Beijing Key Laboratory of Energy Conversion and Storage Materials, College of Chemistry, Beijing Normal University, Beijing 100875, China; Qian Xuesen Laboratory of Space Technology, China Academy of Space Technology (CAST), Beijing 100094, China.
Interdisciplinary Research Center of Low-carbon Technology and Equipment, College of Mechanical and Vehicle Engineering, Hunan University, Changsha 410082, China.
J Colloid Interface Sci. 2023 Sep 15;646:538-546. doi: 10.1016/j.jcis.2023.05.038. Epub 2023 May 9.
Silicon (Si) is considered as one of the most promising candidates for next-generation lithium-ion battery (LIB) anode due to its high theoretical capacity. However, the drastic volume change of Si anodes during lithiation/delithiation processes leads to rapid capacity fade. Herein, a three-dimensional Si anode with multiple protection strategy is proposed, including citric acid-modification of Si particles (CA@Si), GaInSn ternary liquid metal (LM) addition, and porous copper foam (CF) based electrode. The CA modified supports strong adhesive attraction of Si particles with binder and LM penetration maintains good electrical contact of the composite. The CF substrate constructs a stable hierarchical conductive framework, which could accommodate the volume expansion to retain integrity of the electrode during cycling. As a result, the obtained Si composite anode (CF-LM-CA@Si) demonstrates a discharge capacity of 3.14 mAh cm after 100 cycles at 0.4 A g, corresponding to 76.1% capacity retention rate based on the initial discharge capacity and delivers comparable performance in full cells. The present study provides an applicable prototype of high-energy density electrodes for LIBs.
硅（Si）由于其高理论容量，被认为是下一代锂离子电池（LIB）阳极最有前途的候选材料之一。然而，Si 阳极在锂化/脱锂过程中的剧烈体积变化导致其容量迅速衰减。在此，提出了一种具有多种保护策略的三维 Si 阳极，包括 Si 颗粒的柠檬酸修饰（CA@Si）、镓铟锡三元液态金属（LM）的添加以及基于多孔铜泡沫（CF）的电极。CA 修饰的支撑物具有与粘结剂的 Si 颗粒的强附着力，LM 渗透保持了复合材料的良好电接触。CF 基底构建了一个稳定的分层导电框架，在循环过程中可以容纳体积膨胀，以保持电极的完整性。因此，所得到的 Si 复合阳极（CF-LM-CA@Si）在 0.4 A g 下循环 100 次后表现出 3.14 mAh cm的放电容量，基于初始放电容量的容量保持率为 76.1%，并在全电池中表现出相当的性能。本研究为 LIB 提供了一种适用于高能密度电极的原型。
