Unlocking Reversible Silicon Redox for High‐Performing Chlorine Batteries

Abstract

Chlorine (Cl)‐based batteries such as Li/Cl2 batteries are recognized as promising candidates for energy storage with low cost and high performance. However, the current use of Li metal anodes in Cl‐based batteries has raised serious concerns regarding safety, cost, and production complexity. More importantly, the well‐documented parasitic reactions between Li metal and Cl‐based electrolytes require a large excess of Li metal, which inevitably sacrifices the electrochemical performance of the full cell. Therefore, it is crucial but challenging to establish new anode chemistry, particularly with electrochemical reversibility, for Cl‐based batteries. Here we show, for the first time, reversible Si redox in Cl‐based batteries through efficient electrolyte dilution and anode/electrolyte interface passivation using 1,2‐dichloroethane and cyclized polyacrylonitrile as key mediators. Our Si anode chemistry enables significantly increased cycling stability and shelf lives compared with conventional Li metal anodes. It also avoids the use of a large excess of anode materials, thus enabling the first rechargeable Cl2 full battery with remarkable energy and power densities of 809 Wh kg−1 and 4,277 W kg−1, respectively. The Si anode chemistry affords fast kinetics with remarkable rate capability and low‐temperature electrochemical performance, indicating its great potential in practical applications.

Revitalizing Chlorine–Based Batteries for Low–Cost and High–Performance Energy Storage

“…Recently, we unlocked reversible Si redox in Cl-based batteries based on a 'dilution-passivation' effect, i.e., electrolyte dilution and anode-electrolyte interface passivation using 1,2-dichloroethane (DCE) and cyclized polyacrylonitrile (PAN), respectively, achieving the first rechargeable Cl 2 full battery with a controlled anode capacity of ≈2.5 mAh cm -2 (Figure 13a). [96] The Li-Si-C/Cl 2 (named LSC/Cl 2 ) battery exhibited significantly batter electrochemical stability compared to the Li/Cl 2 battery (Figure 13b). In addition, it showed an average CE of ≈98% over more than 250 cycles at 500 mA g −1 (Figure 13c).…”

“…Based on the total mass of the [96] The synergistic design of electrolyte dilution and anode/electrolyte interface passivation is critical to realize reversible Li-Si alloying/dealloying reactions in Cl-based electrolytes. [96] b) Variations of the open-circuit voltage for LSC/Cl 2 and Li/Cl 2 batteries using the Cl-based electrolyte with and without DCE diluent (named ALS-90%DCE and ALS, respectively). [96] c) Comparison of the cycling performance of LSC/Cl 2 and Li/Cl 2 batteries using ALS-90%DCE electrolyte.…”

“…[96] b) Variations of the open-circuit voltage for LSC/Cl 2 and Li/Cl 2 batteries using the Cl-based electrolyte with and without DCE diluent (named ALS-90%DCE and ALS, respectively). [96] c) Comparison of the cycling performance of LSC/Cl 2 and Li/Cl 2 batteries using ALS-90%DCE electrolyte. The specific charge capacity and current density were 500 mAh g −1 and 500 mA g −1 , respectively.…”

Enrichment of Chlorine in Porous Organic Nanocages for High-Performance Rechargeable Lithium–Chlorine Batteries

“…Recently, there has been an urgent pursuit of high-energy-density battery systems due to the rapid growth of electric vehicles and electronic products. − Rechargeable Li–Cl 2 batteries gradually attract people’s attention owing to their high energy density. − This kind of battery mainly consists of a Li/Li + negative electrode, a Cl – /Cl 2 positive electrode, and a SOCl 2 -based electrolyte, which could deliver a high discharge voltage of ∼3.5 V. However, cycling a Li–Cl 2 cell at a high specific capacity is still challenging, which restricts the energy density of the Li–Cl 2 battery. An important reason causing the failure of the Li–Cl 2 cell at a high cycling capacity is the insufficient supply of Cl 2 to the electrochemical reaction due to the weak interaction between cathode materials and Cl 2 molecules.…”

Rechargeable Hydrogen–Chlorine Battery Operates in a Wide Temperature Range

“…Some progress has been made recently in activating the Cl 2 /Cl – redox in nonaqueous electrolytes initiating from the rechargeable Li/Na–Cl 2 battery reported by Dai et al, − as well as the flow batteries based on solvents with high Cl 2 solubility like carbon tetrachloride . In contrast, aqueous Cl 2 -based batteries offer advantages of ecofriendliness, enhanced safety, and high-rate capability, which have not been thoroughly investigated.…”