Although solid-state lithium (Li)-metal batteries promise both high energy density and safety, existing solid ion conductors fail to satisfy the rigorous requirements of battery operations. Inorganic ion conductors allow fast ion transport, but their rigid and brittle nature prevents good interfacial contact with electrodes. Conversely, polymer ion conductors that are Li-metal-stable usually provide better interfacial compatibility and mechanical tolerance, but typically suffer from inferior ionic conductivity owing to the coupling of the ion transport with the motion of the polymer chains^1,2,3. Here we report a general strategy for achieving high-performance solid polymer ion conductors by engineering of molecular channels. Through the coordination of copper ions (Cu²⁺) with one-dimensional cellulose nanofibrils, we show that the opening of molecular channels within the normally ion-insulating cellulose enables rapid transport of Li⁺ ions along the polymer chains. In addition to high Li⁺ conductivity (1.5 × 10⁻³ siemens per centimetre at room temperature along the molecular chain direction), the Cu²⁺-coordinated cellulose ion conductor also exhibits a high transference number (0.78, compared with 0.2–0.5 in other polymers²) and a wide window of electrochemical stability (0–4.5 volts) that can accommodate both the Li-metal anode and high-voltage cathodes. This one-dimensional ion conductor also allows ion percolation in thick LiFePO₄ solid-state cathodes for application in batteries with a high energy density. Furthermore, we have verified the universality of this molecular-channel engineering approach with other polymers and cations, achieving similarly high conductivities, with implications that could go beyond safe, high-performance solid-state batteries.

尽管固态锂 (Li) 金属电池承诺高能量密度和安全性，但现有的固态离子导体无法满足电池操作的严格要求。无机离子导体允许快速离子传输，但它们的刚性和脆性特性阻碍了与电极的良好界面接触。^{相反，锂金属稳定的聚合物离子导体通常提供更好的界面相容性和机械耐受性，但由于离子传输与聚合物链1,2,3}的运动的耦合，通常会遭受较差的离子电导率。在这里，我们报告了通过分子通道工程实现高性能固体聚合物离子导体的一般策略。通过铜离子（Cu ²⁺) 使用一维纤维素纳米纤丝，我们表明在正常离子绝缘的纤维素中打开分子通道可以使锂离子沿聚合物链快速^传输。除了高 Li ⁺电导率（室温下沿分子链方向为1.5 × 10 ^{-3西门子/厘米）外，Cu 2+}配位的纤维素离子导体还表现出高迁移数（0.78，而在室温下为 0.2-0.5 in其他聚合物² ) 和宽广的电化学稳定性窗口（0-4.5 伏），可同时容纳锂金属负极和高压正极。这种一维离子导体还允许离子在厚 LiFePO _4中渗透用于高能量密度电池的固态阴极。此外，我们已经验证了这种分子通道工程方法与其他聚合物和阳离子的普遍性，实现了类似的高电导率，其意义可能超越安全、高性能的固态电池。