Stabilization of Si Negative Electrode by Li Pre-doping Technique and the Application to a New Energy Storage System

Abstract

To extend the cyclability of a hybrid capacitor using Li pre-doped Si negative electrodes (NEs) (Si-CAP), we applied a polyimide binder and fluoroethylene carbonate (FEC) as additives in the Li pre-doping step. This binder successfully improved the cyclability by fixing Si nanoparticles as the NE active material on the Cu foil current collector to resist the volume change caused by Li-Si alloying. After Li pre-doping, there were no cracks on the Si NE surfaces, which had been observed in previous work using sodium carboxymethyl cellulose binder. Furthermore, FEC addition into the electrolyte at Li pre-doping improved homogeneity of the Li-Si alloying. As a result, a large amount of Li was pre-doped to the Si NE and a lower open-circuit potential was maintained. A Si-CAP cell of [Li alloyed Si | activated carbon] using polyimide binder exhibited relatively stable charge/discharge behavior and cyclability was maintained up to 800 cycles. Stability of the charge/discharge performance of FEC-containing Si-CAP was improved by formation of a LiF-rich solid-state interphase film on the Si NE. X-ray photoelectron spectroscopy revealed suppression of decomposition of the propylene carbonate solvent by electrochemical reduction.

Prelithiation: A Crucial Strategy for Boosting the Practical Application of Next-Generation Lithium Ion Battery

“…A scalable roll-to-roll production line for this prelithiation was compatible with the current battery manufacturing process (Figure f), which was promising commercially. It is also reported in literature that other anodes were prelithiated using this prelithiation method, such as Si, , amorphous carbon, hard carbon, graphite, and carbon-coated ZnFe 2 O 4…”

“…A scalable roll-to-roll production line for this prelithiation was compatible with the current battery manufacturing process (Figure 8f), which was promising commercially. It is also reported in literature that other anodes were prelithiated using this prelithiation method, such as Si, 125,126 amorphous carbon, 127 hard carbon, 128 graphite, 129 and carbon-coated ZnFe 2 O 4 . 130 In addition, a lithium−metal-free electrochemical prelithiation method (Figure 8g) was developed on the basis of a electrolytic cell configured with a Cu pitting corrosion type anode and a Si lithiation type cathode as well as a lithium super-ionic conductor (LISICON) separator.…”

Unraveling the Design Principles of Battery‐Supercapacitor Hybrid Devices: From Fundamental Mechanisms to Microstructure Engineering and Challenging Perspectives

“…[ 97 ] The impact of the additives on the polycarbonate (PC)‐based electrolyte was revealed by Naka‐cho et al., which not only enhanced the homogeneity of Li pre‐doping, but also prevented the decomposition of the PC solvent, leading to lower charge‐transfer resistance of SEI film. [ 98 ] Besides, a robust and lithiophilic Li‐enriched LiN nanoshield constructed in situ at the surface of Ge anode was also demonstrated for improving cycling stability and rate performance. The resulting anode achieved high rate capability (1060 mAh g −1 at 2 A g −1 ) and excellent cycling stability (1024 mAh g −1 after 300 cycles at 1 A g −1 ).…”

Advanced and Emerging Negative Electrodes for Li-Ion Capacitors: Pragmatism vs. Performance

“…Combined, these approaches delivered 114 Wh kg −1 electrodes (utilizing 700 mAh g Si−1 vs. 224 mAh g −1 in the control sample) at 1.0 mA cm −2 after 50 cycles, demonstrating the advantages delivered by the prelithiated Si. In a following work, the group managed to extend the cyclability to 800 cycles by replacing sodium carboxymethyl cellulose binder with polyimide [81].…”

“…Such KPIs for the most popular materials which are expected to be commercialized in the nearest future are listed in Table 1. [73] 3579 [73] 800 [81] Very high Very high 3 Furthermore, the authors believe that in addition to the Ragone plot for graphical representation of potential approaches, the advancements in materials for LICs are better represented by the spider diagram which accounts for all KPIs described above. Therefore, such a diagram for the most promising materials (TiO 2 , Nb 2 O 5 , TNO and Si) is shown below in Figure 9.…”