Nan Piao

Tsinghua University | TH · Institute of Nuclear and New Energy Technology

LiNi0.5Mn1.5O4 (LNMO)/Li4Ti5O12 (LTO) spinel-spinel batteries have appealing features of high energy, high power and inherent safety. However, cycling high-voltage LNMO cathodes causes severe oxidation of conventional carbonate-based electrolytes and leads to extensive capacity decay. Herein, we report that a nonflammable all-fluorinated electrolyt...

High-energy lithium-ion batteries (LIBs) can be realized with high-capacity materials such as nickel-rich cathode, however, their reversible operation requires long-term cathode-electrolyte interfacial stability, especially for high temperature application, but how the cathode electrolyte interphases (CEIs) evolutes during operation is still a myst...

LiNi x Co y Mn z O 2 (x+y+z=1)||graphite lithium‐ion battery (LIB) chemistry promises practical applications. However, its low‐ temperature (≤ ‐20 o C) performance is poor because the increased resistance encountered by Li + transport in and across the bulk electrolytes and the electrolyte/electrode interphases induces capacity loss and battery fai...

LiNi x Co y Mn z O 2 (x+y+z=1)||graphite lithium‐ion battery (LIB) chemistry promises practical applications. However, its low‐ temperature (≤ ‐20 o C) performance is poor because the increased resistance encountered by Li + transport in and across the bulk electrolytes and the electrolyte/electrode interphases induces capacity loss and battery fai...

Currently, the demand for clean energy to replace fossil energy is increasing dramatically, which is driving the fast development of lithium batteries and other advanced battery systems with high energy density, high power density, good safety and low price. On the way from laboratory to market, the problems of different materials and battery syste...

LiFePO4, one of the most widely used cathode materials in Li -ion batteries, has many excellent properties, such as low-cost, long life and excellent safety. Unfortunately, its poor performance at low temperature hinders its use in cold regions of the world. The incorporation of carbon materials, which also have excellent electronic and ionic condu...

The lithium metal anode is considered as the ultimate choice for high-energy-density batteries. However, the organic-dominated solid electrolyte interphase (SEI) formed in carbonate electrolytes has a low interface energy against metallic Li as well as a high resistance, resulting in a low Li plating/stripping Coulombic efficiency (CE) of less than...

A NaClO4/NaOTF electrolyte was designed for aqueous Na-ion batteries (ASIBs). The solid electrolyte interphase (SEI) containing NaF–Na2O–NaOH forming on the anode extended the cathodic limiting potential of electrolyte to 1.6 V, and the hydrophobic anions extend the anodic to 4.4 V. A 1.75 V Na3V2(PO4)3∥Na3V2(PO4)3 cell achieved a high energy densi...

“Water‐in‐salt” electrolytes (WISE) have largely widen the electrochemical stability window (ESW) of aqueous electrolytes by formation of passivating solid electrolyte interphase (SEI) on anode and also absorption of hydrophobic anion‐rich double layer on cathode. However, the cathodic limiting potential of WISE is still too high for most high capa...

Lithium bis(fluorosulfonyl)amide (LiFSI)-based electrolytes not only deliver improved ionic conductivity, but also provide high thermal stability and water tolerance. However, the notorious corrosion of sulfonamide anions against aluminum (Al) current collector restricts their application. High concentration electrolytes (HCEs) have been proposed a...

Lithium (Li) metal is a promising anode for high-performance secondary lithium batteries with high energy density due to its highest theoretical specific capacity and lowest electrochemical potential among anode materials. However, the dendritic growth and detrimental reactions with electrolyte during Li plating raise safety concerns and lead to pr...

All-solid-state Li metal batteries have attracted extensive attention due to their high safety and high energy density. However, Li dendrite growth in solid-state electrolytes (SSEs) still hinders their application. Current efforts mainly aim to reduce the interfacial resistance, neglecting the intrinsic dendrite-suppression capability of SSEs. Her...

In carbonate electrolytes, the organic‐inorganic solid electrolyte interphase (SEI) formed on the lithium (Li) metal anode surface is strongly bonded to Li and experiences the same volume change as Li, thus it undergoes continuous cracking/reformation during plating/stripping cycles. Here, an inorganic‐rich SEI is designed on a Li metal surface to...

An inorganic‐rich solid electrolyte interphase (SEI) has been constructed on Li metal to promote dense Li growth with a Coulombic efficiency of 99.55 % in the carbonate electrolyte. It was synthesized on the surface of the Li‐metal anode using concentrated LiNO3 in dimethyl sulfoxide (DMSO) as an additive in the FEC‐based electrolyte, which partici...

Lithium metal batteries are recognized as the ultimate next generation batteries of high specific energy. The energy density is hopeful to increase by 2–3 times when lithium ion batteries change the graphite anode to lithium metal. Undesirable dendrite growth and low coulombic efficiency are known as the key problems of lithium metal anode, while t...

Jahn-Teller distorted Mn(III) (t2g³eg¹) ions play a key role in the performance of manganese-based layered oxides. Here we show that there is an obvious relationship between the Jahn-Teller distortion of a trivalent manganese and the electrochemistry in a pair of Na isomer, namely orthorhombic and hexagonal P2-type Na2/3Mn0.9Ti0.1O2 having the same...

Lithium metal is considered to be the "holy grail" electrode due to its high theoretical energy density and low potential. However, Li dendrite growth and high reactivity of Li metal towards the electrolyte result in a poor coulombic efficiency and raise safety concerns for lithium-metal batteries (LMBs). Herein, we attempt to integrate artificial...

The demand for high energy Na-ion batteries has promoted intensive research on high energy oxygen redox chemistry in layered transition metal oxide cathodes. However, most layered cathodes with oxygen redox might suffer from irreversible electrochemical reaction, fast capacity decay and underlying O2 release. Herein, we report that copper element w...

Development of electrolytes that simultaneously have high ionic conductivity, wide electrochemical window, and lithium dendrite suppression ability is urgently required for high‐energy lithium‐metal batteries (LMBs). Herein, an electrolyte is designed by adding a countersolvent into LiFSI/DMC (lithium bis(fluorosulfonyl)amide/dimethyl carbonate) el...

The anion effect on Li⁺ solvation structure and consequent electrochemical and physical properties was studied on the basis of LiFSI-DMC (lithium bisfluorosulfonyl imide-dimethyl carbonate)- and LiTFSI-DMC (lithium bis(trifluoromethanesulfonyl imide)-dimethyl carbonate)-based dilute electrolytes, highly concentrated electrolytes, and localized conc...

Carbonate electrolytes are commonly used in commercial non-aqueous Li-ion batteries. However, the high affinity between the solvents and the ions and high flammability of the carbonate electrolytes limits the battery operation temperature window to −20 to + 50 °C and the voltage window to 0.0 to 4.3 V. Here, we tame the affinity between solvents an...

The chromate conversion coating (CCC) is pretreated on the surface of aluminum current collector to effectively suppress aluminum corrosion in the lithium bis[(trifluoromethyl)sulfonyl] imide (LiTFSI)-based electrolytes. The harsh electrochemical tests show that the corrosion current density of CCC-Al is only about 1% of that of pristine aluminum....

The lithiation/delithiation of phosphate electrode materials in lithium ion batteries is often accompanied by an electrochemically driven phase transformation. The good understanding of phase transformation benefits for evaluation of SOC (state of charge) by OCV (open circuit voltage). A facile GITT (Galvanostatic Intermittent Titration Technique)...

The electrochemical behavior and pitting corrosion in a Cl- containing solution (0.05 mol/L H2SO4+0.05 mol/L NaCl) of the ultrafine-grained 304L stainless steel (304L SS) with average grain size of (130±30) nm prepared by equal channel angular pressing (ECAP) technique were examined using potentiodynamic polarization curves, cycle polarization curv...

The corrosion behavior of bulk ultra-fine grained (UFG) Fe-Ni-Cr alloy prepared by equal-channel angular pressing technique was investigated in 0.25 mol/L Na2SO4+0.05 mol/L H2SO4 solution by electrochemical measurements. As compared to the coarse grained (CG) counterpart, the UFG alloy exhibits an acceleration of the active dissolution and a shrunk...

The metallic matrix composite with ceramic nano-particles has a wide prospect in many applications due to its superior properties. The nanocomposite Ni-WC coating has been synthesized by using DC co-electrodeposition of Ni with WC nano-particles. Its hardness was measured by using ultra-micro hardness tester. Its corrosion and passive properties we...