Freestanding electrodes for lithium ion batteries are considered as a promising option to increase the total gravimetric energy density of the cells due to a decreased weight of electrochemically inactive materials. We report a simple procedure for the fabrication of freestanding LiFe_0.2Mn_0.8PO₄ (LFMP)/rGO electrodes with a very high loading of active material of 83 wt%, high total loading of up to 8 mg cm⁻², high energy density, excellent cycling stability and at the same time very fast charging rate, with a total performance significantly exceeding the values reported in the literature. The keys to the improved electrode performance are optimization of LFMP nanoparticles via nanoscaling and doping; the use of graphene oxide (GO) with its high concentration of surface functional groups favoring the adhesion of high amounts of LFMP nanoparticles, and freeze-casting of the GO-based nanocomposites to prevent the morphology collapse and provide a unique fluffy open microstructure of the freestanding electrodes. The rate and the cycling performance of the obtained freestanding electrodes are superior compared to their Al-foil coated equivalents, especially when calculated for the entire weight of the electrode, due to the extremely reduced content of electrochemically inactive material (17 wt% of electrochemically inactive material in case of the freestanding compared to 90 wt% for the Al-foil based electrode), resulting in 120 mAh g⁻¹_electrode in contrast to 10 mAh g⁻¹_electrode at 0.2 C. The electrochemical performance of the freestanding LFMP/rGO electrodes is also considerably better than the values reported in literature for freestanding LFMP and LMP composites, and can even keep up with those of LFP-based analogues. The freestanding LFMP/rGO reported in this work is additionally attractive due to its high gravimetric energy density (604 Wh kg⁻¹_LFMP at 0.2C). The obtained results demonstrate the advantage of freestanding LiFe_0.2Mn_0.8PO₄/rGO electrodes and their great potential for applications in lithium ion batteries.

由于减少了电化学惰性材料的重量，用于锂离子电池的独立式电极被认为是增加电池总重量能量密度的有前途的选择。我们报告了一种用于制备独立式LiFe _0.2 Mn _0.8 PO ₄（LFMP）/ rGO电极的简单程序，该电极具有83 wt％的非常高的活性材料负载量，高达8 mg cm ^-2的高总负载量高能量密度，出色的循环稳定性以及非常快的充电速度，其总体性能大大超过了文献报道的值。改善电极性能的关键是通过纳米缩放和掺杂来优化LFMP纳米颗粒。使用具有高浓度表面官能团的氧化石墨烯（GO）促进大量LFMP纳米颗粒的粘附，并冻结浇铸GO基纳米复合材料以防止形貌崩溃并提供独特的蓬松开放微结构独立式电极。与独立式铝箔涂层相比，获得的独立式电极的速率和循环性能优越，尤其是按电极的总重量计算时，^-1_电极在0.2 C时为10 mAh g ^-1_电极。独立式LFMP / rGO电极的电化学性能也明显优于文献中报道的独立LFMP和LMP复合材料的值，甚至可以跟上基于LFP的类似物。这项工作中报道的独立式LFMP / rGO具有较高的重量能量密度（0.2C时为604 Wh kg ^-1 _LFMP），因此更具吸引力。获得的结果证明了独立式LiFe _0.2 Mn _0.8 PO ₄ / rGO电极的优势及其在锂离子电池中的巨大应用潜力。