Structured electrolytes to suppress dendrite growth in high energy density batteries

Abstract

Dendrite formation on the anode surface of high energy density lithium batteries is closely related to the safety and capacity of batteries; therefore, the suppression of dendrite growth could significantly improve battery performance and lifetime. Many reports demonstrate the close relation between local mass transport and dendrite growth, and most of the research focuses on improving the transport properties of isotropic electrolytes (electrolytes with a uniform diffusion coefficient). Recent research reveals strong dendrite suppression effects with anisotropic electrolytes which have a directional diffusivity; however applying anisotropic electrolytes to existing battery systems is challenging. In this paper we propose several hybrid structured electrolyte designs which can generate local non-uniform mass transport properties and induce dendrite suppression effects while still using conventional isotropic electrolytes. A numerical study is done to consider three hybrid electrolyte designs and shows that using a columnized solid structure with a typical isotropic liquid electrolyte can significantly suppress dendrite growth without sacrificing battery performance. The effects of the columnized hybrid electrolyte compare well with experimental data and suggest that through careful design of a columnar structure the benefits of an anisotropic electrolyte can be achieved without the need for developing new anisotropic liquid electrolytes. Copyright © 2016 John Wiley & Sons, Ltd.