| 基于链状SemSn(2≤m+n≤4)小分子的硒硫碳复合正极材料的制备及其电化学性能 |
| Preparation and Electrochemical Performance of Selenium/Sulfur/Carbon Composite Cathode Materials Based on Chain-like Small SemSn (2≤m+n≤4) Molecules |
| 作者 | 单位 | E-mail | | 严奉乾 | 南昌大学光伏研究院, 南昌 330031 | | | 景鑫国 | 南昌大学光伏研究院, 南昌 330031 | | | 范廷云 | 南昌大学光伏研究院, 南昌 330031 | | | 朱禾生 | 南昌大学光伏研究院, 南昌 330031 | | | 刘闪 | 南昌大学光伏研究院, 南昌 330031 | | | 刘晨旭 | 南昌大学光伏研究院, 南昌 330031 | | | 吴熙 | 南昌大学光伏研究院, 南昌 330031 | | | 丁国彧 | 南昌大学光伏研究院, 南昌 330031 | | | 江伟伟 | 南昌大学光伏研究院, 南昌 330031 | | | 唐昌新 | 南昌大学光伏研究院, 南昌 330031 | tcx@ncu.edu.cn | | 孙福根 | 南昌大学光伏研究院, 南昌 330031 | sunfugen@ncu.edu.cn |
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| 摘要: 将Se固溶复合到链状小硫分子S2~4中，利用超微孔碳(UMC)的空间限域效应，在UMC中成功构建了链状SemSn(2≤m+n≤4)小分子，并用作锂硫(Li-S)电池正极材料。与链状S2~4小分子相比，改性后的SemSn(2≤m+n≤4)小分子电导率更高，锂化能更低，放电锂化过程更容易。所制得的UMC/SemSn(2≤m+n≤4)复合正极材料的放电过程为一步固相转化反应，从而有效抑制了活性物质的穿梭流失。与UMC/S2~4复合正极材料相比，UMC/SemSn(2≤m+n≤4)复合正极材料的电荷传递阻抗更小，放电比容量更高。因此，UMC/SemSn-40(2≤m+n≤4，wSeS2∶wUMC=4∶6)复合正极材料在0.1C时循环100次后，比容量依然保持有844 mAh·g-1；在0.5C下长时间循环500次时，每次循环容量损失仅约为0.07%，表现出优异的循环稳定性。 |
| 关键词: 锂硫电池 硫正极 硒硫固溶体 小硫分子 硒硫碳复合物 |
| 基金项目: 国家自然科学基金(No.51962022)、江西省大学生创新创业训练计划(No.202010403014)和江西省研究生创新专项资金(No.YC2020-S069)资助。 |
| Abstract: Chain-like small SemSn (2≤m+n≤4) molecules were successfully constructed in the ultra-microporous carbons (UMC) by the incorporation of Se into the chain-like small S2-4 molecules and space-confining of UMC, and then used as cathode materials for lithium-sulfur (Li-S) batteries. Compared with the chain-like small S2-4 molecules, the chain-like small SemSn (2≤m+n≤4) molecules have higher electronic conductivity, lower lithiation energy, and higher electrochemical activity. Moreover, the obtained UMC/SemSn (2≤m+n≤4) composites exhibited a one-step solid conversion behavior during the discharge process, which could effectively prohibit the shuttle and loss of active materials in Li-S batteries. Compared with UMC/S2-4 composites, UMC/SemSn (2≤m+n≤4) composites deliver lower charge-transfer resistance and higher discharge specific capacity. Therefore, UMC/SemSn-40 (2≤m+n≤4, wSeS2∶wUMC= 4∶6) composites maintained a high reversible specific capacity of 844 mAh·g-1 at the current rate of 0.1C after 100 cycles and long-term cycling stability over 500 cycles with the capacity decay rate of about 0.07% per cycle at the current rate of 0.5C. |
| Keywords: lithium-sulfur battery sulfur cathode selenium-sulfur solid solution small sulfur molecule selenium/sulfur/carbon composites |
| 投稿时间：2021-11-01 修订日期：2022-02-25 |
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| 严奉乾,景鑫国,范廷云,朱禾生,刘闪,刘晨旭,吴熙,丁国彧,江伟伟,唐昌新,孙福根.基于链状SemSn(2≤m+n≤4)小分子的硒硫碳复合正极材料的制备及其电化学性能[J].无机化学学报,2022,38(4):645-653. |
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