基于析氮反应的新型高比能硅-硫化聚电池

论文概述

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关键词

Nitrogen evolution reaction;

High specific energy;

Silicon–sulfur battery;

Lithium metal-free;

High Coulombic efficiency

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导读

高比能锂-硫电池的实际应用面临两大致命障碍: 一是源于硫正极的“穿梭效应”, 二是锂金属负极带来的低库仑效率和安全问题. 为了彻底解决这些问题, 研究人员提出了一种新型的硅-硫化聚(丙烯腈)全电池. 在这种不含锂金属的系统中, 锂源被预加载在正极中, 采用析氮反应将锂离子注入硅基负极. 基于固-固转化机制的硫化聚(丙烯腈)正极可以从根本上规避“穿梭效应”. 同时, 与锂金属负极相比, 硅基负极可以实现更有效的利用和更高的安全性. 采用该技术的全电池可提供1169.3 mAh g⁻¹的容量并稳定循环100次, 显示出优异的电化学稳定性. 此外, 即使在4.2 mg cm⁻²高硫载量的实用软包电池也可以实现513.2 Wh kg⁻¹的高比能量. 本文还通过原位方法研究和分析了正极中析氮反应的机制. 值得注意的是, 这种电池设计完全匹配当前的电池生产工艺, 制造成本低, 为采用析氮反应开发无金属锂电池开辟道路.

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图文速览 

Figure 1  Practical operating potential, specific capacity and energy density for common lithium-ion batteries based on the weight of the cathode material (top part, represented by a triangle symbol). Practical output potential and specific capacity for common anode materials (bottom part, represented by a square symbol).

Figure 2  Schematic illustration of the nitrogen evolution reaction (NER) process and the corresponding reaction equations, and the advantages of this battery system were also shown in the schematic illustration.

Figure 3  In situ GC-MS characterization during the NER process of Li₃N–S/PAN vs. the Si/C cell at 0.5 mA (Right). A value of 6.4 e⁻/N₂ for the charge passed during the charging process/integration of the N₂ generation rate was obtained, corresponding to the desired Li₃N oxidation to N₂. In situ XRD characterization of the anode side (Si/C) and cathode side (Li₃N) for Li₃N–S/PAN vs. the Si/C cell during the initial charging process (Left). 

Figure 4  (a) Cycling stability of S/PAN vs. Li metal cell and (b) cycling stability of Si/C vs. Li metal cells at 500 mA g⁻¹; the corresponding charge/discharge curves of (c) S/PAN vs. Li and Si/C vs. Li half cells. (d) Cycling stability of Li₃N–S/PAN vs. the Si/C (4 mAh) coin cell at 500 mA g⁻¹ after the initial charging process, and the inset presents the corresponding charge/discharge curves.Figure 5  (a) Schematic of the designed pouch cell based on the NER process; (b) the inner structure of pouch cell. (c) The initial charging process of practical pouchcell and (d) the following cycling stability; inset presents the corresponding charge/discharge curves of the first three cycles at 1 mA, which could delivera capacity of 61.5 mAh with a total sulfur loading of 83.4 mg.

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文章信息 

Pengfei Wang, Chao Xia, Jingui Yang, Xuewei He, Kezhong Lv, Siyun Ren, Hucheng Song, Jiulin Wang, Ping He, Haoshen Zhou. High-energy silicon-sulfurized poly(acrylonitrile) battery based on a nitrogen evolution reaction. Science Bulletin, 2022, 67(3): 256–262， doi：10.1016/j.scib.2021.10.007

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