Assembling and Performance comparision of Different cathode chemistries utilized in all-solid-state lithium-sulfur batteries

Solid

electrolytes are considered to be utilized in next generation lithium-ion

battery systems. Compared to conventional lithium-ion batteries, these systems

enables cells with higher energy density along with free of flammability risks.

Among various kind of solid-electrolytes, sulfur based electrolytes are

promising to be adopted into lithium-ion batteries by virtue of their high

ionic conductivity on the order of liquid electrolytes.<o:p></o:p>

Sulfur is at the

focus of lithium-sulfur batteries with its theoretical capacity of 1672 mAh/gr.

Yet challenges arising from the insulating nature of sulfur and well-known

polysulfide shuttle problem hindered its adoption into batteries capable of

long cycling. However, studies showed that cell chemistry of solid-state lithium-sulfur

batteries are different from conventional cells utilizing liquid organic

electrolytes which eliminates the formation of polysulfides.<o:p></o:p>

In this study,

we constructed all solid-state lithium-ion battery (ASSLIB) where lithium and

Li7P3S11 utilized as anode and solid

electrolyte respectively. We first checked the compatibility of

anode-electrolyte interface through chronoamperometry and chronopotentiometry

techniques. Then, sulfur based quaternary composite cathodes were synthesized

through three distinct chemistries namely, melt-quenching method, sulfur-amine

chemistry and sulfur-reduction from Na2S2O3.

Electrochemical performance of different cathode chemistries were compared. Our

results indicate that ASSLIBs assembled with cathode utilizing Na2S2O3

reduced sulfur showed best electrochemical performance and cycling. We have

proposed the underlying mechanism as the smaller and uniform sulfur

distribution enabled by reduction chemistry which facilitates better charge transfer

at the cathode. We have also argued the performance limits and bottlenecks of batteries constructed with liquid and solid

electrolytes having same cathode chemistries.<o:p></o:p>