Introducing diffusion-controlled battery materials to supercapacitors, can significantly enhance the energy density of supercapacitors, which however encounter depressed power density due to the intrinsic sluggish charge storage kinetics of battery materials. This problem can be efficiently solved by modifying the microstructure, and enable capacitive controlled charge storage mechanism in the battery materials. In this work, a novel interface-rich core-shell structure with (NH₄)(Ni,Co)PO₄·0.67 H₂O nanosheets @ single crystal microplatelets (NH₄)(Ni,Co)PO₄·0.67 H₂O (NCoNiP@NCoNiP) is constructed via a facile two-step hydrothermal method, taking advantage of etching induced Kirkendall effect and Ostwald ripening. This unique structure can enable the extrinsic pseudocapacitance by providing extra charges (e.g. holes, electrons or voids) on the interfaces, and realize synergy and fast charge storage. Specifically, a maximum specific capacity of 190.3 mAh g⁻¹ and ultrahigh rate performance with capacity retention of 96.1% from 1 to 10 A g⁻¹ in a three-electrode test. The kinetic analysis indicates that the electrochemical response of the hybrid battery-supercapacitor storage devices shows obvious characteristic of supercapacitor especially at high scanning rates. Simultaneously, the hybrid battery-capacitor devices based on NCoNiP@NCoNiP exhibits a high energy density of 44.5 Wh kg⁻¹ at a power density of 150 W kg⁻¹, which maintains 30 Wh kg⁻¹ at high power density of 7.4 kW kg⁻¹ with capacitance retention 77.5% after 7000 cycles. This work provides a novel strategy for the application of battery materials in high power devices, by enabling the capacitive charge storage mechanism of battery materials through nanostructure engineering.

将扩散控制的电池材料引入超级电容器可以显着提高超级电容器的能量密度，但是由于电池材料固有的缓慢的电荷存储动力学，超级电容器的能量密度会降低。该问题可以通过改变微观结构来有效地解决，并且可以在电池材料中实现电容控制的电荷存储机制。在这项工作中，具有（NH ₄）（Ni，Co）PO ₄ ·0.67 H ₂ O纳米片@单晶微片（NH ₄）（Ni，Co）PO ₄ ·0.67 H ₂的新型富界面的核-壳结构O（NCoNiP @ NCoNiP）通过一种容易的两步水热法构造，利用了蚀刻引起的柯肯达尔效应和奥斯特瓦尔德熟化的优势。这种独特的结构可以通过在界面上提供额外的电荷（例如空穴，电子或空隙）来实现外部伪电容，并实现协同作用和快速的电荷存储。具体而言，最大比容量为190.3 mAh g ^-1，超高倍率性能从1至10 A g ^-1保持96.1％的容量在三电极测试中。动力学分析表明，混合动力电池-超级电容器存储装置的电化学响应表现出明显的超级电容器特性，尤其是在高扫描速率下。同时，基于NCoNiP @ NCoNiP的混合动力电池电容器设备在150 W kg ^-1的功率密度下表现出44.5 Wh kg ^-1的高能量密度，在7.4 kW kg的高功率密度下保持30 Wh kg ^-1的能量密度^-1 7000次循环后具有电容保留77.5％。通过通过纳米结构工程实现电池材料的电容性电荷存储机制，这项工作为电池材料在高功率设备中的应用提供了一种新颖的策略。