Yang Kai, Liu Qirong, Zheng Yongping, Yin Hang, Zhang Shanqing, Tang Yongbing
Functional Thin Films Research Center, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China.
Nano Science and Technology Institute, University of Science and Technology of China, Suzhou, 215123, China.
Angew Chem Int Ed Engl. 2021 Mar 15;60(12):6326-6332. doi: 10.1002/anie.202016233. Epub 2021 Feb 8.
Dual-ion batteries (DIBs) inherently suffer from limited energy density. Proposed here is a strategy to effectively tackle this issue by employing locally ordered graphitized carbon (LOGC) cathodes. Quantum mechanical modeling suggests that strong anion-anion repulsions and severe expansion at the deep-charging stage raise the anion intercalation voltage, therefore only part of the theoretical anion storage sites in graphite is accessible. The LOGC interconnected with disordered carbon is predicted to weaken the interlaminar van der Waals interactions, while disordered carbons not only interconnect the dispersed nanographite but also partially buffer severe anion-anion repulsion and offer extra capacitive anion storage sites. As a proof-of-concept, ketjen black (KB) with LOGC was used as a model cathode for a potassium-based DIB (KDIB). The KDIB delivers an unprecedentedly high specific capacity of 232 mAh g at 50 mA g , a good rate capability of 110 mAh g at 2000 mA g , and excellent cycling stability of 1000 cycles without obvious capacity fading.
双离子电池（DIBs）本质上存在能量密度有限的问题。本文提出了一种通过使用局部有序石墨化碳（LOGC）阴极来有效解决这一问题的策略。量子力学模型表明，在深度充电阶段强烈的阴离子 - 阴离子排斥和严重的膨胀会提高阴离子嵌入电压，因此石墨中只有部分理论阴离子存储位点是可利用的。预计与无序碳互连的LOGC会削弱层间范德华相互作用，而无序碳不仅使分散的纳米石墨相互连接，还能部分缓冲严重的阴离子 - 阴离子排斥，并提供额外的电容性阴离子存储位点。作为概念验证，具有LOGC的科琴黑（KB）被用作钾基双离子电池（KDIB）的模型阴极。该KDIB在50 mA g 时具有前所未有的232 mAh g 的高比容量，在2000 mA g 时具有110 mAh g 的良好倍率性能，以及1000次循环的出色循环稳定性且无明显容量衰减。
