All organic compounds with active sites for lithiation can be used as electrode materials for lithium batteries.[1] Their tunable structures allow a variety of materials to be made and investigated.Herein,a spectrum of dipyridyl polysulfides(Py2Sn,3 ≤ n ≤ 8)was prepared in electrolyte by a one-pot synthesis method from dipyridyl disulfide(Py2S2)and elemental sulfur.It renders up to seven dipyridyl polysulfides(i.e.,Py2S3,Py2S4,Py2S5,Py2S6,Py2S7,and Py2S8)which show fully reversible electrochemical behavior in lithium batteries.[2] In the discharge,the initial lithiation occurs at 2.45 V leading to the breakage of Sα-Sβ bonds in Py2Sn and formation of lithium 2-pyridinethiolate,in which lithium is coordinated in between N and S atoms.The left sulfur species act as elemental sulfur,showing two voltage plateaus at 2.3 V and 2.1 V.The molecular dynamics simulations show the attraction between pyridyl groups and lithium polysulfides/sulfide via N···Li···S bonds,which enable good retention of soluble discharge products within electrodes and stable cycling performance.[3] In the recharge,low-order Py2Sn(e.g.,Py2S3,Py2S4,and Py2S5)remain as the charged products,but high-order Py2Sn(e.g.,Py2S6,Py2S7,and Py2S8)are diminishing.The mixture catholyte exhibits super long cycle life at 1C rate with 1200 cycles and 70.5%capacity retention.