Limited lithium supply is hindering the global transformation towards electrification and decarbonization. Current lithium mining can be energy, chemical and land intensive. Here we present an efficient and self-concentrating crystallization method for the selective extraction of lithium from both brine and seawater. The sequential and separable crystallization of cation species with different concentrations and solubilities was enabled by a twisted and slender 3D porous natural cellulose fibre structure via capillary and evaporative flows. The process exhibited an evaporation rate as high as 9.8 kg m⁻² h⁻¹, and it selectively concentrated lithium by orders of magnitude. The composition and spatial distribution of crystals were characterized, and a transport model deciphered the ion re-distribution process in situ. We also demonstrated system scalability via a 100-crystallizer array.

锂供应有限正在阻碍全球电气化和脱碳转型。目前的锂矿开采属于能源、化学和土地密集型。在这里，我们提出了一种有效的自浓缩结晶方法，用于从盐水和海水中选择性提取锂。扭曲细长的 3D 多孔天然纤维素纤维结构通过毛细管和蒸发流实现了不同浓度和溶解度的阳离子物种的连续且可分离的结晶。该过程的蒸发速率高达 9.8 kg m ^{− 2}  h ⁻¹，并且它选择性地将锂浓缩了几个数量级。对晶体的组成和空间分布进行了表征，并用输运模型解释了离子在原位的重新分布过程。我们还通过 100 个结晶器阵列展示了系统的可扩展性。