Simultaneous Interphase Optimizations on the Large-Area Anode and Cathode of High-Energy-Density Lithium-Ion Pouch Cells by a Multiple Additives Strategy

Abstract

Prior to the maturation of next-generation energy storage devices, the actual lithium-ion batteries for commercial purposes are still expected to fulfill some critical requirements, among which the high energy density, wide operating temperature range, and related long-term cycling stability are the most challenging issues. Herein a multiple additives strategy is employed to simultaneously optimize the solid electrolyte interphase on the large-area anode and cathode in a 2 Ah artificial graphite (AGr)/LiNi 0.5 Co 0.2 Mn 0.3 O 2 (NCM523) pouch cell with high gravimetric (>260 Wh kg −1 ) and volumetric (>630 Wh L −1 ) energy density. By introducing a rational mixture of electrolyte additives, a highly sulfurized surface layer and a uniform and thin passivation layer are separately formed on the anode and cathode of the AGr/NCM523 pouch cell, exhibiting high storage stability at 60 °C, much improved discharge capacity at −10 and −20 °C, high anodic stability at high voltage of 4.4 V, and stable cyclic performance with a capacity retention of 85.5% after 500 cycles, significantly outperforming the value of 75.7% after only 200 cycles of the cell without additional additives. These results demonstrate the critical effect of simultaneous optimizations of anode and cathode interphase layers to construct stable high-energy-density lithium-ion pouch cells.

Challenges and Advances in Wide‐Temperature Electrolytes for Lithium‐Ion Batteries

“…Consequently, recent efforts have concentrated on developing novel multifunctional electrolyte additives [73][74][75][76][77][78][79] and exploring the synergistic effects of mixed additives. [80][81][82][83][84] In the following text, a detailed discussion of recent endeavors concerning novel wide-temperature additives is provided. Lu et al [76] investigated phenyl 4-fluorobenzene sulfonate (PFBS), a pioneering electrolyte additive encompassing both À OSO 2 À and À F functional groups.…”

“…The multiadditive approach aids in forming highly conductive layers on electrode surfaces (Figure 6a), which significantly improve the cycling stability of the graphite anode and NCA/NMC cathode over a wide temperature range. Zhang et al [82] also designed an electrolyte consisting of multiple additives, including 1,3,2dioxathiolane-2,2-dioxide (DTD), Li 2 PO 2 F 2 , LiFSI, VC, and 1,3-PS. This electrolyte enables the creation of a highly sulfidized layer on the artificial graphite (AGr) anode and a uniform passivation layer on the LiNi 0.5 Co 0.2 Mn 0.3 O 2 (NCM523) cathode, which contribute to promoting rapid Li + transfer, inhibiting electrolyte decomposition, stabilizing the electrode structure, and mitigating the dissolution of transition metal ions from the NCM523 cathode (Figure 6b).…”

“…Nevertheless, individual additives often fail to address the challenges faced by LIBs at both low and high temperatures. Consequently, recent efforts have concentrated on developing novel multifunctional electrolyte additives [73–79] and exploring the synergistic effects of mixed additives [80–84] …”

“…The multi‐additive approach aids in forming highly conductive layers on electrode surfaces (Figure 6a), which significantly improve the cycling stability of the graphite anode and NCA/NMC cathode over a wide temperature range. Zhang et al [82] . also designed an electrolyte consisting of multiple additives, including 1,3,2‐dioxathiolane‐2,2‐dioxide (DTD), Li 2 PO 2 F 2 , LiFSI, VC, and 1,3‐PS.…”

Review on Action Mechanism and Characterization of Natural/Artificial Solid Electrolyte Interphase of Lithium Battery: Latest Progress and Future Directions

“…The cryo-TEM with subangstrom spatial resolution is relatively easy to analyze the formation mechanism of the SEI structure in the electrolyte added with ethylene carbonate (VC) to optimize the electrode electrolyte interphase. − The results given by Xu et al include the complete process of electrochemical SEI formation, which is of great significance for the subsequent study of the microscopic mechanism of SEI films. In addition, Lee et al have not gained a clear understanding of the formation mechanism and composition − of SEI caused by the electrochemical reaction at the graphite electrode/electrolyte interface. Considering the influence of accelerating voltage, the study uses transmission electron microscopy and electron energy loss spectroscopy (EELS) under a low-speed voltage to study the cross-sectional fiber grinding microstructure to observe the morphology and composition of the microscopic SEI structure for comparison.…”