Scholarlink

<p>High-voltage LiCoO<sub>2</sub> (LCO) cathodes based lithium-ion batteries (LIBs) provide high energy density, but their long-cycle stability is compromised by detrimental side reactions at high voltages and elevated temperatures. Herein, we demonstrate that the performance limitations of high-voltage LCO cathodes can be substantially alleviated by incorporating cyanobenzene (CB) as&#xa0;an electrolyte additive. The addition of 1 wt.% CB to a commercial electrolyte enables&#xa0;4.2 Ah LCO||graphite pouch cells operating at 4.53&#xa0;V to&#xa0;retain 80% of their initial capacity after 550 cycles at a current density of 1.0 C under an elevated temperature of 45&#xa0;°C. It outperforms the cell that achieves 80% of their initial capacity after 450 cycles with 1 wt.% 1,3,6-hexanetricarbonitrile (HTCN), a well-known commercial nitrile additive. Experimental results and theoretical analyses reveal that this significant improvement is attributed to the formation of a more robust cathode electrolyte interphase (CEI) film induced by the CB additive. CB is more readily oxidized than HTCN, effectively suppressing the oxidative decomposition of electrolyte components and preserving the structural integrity of LCO under high-voltage conditions. Furthermore, CB demonstrates superior compatibility with graphite anodes relative to HTCN. This work highlights the critical role of nitrile molecular structure in forming a stable CEI on high-voltage cathodes, providing valuable guidance for improving the energy density of LIBs from facile interface engineering tactics.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Long-cycle stability of high-voltage LiCoO2 cathode by nitrile electrolyte additives

  • 期刊论文

  • 发表日期：

    2025年9月18日

查看全文
  • Hai Wang,
  • Ling Lv,
  • Haikuo Zhang,
  • Shuai Chen,
  • Xiulin Fan,
  • Youhao Liao,
  • Weishan Li

摘要

High-voltage LiCoO2 (LCO) cathodes based lithium-ion batteries (LIBs) provide high energy density, but their long-cycle stability is compromised by detrimental side reactions at high voltages and elevated temperatures. Herein, we demonstrate that the performance limitations of high-voltage LCO cathodes can be substantially alleviated by incorporating cyanobenzene (CB) as an electrolyte additive. The addition of 1 wt.% CB to a commercial electrolyte enables 4.2 Ah LCO||graphite pouch cells operating at 4.53 V to retain 80% of their initial capacity after 550 cycles at a current density of 1.0 C under an elevated temperature of 45 °C. It outperforms the cell that achieves 80% of their initial capacity after 450 cycles with 1 wt.% 1,3,6-hexanetricarbonitrile (HTCN), a well-known commercial nitrile additive. Experimental results and theoretical analyses reveal that this significant improvement is attributed to the formation of a more robust cathode electrolyte interphase (CEI) film induced by the CB additive. CB is more readily oxidized than HTCN, effectively suppressing the oxidative decomposition of electrolyte components and preserving the structural integrity of LCO under high-voltage conditions. Furthermore, CB demonstrates superior compatibility with graphite anodes relative to HTCN. This work highlights the critical role of nitrile molecular structure in forming a stable CEI on high-voltage cathodes, providing valuable guidance for improving the energy density of LIBs from facile interface engineering tactics.