Zincronization-induced surface modification of CoMn phosphate for improved electrochemical performance in battery-supercapacitor hybrid systems

Transition metal phosphates have emerged as a promising candidate for electrochemical energy storage devices due to their high theoretical capacity and environmental sustainability. Yet the experimentally obtained results lack for behind the commutated one primely caused by incomplete ignition of active material due to polarization and surface passivation. This research article explores the effects of zinc (Zn) addition on the electrochemical performance of CoMn phosphate, aiming to unlock new avenues for improved energy storage solutions. The nanoflakes of CoMn Phosphate were synthesized via a sonochemical process. Afterward, zinc was introduced to this bimetallic phosphate configuration that has a significantly tuned surface morphology. With reformed nanoflakes structures the zincronized CoMn Phosphate has profited a specific capacity of 943.68C/g at 3 mV/s and 859.08C/g while operating on 1.2 A/g (2.53 times more than CoMn Phosphate). The subjection of this zincronized CoMn Phosphate into a battery-supercapacitor hybrid configuration as positive electrode material has delivered a specific capacity of 490.36C/g with exceptional specific energy and power of 115.78 Wh/kg, and 1190 W/kg respectively at cost of 1.4 A/g. Notably the device shows an extraordinary perseverance via delivering 84.39 Wh/kg (72.89 % of maximum) and an outstanding power density of 4250 W/kg at 5.0 A/g. Additionally, the hybrid device has demonstrated 96.92 % capacity retention with similar conductive characteristics after 4000 cycles. Simulation of electrochemical outcomes has revealed a capacitive contribution of 35.51 % at 5 mV/s which increases to 71.12 % at 100 mV/s. The study provides a new pathway for the modification of transition metal phosphate with improved electrochemical performance, addressing key challenges that have hindered its widespread applications.