Ni Jiangfeng, Li Xinyan, Sun Menglei, Yuan Yifei, Liu Tongchao, Li Liang, Lu Jun
School of Physical Science and Technology, Center for Energy Conversion Materials & Physics (CECMP), Soochow University, Suzhou 215006, People's Republic of China.
Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, United States.
ACS Nano. 2020 Jul 28;14(7):9117-9124. doi: 10.1021/acsnano.0c04366. Epub 2020 Jul 1.
Sodium-ion batteries have attracted widespread attention for cost-effective and large-scale electric energy storage. However, their practical deployment has been largely retarded by the lack of choice of efficient anode materials featuring large capacity and electrochemical stability and robustness. Herein, we report a durian-inspired design and template-free fabrication of a robust sodium anode based on triangular pyramid arrays of BiSb alloy electrodeposited on Cu substrates. The BiSb arrays exhibit an appreciable electrochemical robustness for sodium storage, sustaining a reversible capability 335 mAh g at a high rate of 2.5 A g and 87% of the initial capacity over 2000 cycles. We further demonstrate the applicability of the BiSb array anode in sodium full cells by pairing it with a NaV(PO)/C cathode. This full cell achieves a high specific energy of 203 Wh kg (based on both active electrodes). Such an enhanced performance is attributed to the thorny-durian-like architecture and bimetallic alloy composition. The pyramid tip induces ion enrichment for rapid charge-transfer reaction, while the alloy design reduces the electrode volume swelling for stable Na cycling.
钠离子电池因其具有成本效益且适用于大规模电能存储而受到广泛关注。然而，由于缺乏兼具大容量、电化学稳定性和坚固性的高效阳极材料，其实际应用在很大程度上受到了阻碍。在此，我们报告了一种受榴莲启发的设计，并在无模板的情况下制造了一种坚固的钠阳极，该阳极基于电沉积在铜基板上的BiSb合金三角锥阵列。BiSb阵列在储钠方面表现出可观的电化学坚固性，在2.5 A g的高电流密度下保持335 mAh g的可逆容量，并在2000次循环后保持初始容量的87%。我们进一步通过将BiSb阵列阳极与NaV(PO)/C阴极配对，证明了其在钠全电池中的适用性。这种全电池实现了203 Wh kg的高比能量（基于两个活性电极）。这种性能的提升归因于类似榴莲刺的结构和双金属合金成分。金字塔尖端促使离子富集以进行快速电荷转移反应，而合金设计减少了电极体积膨胀，从而实现稳定的钠循环。
