Currently ether solvents have been regarded as the most compatible organic solvents with lithium metal in electrolytes of lithium batteries.However,ether solvents are unstable under high voltage(＞4.0 V),and prone to side reactions with nickel-rich high-voltage cathode materials.In this work,a novel dual-solvent electrolyte in ethylene glycol dimethyl ether(DME)and butyronitrile(BN)mixed solvent was designed and fabricated for Li/LiNi0.5Mn0.3Co0.2O2-based lithium metal batteries.When charged to high voltage 4.3 V,the battery cycled in this optimal electrolyte can maintain the capacity at 133.7 mAh g-1 with a retention of 88.84％after 150 cycles at 0.2 C and-10℃.During long-term cycling,the battery also exhi-bits excellent cycling performance with capacity maintained at about 112.0 mAh g-1 after 500 cycles at 1 C and-10℃.BN has strong oxidation resistance and high conductivity,which can inhibit the decompo-sition of ether solvents under high voltage and improve the low temperature performance of battery effectively.Additionally,the cyano(-C≡N)group in BN molecular has a strong coordination ability with the high-valent metal ions and can mask the active ions on the cathode,correspondingly reducing the corrosion of cathode material by the electrolyte.Moreover,cyano group can participate in the hydrolysis to remove trace amounts of water and acidic by-products such as HF in the electrolyte.Therefore,the boosting effect of butyronitrile for ether solvents can provide a promising strategy for enhancing the per-formance of high voltage lithium metal batteries for practical industrialization.

Jingrong Ning;Kaijia Duan;Kai Wang;Jianwen Liu;Shiquan Wang;Jiujun Zhang

College of Chemistry and Chemical Engineering&Collaborative Innovation Center for Advanced Organic Chemical Materials Co-constructed by the Province and Ministry&Ministry of Educational Key Laboratory for the Synthesis and Application of Organic Functional Molecules,Hubei University,Wuhan 30062,Hubei,China;Institute for Sustainable Energy/College of Science,Shanghai University,Shanghai 200444,China

能源化学

[1]Jingrong Ning;Kaijia Duan;Kai Wang;Jianwen Liu;Shiquan Wang;Jiujun Zhang-.Boosting practical high voltage lithium metal batteries by butyronitrile in ether electrolytes via coordination,hydrolysis of C≡N and relatively mild concentration strategy)[J].能源化学,2022(04):290-299

butyronitrile

Boosting,practical,high,voltage,lithium,metal,batteries,by,ether,electrolytes,via,coordination,hydrolysis,relatively,mild,concentration,strategy,Currently,solvents,have,been,regarded,most,compatible,organic,However,are,unstable,under,prone,side,reactions,nickel,rich,cathode,materials,In,this,work,novel,dual,ethylene,glycol,dimethyl,DME,BN,mixed,was,designed,fabricated,LiNi0,5Mn0,3Co0,2O2,When,charged,battery,cycled,optimal,can,capacity,mAh,retention,after,cycles,During,long,term,cycling,also,exhi,bits,excellent,performance,maintained,about,has,strong,oxidation,resistance,conductivity,which,inhibit,decompo,sition,improve,low,temperature,effectively,Additionally,cyano,group,molecular,ability,valent,mask,active,correspondingly,reducing,corrosion,Moreover,participate,remove,trace,amounts,water,acidic,products,such,HF,Therefore,boosting,provide,promising,enhancing,industrialization

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