Nickel-manganese phosphate/graphene foam (GF) composite was successfully synthesized through a simple and direct hydrothermal approach, serving as highly efficient electrodes for hybrid device. Ni and Mn are both redox metals owing to their multiple oxidation states however, Ni-based materials possess higher capacity due to its strong faradic mechanism while Mn-based materials offer pseducapacitive nature and GF for its ability to improve the surface area as well as the electrical conductivity of the composite. Consequently, the prepared NiMn(PO₄)₂/GF composite achieved a maximum specific capacity of 97 mAh g ^− 1 at 0.5 A g ^− 1 in a 3-electrode configuration setup compared to 63 mAh g ^− 1 for the pristine material. Thus, NiMn(PO₄)₂/GF considered as a positive electrode in a hybrid device with carbon derived from Capsicum (bell pepper) seeds “peppered”-activated carbon (ppAC) as a negative electrode. The hybrid device reported a maximum energy density of 35.42 Wh kg⁻¹ corresponding to a power density of 538 W kg⁻¹ at 0.5 A g ^− 1. The NiMn(PO₄)₂/GF//ppAC hybrid device also showed high stability of 97.8% capacity retention over 10,000 cycles at 6 A g ^− 1, ∼93% float time efficiency after 120 h and could still preserve ∼1.17 V against its initial cell potential of 1.5 V after 60 h of self-discharge. The outstanding performance of NiMn(PO₄)₂/GF material in a half and full cell makes it a good candidate for supercapacitor application.

镍锰磷酸盐/石墨烯泡沫（GF）复合材料通过简单直接的水热方法成功合成，可作为混合设备的高效电极。Ni和Mn均由于其多种氧化态而均为氧化还原金属，但是，Ni基材料由于其强大的法拉第机理而具有更高的容量，而Mn基材料提供了可延性的性质，而GF具有改善表面积和抗氧化性的能力。复合材料的电导率。因此，所制备的NiMn（PO ₄）₂ / GF复合达到97毫安时的最大比容量克 ^{-  1}在0.5 A克 ^{-  1}在一个3电极配置设置相比63毫安 原始材料的g ^{−  1}。因此，NiMn（PO ₄）₂ / GF被认为是混合设备中的正极，而辣椒素（甜椒）衍生的碳种子将“胡椒粉”活性炭（ppAC）用作负极。该混合设备报告的35.42公斤瓦的最大能量密度^-1对应于538千克w ^的功率密度^-1在0.5 A克 ^{-  1}。NiMn（PO ₄）₂ / GF // ppAC混合器件在6 A g  ^{−  1的}10,000个循环中也显示出97.8％的容量保持率的高稳定性，在120小时后浮空时间效率约为93％，自放电60小时后仍能保持约1.17 V的初始电池电位1.5V。NiMn（PO ₄）₂ / GF材料在半电池和全电池中的出色性能使其成为超级电容器应用的良好候选者。