An effective approach to improve electrochemical performance of thick electrodes
An effective approach to improve electrochemical performance of thick electrodes
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提高厚电极电化学性能的有效途径
DOI：
10.1007/s11581-021-03912-6
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发表时间：
2021-01
期刊：
影响因子：
2.8
通讯作者：
Zhang Lan
中科院分区：
文献类型：
--
作者：
Song Kaifang;Li Wenjie;Chen Zhan;Wu Xiangkun;Zhou Qian;Snyder Kent;Zhang Lan
通过厚电极增加活性物质的面积负载量是提高锂离子电池能量密度的直接有效途径。然而，它也可能引起大的极化效应并降低活性材料利用率，特别是在高充电/放电电流密度下。本文采用分层法制备了具有5 mAh/cm 2的高面容量和梯度孔隙率的双层LiNi 0. 8 Co 0. 15 Al 0. 05 O2（NCA）正极材料，其中碳纳米管（CNTs）和Super P（SP）碳用于构建电子传导网络并调节孔隙率。它表明，CNT-SP阴极，其中使用CNT作为导电剂在下层（靠近集流体）和SP作为导电剂在上层（靠近隔离物），提供了最高的面积容量为4.81 mAh/cm 2之间的所有配置研究（CNT-SP，SP-SP，SP-CNT，和CNT-CNT）。在NCA中100次循环容量保持率高达99.5||石墨全袋电池，电流密度为0.2C倍率。厚CNT-SP阴极的优异性能归因于良好的导电网络的构建，该导电网络可以为电子传输和Li+扩散提供有效和可靠的路径。此外，发现在CNT-SP电极中形成较薄的电极/电解质界面层。这项研究揭示了一种可行的方法，用于改善显着的极化效应和有限的活性材料利用厚电极通过交替配置的导电剂，这可以很容易地采用在国家的最先进的电池制造工艺。
Increasing areal active material loading by thick electrodes is a direct and effective approach to improve the energy density of lithium-ion batteries (LIBs). However, it may also induce large polarization effects and reduce the active material utilization, especially under high charge/discharge current densities. In this work, dual-layered LiNi0.8Co0.15Al0.05O2(NCA) cathodes with high areal capacity of about 5 mAh/cm2and gradient porosity are prepared via a layer-by-layer method, in which carbon nanotubes (CNTs) and Super P (SP) carbon are used to build the electron conducting networks as well as to adjust the porosity. It is demonstrated that the CNT-SP cathode, which uses CNTs as the conductive agent in the lower layer (close to the current collector) and SP as the conductive agent in the upper layer (close to the separator), provides the highest areal capacity of 4.81 mAh/cm2among all configurations studied (CNT-SP, SP-SP, SP-CNT, and CNT-CNT). And it exhibits high capacity retention of 99.5% over 100 cycles in NCA||graphite full pouch cells at current density of 0.2 C rate. The excellent performance of the thick CNT-SP cathode is attributed to the construction of favorable conductive networks which can provide effective and reliable paths for electron transport and Li+diffusion. Moreover, a thinner electrode/electrolyte interphase layer is found to form in the CNT-SP electrode. This research reveals a viable approach for ameliorating the significant polarization effects and limited active material utilization in thick electrodes through alternate configurations of the conductive agents, which can be easily adopted in state-of-the-art battery manufacturing processes.
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影响因子：
9.4
作者：
Li-Chun Chen;Darjen Liu;Ta‐Jo Liu;C. Tiu;C. Yang;Wen-bing Chu;C. Wan
通讯作者：
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影响因子：
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作者：
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通讯作者：
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影响因子：
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作者：
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通讯作者：
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影响因子：
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作者：
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通讯作者：
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