Constructing an Expandable Molecular Chain as a Functionalized Flexible Matrix to Achieve Lithium-Free Anode

Abstract

Lithium metal has been considered the most ideal choice for the anode in rechargeable high energy density batteries. Direct metal anode is a plating/stripping process without any self-supporting framework, thus making the metal electrodes susceptible to collapse and difficult for the repeating processes. Herein, we construct a stretchable molecular chain as a flexible skeleton to achieve the lithium repeated plating/stripping. The Cu_xS-In₂S₃ can in situ be converted into lithiophilic LixIny and Li₂S composites during the lithium deposition process in which an “expandable molecule chains” is formed through the S connections. Once formed, the lithiophilic chains remain existing stable but just their upright state changes thus serving as a functionalized flexible matrix (FFM) for the lithium dissolution and deposition process. Benefiting from these features, the anode-free full cells FFM||LFP display superior cycling stability and long lifespan, with a high-capacity retention of 86.7 % at 0.2 C-rate after 100 cycles. These explorations provide new strategies for developing high-performance ‘Anode-free’ lithium metal battary (AFLMB).