Mass of Solid Electrolyte Interphase and Deposited Mn(II) on the Silicon Anode of LiMn2O4 Full Lithium-Ion Cells

Silicon is considered to be one of the most important high-energy density anode materials for next-generation lithium-ion batteries. A large number of experimental studies on silicon anode have achieved better results, and greatly promoted its practical application potentiality, but almost of them are only tested in metal lithium half batteries. There is still an unavoidable question for commercial applications: what is the performance of the full cell composed of a silicon anode and a manganese-based material cathode? In this paper, the growing solid electrolyte interphase (SEI) and deposited manganese ions of the silicon anode's surface of the spinel lithium manganese oxide LiMn₂O₄/silicon full cells are quantitatively studied during electrochemical cycling, and the SEI performances are tested by differential scanning calorimetry to find out the reason for the rapid decline of reversible capacity in the LiMn₂O₄/silicon system. The experimental results show that manganese ions can make SEI films rapidly grow on the silicon anode and make SEI films more brittle, which results in lower Coulombic efficiency and rapid decline in capacity of the silicon anode.