反其道而行之:利用尖端效应构筑3D耦合电极实现锌基液流电池超高面容量与长循环寿命(英文)

Act in contravention:a non-planar coupled electrode design utilizing‘‘tip effect”for ultra-high areal capacity,long cycle life zinc-based batteries

水系锌基电池在商业化储能设备中的应用潜力巨大,但锌负极在高面容量下较差的循环稳定性限制了其进一步发展.该文提出了一种用于水系锌基电池的平顶金字塔形耦合电极结构.得益于其微观及宏观的3D结构,该电极能够有效增加锌沉积位点,调整锌沉积形貌,优化电池中电场和电解液流场分布,还可以为锌提供必要的沉积空间.此外,通过利用"尖端效应",这种正负极耦合交错使用的电极结构可以将锌枝晶的位置精确地控制在金字塔尖端,有效降低了电池短路的风险.使用这种电极组装的锌碘液流电池可在40 mA cm-2的高电流密度下实现240 m Ah cm-2的超高面容量,并能以160 m Ah cm-2的高面容量稳定循环300次以上.该电极结构设计为解决锌负极高面容量的问题提供了一个有效对策,对高能量密度、长寿命水系锌基电池的发展起到推动作用.

Aqueous zinc-based batteries(ZBBs)have great potential as commercial energy storage devices.However,the poor cycling stability of zinc anode under high areal capacity limits their further application.Herein,a coupled non-planar electrode design achieved by the tailored flat-top pyramid carbon felt(TCF)is proposed for ZBBs,which can effectively increase the zinc deposition sites,adjust the deposition morphology,optimize the current and electrolyte flow velocity distribution and provide necessary space for zinc plating.Interestingly,by utilizing "tip effect",the coupled TCFs enable precise control of the zinc dendrite growth position,effectively reducing the risk of short circuit.Based on such coupled TCFs,zinciodine flow batteries can deliver an ultra-high areal capacity of 240 m Ah cm^(-2) and a superb cycling stability over 300 cycles(areal capacity of 160 m Ah cm^(-2))at a high current density of 40 m A cm^(-2).Therefore,we provide an effective strategy for high areal capacity zinc anode design,which may promote the development of high energy density and long cycle life ZBBs.