As one common industrial waste liquid, waste copper (Cu) etchant can seriously pollute the environment if it is unreasonably managed. Herein, tetrahedron-like copper (I) chloride (CuCl) crystals were extracted from waste copper etchant by way of facile electrodeposition, and the effect of the electrodeposition time on the lithium (Li)-storage capacity of the copper (I) chloride crystal was further investigated. The results showed that the copper (I) chloride crystal had a regular tetrahedral morphology, and the density of the regular tetrahedral particles gradually increased with the extension of the electrodeposition time from 5 to 15, 20 and 25 s. Correspondingly, the reversible lithium-storage capacity of the copper (I) chloride anode experienced an initial increase and a subsequent decrease. In detail, when cycling at 2 C for 250 cycles, the reversible discharge capacity of the copper (I) chloride anode increased from 187·3 mAh/g at 5 s to 284·5 mAh/g at 15 s and then decreased to 191·9 mAh/g at 20 s and to 125·3 mAh/g at 25 s, indicating that 15 s may be the most optimal electrodeposition time. Excessive copper (I) chloride particles may result in poor performance due to the poor inherent conductivity of copper (I) chloride. Such efforts would alleviate environmental pollution and facilitate the circular economy of wastes.

中文翻译：

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电沉积时间对废铜蚀刻剂对CuCl阳极的影响

作为一种常见的工业废液，如果管理不当，废铜（Cu）蚀刻剂会严重污染环境。在此，通过简便的电沉积从废铜蚀刻剂中提取出四面体状的氯化铜（CuCl）晶体，以及电沉积时间对氯化铜（I）晶体的锂（Li）存储容量的影响进一步调查。结果表明，氯化铜（I）晶体具有规则的四面体形态，并且规则的四面体颗粒的密度随着电沉积时间的延长从5到15、20和25 s逐渐增加。相应地，氯化铜（I）阳极的可逆锂储存容量经历了初始增加和随后的减少。详细地说，在2 C下循环250个循环时，氯化铜阳极的可逆放电容量从5 s时的187·3 mAh / g增加到15 s时的284·5 mAh / g，然后在20 s时降低至191·9 mAh / g，然后降低至125· 25 s时为3 mAh / g，表明15 s可能是最佳的电沉积时间。氯化铜（I）过多会由于氯化铜（I）固有的导电性差而导致性能下降。这些努力将减轻环境污染，促进废物循环经济。氯化铜（I）过多会由于氯化铜（I）固有的导电性差而导致性能下降。这些努力将减轻环境污染，促进废物循环经济。氯化铜（I）过多会由于氯化铜（I）固有的导电性差而导致性能下降。这些努力将减轻环境污染，促进废物循环经济。