A tailored highly solvating electrolyte toward ultra lean-electrolyte Li-S batteries  

作　　者：Zixiong Shi Simil Thomas Zhengnan Tian Dong Guo Zhiming Zhao Yizhou Wang Shuo Li Nimer Wehbe Abdul-Hamid Emwas Osman M.Bakr Omar F.Mohammed Husam N.Alshareef 

机构地区：[1]Materials Science and Engineering,Division of Physical Sciences and Engineering,King Abdullah University of Science and Technology(KAUST),Thuwal 23955-6900,Saudi Arabia [2]Advanced Membranes and Porous Materials Center(AMPMC),King Abdullah University of Science and Technology(KAUST),Thuwal 23955-6900,Saudi Arabia [3]Core Labs,King Abdullah University of Science and Technology(KAUST),Thuwal 23955-6900,Saudi Arabia

出　　处：《Nano Research Energy》2024年第4期43-56,共14页纳米能源研究(英文)

基　　金：King Abdullah University of Science and Technology(KAUST).

摘　　要：Low electrolyte usage is a key to attaining high-energy-density lithium–sulfur(Li–S)batteries.However,this is still a tremendous challenge for traditional ether-based electrolytes that follow a dissolution–precipitation mechanism.Highly solvating electrolytes,which can facilitate polysulfide dissolution and alter reaction pathway,are considered a promising strategy.Nonetheless,mechanistic understanding and kinetic evaluation remain insufficient while the principle of Li_(2)S nucleation and dissociation has not been elucidated.Herein,we unveil the Li-ion solvation and polysulfide speciation in the solvents with different denticity and donicity.The origin of S_(3)^(•–)radical-directed path and three-dimensional Li_(2)S precipitation in high-donicity electrolytes has been uncovered.It is revealed that ammonium ions enable the facile dissolution and dissociation of Li_(2)S via Lewis acid-base interaction and H···S^(2–)binding.Consequently,Li–S batteries with a low electrolyte and sulfur(E/S)ratio of 5μL·mgs^(-1) achieve a high capacity of 1092 mAh·g^(-1).Even at a harsh E/S ratio of 3μL·mgs^(-1) and a high sulfur loading of 4 mg·cm^(-2),they still sustain a stable operation over 30 cycles.Our work sheds light on the underlying reaction mechanism and rationalizes the design of highly solvating electrolytes,which in turn opens a new avenue for achieving pragmatic lean-electrolyte Li–S batteries.

关 键 词：donicity S_(3)^(•–)radical Li_(2)S dissociation lean-electrolyte Li–S batteries 

分 类 号：TM9[电气工程—电力电子与电力传动]