最新Science：可充式镍-3D锌电池

— 前言 —

今日快解为Science上最新论文（Science, 2017, 356, 415-418），标题为：Rechargeable nickel–3D zinc batteries: An energy-dense, safer alternative to lithium-ion. 

— 图文快解 —

锂离子电池的安全性一直是人们所顾虑的一个问题，下一代高性能的电池应该比非水相电解质的锂离子电池有着更优异的安全性。在水相电解质中，海绵锌片电极在锌镍碱电池中能够循环成百上千次而不产生钝化和微米级的枝晶，在安全性上可以满足人们的要求。本文中，作者提出具有3D形状因子的锌电极能够在三个层面提升锌镍碱电池的性能：1）一次电池中有>90%的理论放电深度；2）在放电深度为40%，比能量与锂离子电池相当的情况下，>100次的高速循环；3）微混合动力汽车的启动与制动中，上万次的power-demanding duty cycles。下面对论文进行简单地介绍。

表 1

Fig. 1. Possibilities with rechargeable Ni–Zn. (A) Schematic of the effect of recharging Ni–Zn (conventional powder zinc anodes) versus Ni–3D Zn in which the anode is redesigned as a monolithic aperiodic sponge ensuring persistent 3D wiring of the metallic Zn core. Dendrites that form at powder-composite Zn anodes can reach hundreds of micrometers in length (30, 31). (B) The calculated specific energy of a fully packaged Ni–Zn cell as a function of increasing Zn depth of discharge versus a capacity-matched NiOOH electrode. The shaded areas highlight the specific energy range of common battery chemistries. For example, at ≥40% DODZn(percentage of theoretical utilization), Ni–Zn becomes competitive with Li-ion at the single-cell level.

锌很便宜，同时也有高的比电容和比能量，而制约锌基电池应用的一个主要因素是其循环性能，本文提出的3D海绵锌片能够较好地解决这个问题。

图2. 镍-3D锌电池的循环性能

Fig. 2.Cycling performance of nickel–3D zinc cells (A) Schematic design of the nickel–3D zinc coin cell used in this study. (B) Nickel–3D zinc cells tap >90% of the theoretical Zn capacity upon discharge (black circles, at 10 mA cm–2) and >95% of that discharged capacity can be recovered upon subsequent recharge (red squares, at 10 mA cm–2) with a half-cycle voltage hysteresis of <300 mV. (C and D) The voltage-time curves for cells discharged at 25 mA cm–2 to 40% DODZnand recharged at either (C) 5 mA cm–2 or (D) 10 mA cm–2. The constant voltage at 1.93 V indicates the potentiostatic region of the charge profile.

Fig. 3 Postcycling microstructural analysis of 3D Zn sponges. Scanning electron micrographic analysis of (A to C) precycled and (D to I) postcycled Zn sponges after >100 cycles, verifying that minimal shape change occurs and no dendrites are formed when the Ni–3D Zn cell is discharged at 25 mA cm–2 to 40% DODZn and recharged at either [(D) to (F)] 5 mA cm–2 or [(G) to (I)] 10 mA cm–2.

Fig. 4 Long-term performance of Ni–3D Zn single cell as cycled under start-stop conditions. (A) The current-time duty cycle modeled from a BMW AGM start-stop drive cycle (28) scaled to our 1-cm2 Ni–3D Zn coin cells. (B) The measured current-time curves for Ni–3D Zn coin cells at early (solid line, 4000 cycles) and late (dashed line, 54,000 cycles) points in the 4.5-month-long, nonstop cycling. (C) Micrographic analysis of a postcycled Zn sponge after ~54,000 cycles, which verifies that minimal shape change occurs and no dendrites are formed.

由于小编学识有限，在解读过程中难免有很多不科学之处，请大家批评指正，感兴趣的朋友请移步阅读原文，谢谢！

鸟语虫声总是传心之诀，花英草色无非见道之文！

随手点点下方广告，无需下载即可帮研之成理创收哦。感谢！