SnO2 is considered to be a promising candidate as anode material for lithium ion batteries, due to its high theoretical specific capacity (1494 mAh·g−1). Nevertheless, SnO2-based anodes suffer from poor electronic conductivity and serious volume variation (300%) during lithiation/delithiation process, leading to fast capacity fading. To solve these problems, SnO2 quantum dots modified N-doped carbon spheres (SnO2 QDs@N–C) are fabricated by facile hydrolysis process of SnCl2, accompanied with the polymerization of polypyrrole (PPy), followed by a calcination method. When used as anodes for lithium ion batteries, SnO2 QDs@N–C exhibits high discharge capacity, superior rate properties as well as good cyclability. The carbon matrix completely encapsulates the SnO2 quantum dots, preventing the aggregation and volume change during cycling. Furthermore, the high N content produces abundant defects in carbon matrix. It is worth noting that SnO2 QDs@N–C shows excellent capacitive contribution properties, which may be due to the ultra-small size of SnO2 and high conductivity of the carbon matrix. SnO2 quantum dots modified N-doped carbon spheres are successfully fabricated by facile hydrolysis-high temperature calcination approach using SnCl2 and pyrrole monomer as precursors. As anodes for lithium ion batteries, the SnO2 QDs@N-C-600 exhibits superior rate capability and excellent cycling stability. This work provides an effective way to obtain electrode materials with high specific capacity and good cycling performance for energy storage

中文翻译：

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SnO2量子点通过增强赝电容修饰N掺杂碳作为锂离子电池的高性能负极

由于其理论比容量高（1494 mAh·g-1），SnO2 被认为是一种很有前途的锂离子电池负极材料。然而，基于SnO2的负极在锂化/脱锂过程中电子导电性差，体积变化严重（300%），导致容量快速衰减。为了解决这些问题，SnO2 量子点改性的 N 掺杂碳球（SnO2 QDs@N-C）是通过 SnCl2 的简单水解过程，伴随着聚吡咯（PPy）的聚合，然后通过煅烧方法制备的。当用作锂离子电池的负极时，SnO2 QDs@N-C 表现出高放电容量、优异的倍率性能以及良好的循环性能。碳基体完全封装了 SnO2 量子点，防止循环过程中聚集和体积变化。此外，高 N 含量会在碳基体中产生大量缺陷。值得注意的是，SnO2 QDs@N-C 表现出优异的电容贡献特性，这可能是由于 SnO2 的超小尺寸和碳基体的高导电性。以SnCl2和吡咯单体为前驱体，通过简单的水解-高温煅烧方法成功制备了SnO2量子点改性的N掺杂碳球。作为锂离子电池的负极，SnO2 QDs@NC-600 表现出优异的倍率性能和优异的循环稳定性。该工作为获得具有高比容量和良好循环性能的储能电极材料提供了一种有效途径。这可能是由于 SnO2 的超小尺寸和碳基体的高导电性。以SnCl2和吡咯单体为前驱体，通过简单的水解-高温煅烧方法成功制备了SnO2量子点改性的N掺杂碳球。作为锂离子电池的负极，SnO2 QDs@NC-600 表现出优异的倍率性能和优异的循环稳定性。该工作为获得具有高比容量和良好循环性能的储能电极材料提供了一种有效途径。这可能是由于 SnO2 的超小尺寸和碳基体的高导电性。以SnCl2和吡咯单体为前驱体，通过简单的水解-高温煅烧方法成功制备了SnO2量子点改性的N掺杂碳球。作为锂离子电池的负极，SnO2 QDs@NC-600 表现出优异的倍率性能和优异的循环稳定性。该工作为获得具有高比容量和良好循环性能的储能电极材料提供了一种有效途径。SnO2 QDs@NC-600 表现出优异的倍率性能和出色的循环稳定性。该工作为获得具有高比容量和良好循环性能的储能电极材料提供了一种有效途径。SnO2 QDs@NC-600 表现出优异的倍率性能和出色的循环稳定性。该工作为获得具有高比容量和良好循环性能的储能电极材料提供了一种有效途径。