Single-component slurry based lithium-ion flow battery with 3D current collectors

Slurry based lithium-ion flow battery is a promising technology to improve the energy density of redox flow batteries for various applications. However, the high viscosity and flow resistance of slurry increase the pumping loss and limit the volume ratio of active materials, which hinders its further improvement in energy density. Here we propose a concept of single-component slurry based lithium-ion flow battery by utilizing carbon felt as the 3D current collector. The single-component slurry, consisting of lithium intercalation particles and electrolyte, can significantly decrease the slurry viscosity due to elimination of adding discrete carbon particles, enabling an increase in the volume ratio of active materials to further improve volumetric capacity and energy density of the lithium-ion flow battery. The demonstrated low-viscosity lithium iron phosphate slurry based battery achieves an energy density of 230 Wh L−1 and coulombic efficiency >95% over 100 cycles in a coin cell and good stability in flow-cell tests for both intermittent and continuous flow modes. The concept may offer a new opportunity for slurry based flow battery to minimize the viscosity and maximize the volumetric capacity. [Display omitted] •Single-component slurry lithium-ion flow battery with porous collector is proposed.•Performance of carbon papers, clothes and felts as current collectors is evaluated.•LFP slurry shows high energy density (230 Wh L−1) and coulombic efficiency (>95%).•Cycling characteristics of single-component LFP slurry in a flow cell is revealed.