NiCoAl layered double hydroxide nanosheets (NiCoAl-LDHNs) were prepared by a one-step solvothermal method. The shape and size of the obtained nanosheets are optimized by adjusting the solvothermal time and the molar concentration ratio of Ni²⁺/Co²⁺ to obtain the electrode material with the best performance. When the solvothermal time is 9 h and the molar concentration ratio of Ni²⁺/Co²⁺ is 1:1, NiCoAl-LDHNs has the best morphology and electrochemical performance. When assembled into a supercapacitor, NiCoAl-LDHN-9 has a high specific capacitance of 1228.5 F g^-1 at 1 A g^-1. As the current density is increased to 20 A g^-1, the specific capacitance is 1001.8 F g^-1, which still has a high capacitance retention of 81.6%. When NiCoAl-LDHN-9 was assembled into an asymmetric supercapacitor, NiCoAl-LDHN-9//AC has a specific capacitance of 102.1 F g^-1 at 0.5 A g^-1. The asymmetric supercapacitor devices also show excellent electrochemical performance in terms of energy density (35.9Wh kg^-1 at 225.8 W kg^-1), power density (4.8 kW kg^-1 at 22.2 Wh kg^-1) and cycle life (capacitance retention rate after 10,000 cycles is 87.1%). Those results indicate that NiCoAl-LDHN have the potential to be promising electrode materials for high performance supercapacitors.

通过一步溶剂热法制备了NiCoAl层状双氢氧化物纳米片（NiCoAl-LDHNs）。通过调节溶剂热时间和Ni ²⁺ / Co ²⁺的摩尔浓度比来优化所获得的纳米片的形状和尺寸，以获得具有最佳性能的电极材料。当溶剂热时间为9 h，Ni ²⁺ / Co ²⁺的摩尔浓度比为1：1时，NiCoAl-LDHNs具有最佳的形貌和电化学性能。当组装成超级电容器时，NiCoAl-LDHN-9在1 A g ^-1时具有1228.5 F g ^-1的高比电容。随着电流密度增加到20 A g ^-1，比电容为1001.8 F g ^-1，仍然具有81.6％的高电容保持率。当NiCoAl-LDHN-9组装成非对称超电容器，NiCoAl-LDHN-9 // AC具有102.1 F G的特定电容^-1 0.5 A G ^-1。不对称超级电容器装置还显示在能量密度方面优异的电化学性能（35.9Wh千克^-1在225.8千克w ^ ^-1），功率密度（4.8千瓦千克^-1在22.2瓦千克^-1）和循环寿命（电容量保持率10,000次循环后为87.1％）。这些结果表明，NiCoAl-LDHN有潜力成为用于高性能超级电容器的有希望的电极材料。