Control of crystallography of thin metal electrodeposit films has recently emerged as key to achieving long operating lifetimes in next-generation electrochemical systems for energy storage. Very recent studies show that the crystallography of metal deposits impacts both morphological evolution and chemical kinetics of the interfaces between metal anodes and electrolytes in a battery. We report that the large crystallographic heterogeneity, e.g., broad orientational distribution, that appears characteristic of commercial metal foils results in rough morphology upon plating/stripping. On this basis, we develop an accumulative roll bonding (ARB) methodology—a severe plastic deformation process—that uses commercial metal foils as input. Zn metal—a promising, low-cost-competitive battery anode material— is used as a first example to interrogate the proposed concept. We demonstrate that the ARB process is highly effective in achieving uniform, mono-domain quality crystallographic control on macroscopic materials. After the ARB process, the Zn grains exhibit a strong (002) texture (i.e. [002]_Zn//ND). We report further that the texture transitions from a classical bipolar pattern to a nonclassical unipolar pattern under large nominal strain, almost completely eliminating the orientational heterogeneity of the foil. Evaluated as anodes in aqueous Zn coin cells, the strongly (002)-textured Zn suppresses the rough plating/stripping landscape, promotes uniform, homoepitaxial growth of Zn and remarkably improve the continuous plating/stripping performance by nearly two orders of magnitude under practical conditions (e.g., 4 mAh at 40 mA/cm²). The performance improvements are readily scaled to achieve pouch-type Zn full batteries that deliver exceptional reversibility. The ARB process is thermo-mechanical and can in principle be applied to any metal chemistry to achieve similar crystallographic uniformity, provided the appropriate temperature and accumulated strains are employed to achieve severe levels of plastic deformation. We evaluate this concept using ARB to induce strong texturing phenomena in commercial Li and Na foils, which unlike Zn (HCP) are BCC crystals, and demonstrate its success using morphological and electrochemical analysis of these metals as electrodes. Our simple process for creating strong textures in both hexagonal and cubic metals and illustrating the critical role such built-in crystallography plays underscores potentially transformative opportunities for developing scalable, highly reversible thin metal anodes (e.g. hexagonal Zn, Mg, and cubic Li, Na, Ca, Al) with specific crystal textures for next generation batteries that have practical N:P ratios.

Key References:

Zheng, J., et al. Advanced Materials 34.1 (2022): 2106867.

Zheng, J., et al. Nature Energy 6.4 (2021): 398-406.

Zheng, J., et al. Science Advances 6.25 (2020): eabb1122

Zheng, J., et al. Science 366.6465 (2019): 645-648.