Facile Separator Modification Strategy for Trapping Soluble Polyphosphides and Enhancing the Electrochemical Performance of Phosphorus Anode

Abstract

Phosphorus anode is one of the most promising candidates for high-energy-density lithium-ion batteries. Recent studies found the lithiation process of phosphorus is accompanied by the soluble intermediates of lithium polyphosphides. The trans-separator diffusion of polyphosphides is responsible for the capacity decay. Herein, a facile separator modification strategy is proposed for improving the performance of phosphorus anode. The lightweight CNT-modified layer that has a continuous conductive skeleton, a dense structure, and a strong interaction with the soluble lithium polyphosphides can trap, stabilize, and reactivate the active material. Without sophisticated electrode structure design, the cyclability and high-rate performance of the phosphorus anode has been significantly improved, leading to a higher specific capacity of 1505 mAh/g at 250 mA/g (200th cycle) and 1312 mAh/g at 2 A/g. With the advantages of simplicity and low cost, the separator modification strategy provides a new feasible way for further improvement of the phosphorus-based anode.

Bi Works as a Li Reservoir for Promoting the Fast‐Charging Performance of Phosphorus Anode for Li‐Ion Batteries

“…The binding energies (E b ) of polyphosphides (LiP 7 and LiP 5 ) [13,40] with Bi or LiBi were calculated by density functional theory, respectively, as shown in Figure 5h and Figure S20 (Supporting Information). Both Bi and LiBi offer high adsorption energy for LiP 7 and LiP 5 .…”

Phosphorus‐Based Anodes for Fast Charging Lithium‐Ion Batteries: Challenges and Opportunities

“…Therefore, new methods to enable efficient bonding of P and C need to be developed. Moreover, most recent research results have shown that the lithium polyphosphide intermediates may be soluble in electrolyte, [ 80 ] which may accelerate capacity fading upon cycling. Finally, the high P content also increases SEI generation, which affects both Li‐ion diffusion and electron conductivity.…”

Constructing a Micrometer-Sized Structure through an Initial Electrochemical Process for Ultrahigh-Performance Li+ Storage

“…A direct approach is the application of other electrode materials with higher specific capacity in comparison to the current commercial LIB electrode, such as a manganese-rich layered oxide for the cathode as well as Si, Sn, and P for the anode, and many impressive results have been reported presently. Sun et al employed a lightweight CNT-modified layer to capture the soluble lithium polyphosphide, leading to a high specific capacity of 1505 mAh g –1 at 250 mA g –1 (200th cycle) and 1312 mAh g –1 at 2 A g –1 . Amine et al found that Mn substitution can effectively alleviate the destructive effects of Co and demonstrated a series of promising Co-free cathodes .…”