CIC Energigune, Albert Einstein 48, 01510 Miñano, Álava, Spain.
Key Laboratory for Large-Format Battery Materials and System-Ministry of Education, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
Chem Soc Rev. 2017 Feb 6;46(3):797-815. doi: 10.1039/c6cs00491a.
Electrochemical energy storage is one of the main societal challenges to humankind in this century. The performances of classical Li-ion batteries (LIBs) with non-aqueous liquid electrolytes have made great advances in the past two decades, but the intrinsic instability of liquid electrolytes results in safety issues, and the energy density of the state-of-the-art LIBs cannot satisfy the practical requirement. Therefore, rechargeable lithium metal batteries (LMBs) have been intensively investigated considering the high theoretical capacity of lithium metal and its low negative potential. However, the progress in the field of non-aqueous liquid electrolytes for LMBs has been sluggish, with several seemingly insurmountable barriers, including dendritic Li growth and rapid capacity fading. Solid polymer electrolytes (SPEs) offer a perfect solution to these safety concerns and to the enhancement of energy density. Traditional SPEs are dual-ion conductors, in which both cations and anions are mobile and will cause a concentration polarization thus leading to poor performances of both LIBs and LMBs. Single lithium-ion (Li-ion) conducting solid polymer electrolytes (SLIC-SPEs), which have anions covalently bonded to the polymer, inorganic backbone, or immobilized by anion acceptors, are generally accepted to have advantages over conventional dual-ion conducting SPEs for application in LMBs. A high Li-ion transference number (LTN), the absence of the detrimental effect of anion polarization, and the low rate of Li dendrite growth are examples of benefits of SLIC-SPEs. To date, many types of SLIC-SPEs have been reported, including those based on organic polymers, organic-inorganic hybrid polymers and anion acceptors. In this review, a brief overview of synthetic strategies on how to realize SLIC-SPEs is given. The fundamental physical and electrochemical properties of SLIC-SPEs prepared by different methods are discussed in detail. In particular, special attention is paid to the SLIC-SPEs with high ionic conductivity and high LTN. Finally, perspectives on the main challenges and focus on the future research are also presented.
电化学储能是本世纪人类面临的主要社会挑战之一。在过去的二十年中，使用非水电解质的经典锂离子电池 (LIB) 的性能取得了重大进展，但液体电解质的固有不稳定性导致了安全问题，而最先进的 LIB 的能量密度无法满足实际需求。因此，考虑到金属锂的高理论容量及其低负电势，可充电锂金属电池 (LMB) 得到了广泛的研究。然而，LMB 用非水电解液领域的进展一直很缓慢，存在几个似乎无法克服的障碍，包括枝晶锂的生长和快速容量衰减。固体聚合物电解质 (SPE) 为解决这些安全问题和提高能量密度提供了完美的解决方案。传统的 SPE 是双离子导体，其中阳离子和阴离子都是可移动的，这会导致浓度极化，从而导致 LIB 和 LMB 的性能都很差。阴离子共价键合到聚合物、无机主链或被阴离子受体固定的单锂离子 (Li-ion) 导电固体聚合物电解质 (SLIC-SPE) 通常被认为优于传统的双离子导电 SPE，适用于 LMB。高锂离子迁移数 (LTN)、不存在阴离子极化的有害影响以及较低的锂枝晶生长速率是 SLIC-SPE 的优点。迄今为止，已经报道了许多类型的 SLIC-SPE，包括基于有机聚合物、有机-无机杂化聚合物和阴离子受体的 SLIC-SPE。在这篇综述中，简要概述了实现 SLIC-SPE 的合成策略。详细讨论了不同方法制备的 SLIC-SPE 的基本物理和电化学性质。特别是，特别关注具有高离子电导率和高 LTN 的 SLIC-SPE。最后，还对主要挑战和未来研究重点提出了展望。
