In Situ Partial Pyrolysis of Sodium Carboxymethyl Cellulose Constructing Hierarchical Pores in the Silicon Anode for Lithium-Ion Batteries

Silicon is an attractive anode material for the high-energy-density lithium-ion battery due to its high theoretical capacity (4200 mA h g–1). However, larger volume expansion (∼300%) and pulverization during cycling hinder the commercialization of silicon anodes. The modification of silicon materials is a widely recognized approach to enhance the anode performance, but the volume expansion cannot be solved completely when only focusing on the active material but ignoring the overall structural optimization of the anode. In the study, additional hierarchical pores were constructed in the electrodes by in situ partial pyrolysis of the binder sodium carboxymethyl cellulose (CMC) at low temperature. Benefiting from the extra buffer space, the electrodes can accommodate more expansion and enhance the conduction of electrons and ions. In addition, the partially degraded CMC reduced the adsorption energy between the binder and the active material, reducing the stress during the swelling process, which is demonstrated by density functional theory. The as-obtained electrode delivered a high reversible capacity of 1035 mA h g–1 at 1000 mA g–1, while the capacity retention was 78.7%, and the Coulombic efficiency was stable at 99.3% after 200 cycles. The modification of the electrode structure provides guidance for the construction of high-efficiency anodes

Double-Faced Bond Coupling to Induce an Ultrastable Lithium/Li₆PS₅Cl Interface for High-Performance All-Solid-State Batteries

Sulfide-type solid electrolytes (SSEs) are supposed to be preferential candidates for all-solid-state Li metal batteries (ASSLMBs) due to their satisfactory Li+ conductivity and preferable mechanical stiffness. Nonetheless, the poor stability between the Li anode and SSEs and uncontrolled Li dendrite growth severely restrict their commercial application. Herein, an amphiphilic LixSiOy-enriched solid electrolyte interphase (SEI) as a “Janus” layer was first introduced at the Li/SSEs interface, and it exhibited bond coupling reactivity with both the Li anode and SSEs by forming Li–S, Li–O–Si, and Si–S covalent bonds, which is called the pincer effect. In addition to the physical isolation of Li and SSEs to prevent side reactions between them, LixSiOy with high ionic conductivity offers abundant and evenly distributed transport channels for fast Li+ migration. As evidenced by in situ microscopy, the high-strength anodic interface constructed by the pincer effect and in situ decomposition mentioned above is free from mechanical damage during the Li plating/stripping. As a result, the symmetric cells exert an outstanding cycling performance for over 2000 h at 0.2 mA cm–2 and even 500 h at 0.5 mA cm–2 without evident resistance growth. The artificial SEI layer with the pincer effect and its effective application in interfacial stabilization put forward a new perspective for the commercialization of ASSLMBs

Double-Faced Bond Coupling to Induce an Ultrastable Lithium/Li₆PS₅Cl Interface for High-Performance All-Solid-State Batteries

Sulfide-type solid electrolytes (SSEs) are supposed to be preferential candidates for all-solid-state Li metal batteries (ASSLMBs) due to their satisfactory Li+ conductivity and preferable mechanical stiffness. Nonetheless, the poor stability between the Li anode and SSEs and uncontrolled Li dendrite growth severely restrict their commercial application. Herein, an amphiphilic LixSiOy-enriched solid electrolyte interphase (SEI) as a “Janus” layer was first introduced at the Li/SSEs interface, and it exhibited bond coupling reactivity with both the Li anode and SSEs by forming Li–S, Li–O–Si, and Si–S covalent bonds, which is called the pincer effect. In addition to the physical isolation of Li and SSEs to prevent side reactions between them, LixSiOy with high ionic conductivity offers abundant and evenly distributed transport channels for fast Li+ migration. As evidenced by in situ microscopy, the high-strength anodic interface constructed by the pincer effect and in situ decomposition mentioned above is free from mechanical damage during the Li plating/stripping. As a result, the symmetric cells exert an outstanding cycling performance for over 2000 h at 0.2 mA cm–2 and even 500 h at 0.5 mA cm–2 without evident resistance growth. The artificial SEI layer with the pincer effect and its effective application in interfacial stabilization put forward a new perspective for the commercialization of ASSLMBs

Double-Faced Bond Coupling to Induce an Ultrastable Lithium/Li₆PS₅Cl Interface for High-Performance All-Solid-State Batteries

Sulfide-type solid electrolytes (SSEs) are supposed to be preferential candidates for all-solid-state Li metal batteries (ASSLMBs) due to their satisfactory Li+ conductivity and preferable mechanical stiffness. Nonetheless, the poor stability between the Li anode and SSEs and uncontrolled Li dendrite growth severely restrict their commercial application. Herein, an amphiphilic LixSiOy-enriched solid electrolyte interphase (SEI) as a “Janus” layer was first introduced at the Li/SSEs interface, and it exhibited bond coupling reactivity with both the Li anode and SSEs by forming Li–S, Li–O–Si, and Si–S covalent bonds, which is called the pincer effect. In addition to the physical isolation of Li and SSEs to prevent side reactions between them, LixSiOy with high ionic conductivity offers abundant and evenly distributed transport channels for fast Li+ migration. As evidenced by in situ microscopy, the high-strength anodic interface constructed by the pincer effect and in situ decomposition mentioned above is free from mechanical damage during the Li plating/stripping. As a result, the symmetric cells exert an outstanding cycling performance for over 2000 h at 0.2 mA cm–2 and even 500 h at 0.5 mA cm–2 without evident resistance growth. The artificial SEI layer with the pincer effect and its effective application in interfacial stabilization put forward a new perspective for the commercialization of ASSLMBs

Double-Faced Bond Coupling to Induce an Ultrastable Lithium/Li₆PS₅Cl Interface for High-Performance All-Solid-State Batteries

Sulfide-type solid electrolytes (SSEs) are supposed to be preferential candidates for all-solid-state Li metal batteries (ASSLMBs) due to their satisfactory Li+ conductivity and preferable mechanical stiffness. Nonetheless, the poor stability between the Li anode and SSEs and uncontrolled Li dendrite growth severely restrict their commercial application. Herein, an amphiphilic LixSiOy-enriched solid electrolyte interphase (SEI) as a “Janus” layer was first introduced at the Li/SSEs interface, and it exhibited bond coupling reactivity with both the Li anode and SSEs by forming Li–S, Li–O–Si, and Si–S covalent bonds, which is called the pincer effect. In addition to the physical isolation of Li and SSEs to prevent side reactions between them, LixSiOy with high ionic conductivity offers abundant and evenly distributed transport channels for fast Li+ migration. As evidenced by in situ microscopy, the high-strength anodic interface constructed by the pincer effect and in situ decomposition mentioned above is free from mechanical damage during the Li plating/stripping. As a result, the symmetric cells exert an outstanding cycling performance for over 2000 h at 0.2 mA cm–2 and even 500 h at 0.5 mA cm–2 without evident resistance growth. The artificial SEI layer with the pincer effect and its effective application in interfacial stabilization put forward a new perspective for the commercialization of ASSLMBs