Preparation and Properties of P-Bi2Te3/MXene Superstructure-based Anode for Potassium-Ion Battery
With increasing global energy demand and stricter environmental protection requirements,energy storage technology has become a research hotspot in the global energy field.New types of energy storage devices continue to emerge owing to the continuous development of cost-effective energy storage technology.Among them,potassium-ion batteries have received widespread attention as a new type of alkali metal ion battery because of their high capacity and low cost and are considered one of the future development directions.However,the research on potassium-ion batteries is still in its infancy,with many challenges to overcome regarding practical applications.A key factor affecting the performance of potassium-ion batteries is the anode material,as it not only affects the manufacturing costs but also directly affects the power density and energy density of the battery.Traditional anode materials for lithium-ion batteries cannot meet the requirements of potassium-ion batteries.Therefore,developing high-performance anode materials suitable for potassium-ion batteries is an important research direction at present.The charge and discharge rate and cycling life of potassium-ion batteries also need further improvements.Currently,the low-rate performance,short cycle life,and unsatisfactory practical capacities limit their practical application and commercialization.However,the future of potassium-ion batteries remains promising.Upon resolving the aforementioned issues,potassium-ion batteries will have diverse application prospects,such as electric vehicles,energy storage stations,and smart grids,providing important support for solving energy problems.Therefore,the research and development of potassium-ion batteries are an important direction in the global energy field.Current research efforts are primarily focused on exploring novel anode materials with exceptional ratability and cyclability.In this regard,we synthesized a new type of anode material based on bismuth telluride(Bi2Te3)and experimentally studied its applicability in potassium-ion batteries.The performance of Bi2Te3 anode for potassium-ion batteries has been limited by its structural instability and slow electrochemical reaction kinetics.In this study,rod-like Bi2Te3 was grown on accordion-like MXene,followed by P-doping to obtain a high-performance P-Bi2Te3/MXene superstructure.This novel anode had abundant Te vacancies and good self-auto adjustable function,providing excellent cycling stability(323.1 mAh·g-1 after 200 cycles at 0.2 A·g-1)and outstanding rate capability(67.1 mAh·g-1 at 20 A·g-1).Kinetic analysis and ex situ characterization indicate that the superstructure exhibits superior pseudocapacitive properties,high electrical conductivity,favorable diffusion capability,and reversible insertion and conversion reaction mechanism.
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