Metal pyrophosphate-based materials for supercapattery have recently attracted significant research interest due to their high energy density, structural stability, and cyclability. Despite this, the low electric conductivity of such compounds severely limits the rate efficiency of supercapattery. To address this challenge, self-assembly of strontium pyrophosphate (SrPO) on 2D reduced graphene oxide (rGO) was produced (SrPO@2D rGO) with varying urea and rGO proportions employing a two-stage procedure: (i) layer-by-layer (LBL) deposition of rGO nanosheets, followed by (ii) a hydrothermal method to produce strontium pyrophosphate (SP) microflakes. The effective integration of conductive rGO with SrPO flakes has been verified by structural and morphological investigation, which indicates that rGO nanosheets offer a large number of active sites, high electrical conductivity, and a wide surface area. However, when compared to the other electrodes, the optimized SP/rGO-3 hybrid electrode possesses battery-like properties, with an outstanding specific capacity of 205 mAh/g (738C/g) in 1 M KOH at a current density of 2 A/g and maintains 99 % durability after 10000 cycles. These outcomes imply a synergistically enhanced surface redox charge storage mechanism through the inclusion of rGO (optimal) and the influence of SP nano/microarchitecture, resulting in an extended cycle lifespan and remarkable electrochemical characteristics. Furthermore, a hybrid solid-state (HSS) supercapattery developed by employing SP/rGO-3 as the cathode and rGO as the anode (SP/rGO-3//rGO) achieved a maximum specific (areal) capacity of 189C/g (52 mAh/g, 133 mF cm), (areal) energy density of 42.04 Wh/kg (47.3 mWh cm), and a power density of 2755.6 W/kg (3.1 mW cm). In addition, the HSS device demonstrates remarkable long-term cyclability, retaining 96 % capacity after 10000 cycles. The present research suggests that SrPO@2D rGO composites have extraordinary electrochemical properties, highlighting their potential as nano/micro-structured electrodes for future energy storage devices.

中文翻译：

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Sr2P2O7@2D rGO纳米/微米结构的自组装用于高度耐用和可弯曲的固态超级电容器


用于超级电池的金属焦磷酸盐材料由于其高能量密度、结构稳定性和可循环性，最近引起了人们的广泛研究兴趣。尽管如此，此类化合物的低电导率严重限制了超级电容器的倍率效率。为了应对这一挑战，采用两阶段程序，使用不同的尿素和 rGO 比例，在二维还原氧化石墨烯 (rGO) 上自组装焦磷酸锶 (SrPO) (SrPO@2D rGO)：(i) 逐层制备rGO 纳米片的层 (LBL) 沉积，然后 (ii) 水热法生产焦磷酸锶 (SP) 微米薄片。通过结构和形态研究验证了导电rGO与SrPO薄片的有效结合，这表明rGO纳米片具有大量的活性位点、高电导率和宽的表面积。然而，与其他电极相比，优化的 SP/rGO-3 混合电极具有类似电池的特性，在 1 M KOH 中、电流密度为 2 A 时具有 205 mAh/g (738C/g) 的出色比容量/g，10000 次循环后仍保持 99% 的耐用性。这些结果意味着通过包含 rGO（最佳）和 SP 纳米/微米结构的影响，协同增强表面氧化还原电荷存储机制，从而延长循环寿命和显着的电化学特性。此外，采用SP/rGO-3作为阴极和rGO作为阳极（SP/rGO-3//rGO）开发的混合固态（HSS）超级电容器实现了189C/g的最大比（面积）容量（ 52 mAh/g，133 mF cm），（面积）能量密度为 42.04 Wh/kg (47.3 mWh cm)，功率密度为 2755.6 W/kg (3.1 mW cm)。 此外，HSS 器件表现出卓越的长期循环性能，在 10000 次循环后仍保留 96% 的容量。目前的研究表明，SrPO@2D rGO 复合材料具有非凡的电化学性能，突出了它们作为未来储能设备的纳米/微米结构电极的潜力。