The anodic stability and reversibility of Ca metal electrodeposition/dissolution have always been hampered by surface passivation and anion corrosion,especially in F-based carbonate ester electrolytes at high device v...The anodic stability and reversibility of Ca metal electrodeposition/dissolution have always been hampered by surface passivation and anion corrosion,especially in F-based carbonate ester electrolytes at high device voltages.To avoid direct Ca metal/electrolyte reactions,an artificial hybrid solid electrolyte layer(AHSEL),which is characteristic of sodium/calcium carbonate and calcium hydride nitride nanocrystals of size<10 nm encapsulated by amorphous C,N species,is constructed on calcium with good ion conductivity(≈0.01 mS cm^(-1))and uniform coating of thickness≈20μm.After cycling in the KPF_(6) electrolyte,AHSEL is transformed into Na/K/Ca hybrid solid electrolyte interphases(SEIs),which is a compact layer composed of monodisperse nanocrystals(mostly Ca_(2)NH)and small amorphous zones,thus greatly suppressing the fluoridation of the Ca deposit.Consequently,the plating/stripping performance of AHSEL-modified Ca(AHSEL-Ca)is markedly improved compared with that of pristine Ca,lasting for>1400 h at a polarization shift of<0.4 mV/h.The AHSEL-Ca anode also endows Ca batteries with superior anodic stability with a ceiling voltage of up to 5.0 V,a high discharge voltage(>3.3 V),a large capacity of≈80 mAh g^(-1)at 200 mA g^(-1),and an ultralong lifespan≈5000 cycles.展开更多
Owing to its low potential, crustal abundances and environmental friendliness, calcium metal anode(CMA) is emerging as a powerful contender in post-lithium era. However, the passivation of CMA fatally hinders its deve...Owing to its low potential, crustal abundances and environmental friendliness, calcium metal anode(CMA) is emerging as a powerful contender in post-lithium era. However, the passivation of CMA fatally hinders its development. Recently, several feasible electrolytes have been developed. Nevertheless, as a pivotal part, the solid electrolyte interface(SEI) formed on CMA has not been paid enough attention to. In this review, based on the passivation mechanism of CMA, the favorable composition of SEI is emphasized with the corresponding electrolytes. It is considered that boron-containing and organic–inorganic hybrid SEI might be preferred. By comparing electrolytes and SEI on CMA with lithium and magnesium metal anodes, the root causes of CMA passivation are further elaborated, enlightening rational design rules of suitable SEI. Furthermore, some noteworthy details when assembling secondary calcium metal batteries(CMBs) are put forward. It is expected that deeper understanding of SEI on CMA will promote the development of CMBs.展开更多
基金support from the National Natural Science Foundation of China(Nos.51872339,91963210,and U1801255)the Key Research and Development Program of Guangdong Province(No.2020B0101690001)。
文摘The anodic stability and reversibility of Ca metal electrodeposition/dissolution have always been hampered by surface passivation and anion corrosion,especially in F-based carbonate ester electrolytes at high device voltages.To avoid direct Ca metal/electrolyte reactions,an artificial hybrid solid electrolyte layer(AHSEL),which is characteristic of sodium/calcium carbonate and calcium hydride nitride nanocrystals of size<10 nm encapsulated by amorphous C,N species,is constructed on calcium with good ion conductivity(≈0.01 mS cm^(-1))and uniform coating of thickness≈20μm.After cycling in the KPF_(6) electrolyte,AHSEL is transformed into Na/K/Ca hybrid solid electrolyte interphases(SEIs),which is a compact layer composed of monodisperse nanocrystals(mostly Ca_(2)NH)and small amorphous zones,thus greatly suppressing the fluoridation of the Ca deposit.Consequently,the plating/stripping performance of AHSEL-modified Ca(AHSEL-Ca)is markedly improved compared with that of pristine Ca,lasting for>1400 h at a polarization shift of<0.4 mV/h.The AHSEL-Ca anode also endows Ca batteries with superior anodic stability with a ceiling voltage of up to 5.0 V,a high discharge voltage(>3.3 V),a large capacity of≈80 mAh g^(-1)at 200 mA g^(-1),and an ultralong lifespan≈5000 cycles.
基金supported by the National Natural Science Foundation of China(51872196)the Natural Science Foundation of Tianjin,China(17JCJQJC44100)。
文摘Owing to its low potential, crustal abundances and environmental friendliness, calcium metal anode(CMA) is emerging as a powerful contender in post-lithium era. However, the passivation of CMA fatally hinders its development. Recently, several feasible electrolytes have been developed. Nevertheless, as a pivotal part, the solid electrolyte interface(SEI) formed on CMA has not been paid enough attention to. In this review, based on the passivation mechanism of CMA, the favorable composition of SEI is emphasized with the corresponding electrolytes. It is considered that boron-containing and organic–inorganic hybrid SEI might be preferred. By comparing electrolytes and SEI on CMA with lithium and magnesium metal anodes, the root causes of CMA passivation are further elaborated, enlightening rational design rules of suitable SEI. Furthermore, some noteworthy details when assembling secondary calcium metal batteries(CMBs) are put forward. It is expected that deeper understanding of SEI on CMA will promote the development of CMBs.
