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	{{chembox		{{chembox
			| ImageFile=Tetrahydridoboritan lithný.png
⚫	| verifiedrevid = 402202930
			| ImageFile1=]]
		⚫	| ImageFile2=File:Lithiumborhydrid.png
			| ImageSize2 = 250px
			| ImageCaption2 = Unit cell of lithium borohydride at room temperature
			| ImageAlt2 = Unit cell of lithium borohydride at room temperature
			| Watchedfields = changed
		⚫	| verifiedrevid = 421092672
	| IUPACName = Lithium tetrahydridoborate(1–)		| IUPACName = Lithium tetrahydridoborate(1–)
	| OtherNames = Lithium hydroborate,<br/>Lithium tetrahydroborate<br/>Borate(1-), tetrahydro-, lithium, lithium boranate		| OtherNames = Lithium hydroborate,<br/>Lithium tetrahydroborate<br/>Borate(1-), tetrahydro-, lithium, lithium boranate
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	| CASNo = 16949-15-8		| CASNo = 16949-15-8
	| CASNo_Ref = {{cascite|correct|CAS}}		| CASNo_Ref = {{cascite|correct|CAS}}
			| UNII_Ref = {{fdacite|correct|FDA}}
			| UNII = 8L87X4S4KP
	| PubChem = 4148881		| PubChem = 4148881
	| RTECS = ED2725000		| RTECS = ED2725000
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	| MolarMass = 21.784 g/mol		| MolarMass = 21.784 g/mol
	| Appearance = White solid		| Appearance = White solid
	| Density = 0.666 g/cm<sup>3</sup><ref name="Sigma-Aldrich"></ref>		| Density = 0.666 g/cm<sup>3</sup><ref name="Sigma-Aldrich">.</ref>
			| MeltingPtC = 268
	| MeltingPt = 275 °C<ref name="Sigma-Aldrich"/>
	| BoilingPt = 380 °C (decomp)		| BoilingPtC = 380
			| BoilingPt_notes = decomposes
	| Solubility = reacts		| Solubility = reacts
	| SolubleOther = 2.5 g/100 mL		| SolubleOther = 2.5 g/100 mL
	| Solvent = ]		| Solvent = ]
	}}		}}
	| Section3 = {{Chembox Thermochemistry		| Section3 = {{Chembox Structure
			| Structure_ref =<ref>{{cite journal |author=J-Ph. Soulie, G. Renaudin, R. Cerny, K. Yvon |title=Lithium boro-hydride LiBH<sub>4</sub>: I. Crystal structure |doi=10.1016/S0925-8388(02)00521-2 |journal=] |volume=346 |issue=1–2 |date=2002-11-18 |pages=200–205}}</ref>
⚫	| DeltaHf = -8.759 kJ/g
			| CrystalStruct = orthorhombic
			| SpaceGroup =
			| PointGroup = Pnma
			| LattConst_a = 7.17858(4)
			| LattConst_b = 4.43686(2)
			| LattConst_c = 6.80321(4)
			| LattConst_alpha =
			| LattConst_beta =
			| LattConst_gamma =
			| LattConst_ref =
			| LattConst_Comment =
			| UnitCellVolume = 216.685(3) A<sup>3</sup>
			| UnitCellFormulas = 4
			| Coordination = B
			| MolShape =
			| OrbitalHybridisation =
			| Dipole =
			}}
			| Section4 = {{Chembox Thermochemistry
		⚫	| DeltaHf = −198.83 kJ/mol
	| DeltaHc =		| DeltaHc =
	| Entropy =		| Entropy = 75.7 J/(mol⋅K)
	| HeatCapacity = 3.792 J/g K		| HeatCapacity = 82.6 J/(mol⋅K)
	}}		}}
	| Section4 = {{Chembox Hazards		| Section5 = {{Chembox Hazards
	| MainHazards =		| MainHazards =
	| FlashPt =		| FlashPt =
	| Autoignition = > 180 °C		| AutoignitionPt = >
			| AutoignitionPtC = 180
	}}		}}
	}}		}}
	'''Lithium borohydride''' (LiBH<sub>4</sub>) is a ] and known in ] as a ] for ]s. Although less common than the related ], the lithium salt offers some advantages of being highly soluble in ethers and being a stronger reducing agent but still safer to handle than ].		'''Lithium borohydride''' (LiBH<sub>4</sub>) is a ] and known in ] as a ] for ]s. Although less common than the related ], the lithium salt offers some advantages, being a stronger reducing agent and highly soluble in ethers, whilst remaining safer to handle than ].<ref name=eros>Luca Banfi, Enrica Narisano, Renata Riva, Ellen W. Baxter, "Lithium Borohydride" e-EROS Encyclopedia of Reagents for Organic Synthesis, 2001, John Wiley & Sons. {{doi|10.1002/047084289X.rl061.pub2}}.</ref>
	==Preparation==		==Preparation==
	Lithium borohydride may be prepared by the ], which occurs upon ball-milling the more commonly available ], and ]:<ref>Peter Rittmeyer, Ulrich Wietelmann “Hydrides” in Ullmann's Encyclopedia of Industrial Chemistry, 2002, Wiley-VCH, Weinheim. {{DOI|10.1002/14356007.a13_199}}</ref>		Lithium borohydride may be prepared by the ], which occurs upon ball-milling the more commonly available ] and ]:<ref>Peter Rittmeyer, Ulrich Wietelmann, "Hydrides" in Ullmann's Encyclopedia of Industrial Chemistry, 2002, Wiley-VCH, Weinheim. {{doi|10.1002/14356007.a13_199}}.</ref>
	: NaBH<sub>4</sub> + LiBr &rarr; NaBr + LiBH<sub>4</sub>		: NaBH<sub>4</sub> + LiBr → NaBr + LiBH<sub>4</sub>
			Alternatively, it may be synthesized by treating ] with ] in ]:<ref name="Georg">{{cite book |last=Brauer |first=Georg |title=Handbook of Preparative Inorganic Chemistry |volume=1 |edition=2nd |date=1963 |publisher=Academic Press |location=New York |isbn=978-0-12-126601-1 |page=775 |url=https://books.google.com/books?id=TLYatwAACAAJ&q=Handbook+of+Preparative+Inorganic+Chemistry}}</ref>
			: BF<sub>3</sub> + 4 LiH → LiBH<sub>4</sub> + 3 LiF
	==Reactions==		==Reactions==
			Lithium borohydride is useful as a source of ] (H<sup>–</sup>). It can react with a range of ] substrates and other polarized carbon structures to form a hydrogen–carbon bond. It can also react with ]-acidic substances (sources of H<sup>+</sup>) to form ] gas.
	Lithium borohydride reacts largely like ], in that it is a hydride-donating reducing agent in organic synthesis. It is however a stronger reducing agent. Unlike the sodium salt, lithium borohydride reduces esters and amides to the corresponding alcohols and amines.
			===Reduction reactions===
			As a ] reducing agent, lithium borohydride is stronger than sodium borohydride<ref>{{cite book |editor1-last=Trost |editor1-first=Barry |editor2-last=Fleming |editor2-first=Ian |editor3-last=Schreiber |editor3-first=Stuart |last1=Barrett |first1=Anthony G.&nbsp;M. |chapter=Reduction of Carboxylic Acid Derivatives to Alcohols, Ethers and Amines |title=Reduction: Selectivity, Strategy & Efficiency in Modern Organic Chemistry |date=1991 |publisher=Pergamon Press |location=New York |isbn=978-0-08-040599-5 |page=244 |edition=1st |doi=10.1016/B978-0-08-052349-1.00226-2}}</ref><ref name=chemoselective>{{cite journal |last1=Ookawa |first1=Atsuhiro |last2=Soai |first2=Kenso |title=Mixed solvents containing methanol as useful reaction media for unique chemoselective reductions within lithium borohydride |journal=The Journal of Organic Chemistry |date=1986 |volume=51 |issue=21 |pages=4000–4005 |doi=10.1021/jo00371a017}}</ref> but weaker than lithium aluminium hydride.<ref name=chemoselective /> Unlike the sodium analog, it can reduce esters to alcohols, ]s and ] ]s to ]s, and can open ]s. The enhanced reactivity in many of these cases is attributed to the polarization of the carbonyl substrate by complexation to the lithium cation.<ref name=eros/> Unlike the aluminium analog, it does not react with ]s, ]s, ], or ] and ] amides.
			===Hydrogen generation===
			Lithium borohydride reacts with water to produce hydrogen. This reaction can be used for hydrogen generation.<ref>{{cite journal |first1= Yoshitsugu |last1= Kojima |first2= Yasuaki |last2= Kawai |first3= Masahiko |last3= Kimbara |first4= Haruyuki |last4= Nakanishi |first5= Shinichi |last5= Matsumoto |title= Hydrogen Generation by Hydrolysis Reaction of Lithium Borohydride |journal= ] |volume= 29 |issue= 12 |pages= 1213–1217 |date= August 2004 |doi= 10.1016/j.ijhydene.2003.12.009}}</ref>
			Although this reaction is usually spontaneous and violent, somewhat-stable ]s of lithium borohydride can be prepared at low temperature if ], ] is used and exposure to ] is carefully avoided.<ref>{{cite journal |title= Preparation of Quaternary Ammonium Borohydrides from Sodium and Lithium Borohydrides |first1= M. Douglas |last1= Banus |first2= Robert W. |last2= Bragdon |first3= Thomas R. P. Jr |last3= Gibb |journal= J. Am. Chem. Soc. |year= 1952 |volume= 74 |issue= 9 |pages= 2346–2348 |doi= 10.1021/ja01129a048 }}</ref>
	==Energy storage==		==Energy storage==
			]]]
	]		]
	Lithium borohydride is renowned as one of the highest ] chemical energy carriers. Although presently of no practical importance, the solid will liberate 65 ] heat upon treatment with atmospheric oxygen. Since it has a density of 0.67 ], oxidation of liquid lithium borohydride gives 43 ]. In comparison, gasoline gives 44 MJ/kg (or 35 MJ/L), while liquid hydrogen gives 120 MJ/kg (or 8.0 MJ/L).<ref name="LH2" group="nb">The greater ratio of energy density to specific energy for hydrogen is because of the very low mass density (0.071 g/cm<sup>3</sup>).</ref> The high specific energy density of lithium borohydride has made it an attractive candidate to propose for automobile and rocket fuel, but despite the research and advocacy it has not been used widely. As with all chemical-hydride-based energy carriers, lithium borohydride is very complex to recycle (i.e. recharge) and therefore suffers from a low ]. While batteries such as ] carry an energy density of up to 0.72 MJ/kg and 2.0 MJ/L, their ] to DC conversion efficiency can be as high as 90% {{Citation needed|date=June 2010}}. In view of the complexity of recycling mechanisms for metal hydrides,<ref>US Patent 4002726 (1977) lithium borohydride recycling from lithium borate via a methyl borate intermediate</ref> such high energy conversion efficiencies are beyond practical reach.		Lithium borohydride is renowned as one of the highest-] chemical ]s. Although presently of no practical importance, the solid liberates 65&nbsp;]/] heat upon treatment with atmospheric oxygen. Since it has a density of 0.67&nbsp;], oxidation of liquid lithium borohydride gives 43&nbsp;]. In comparison, gasoline gives 44&nbsp;MJ/kg (or 35&nbsp;MJ/L), while liquid hydrogen gives 120&nbsp;MJ/kg (or 8.0&nbsp;MJ/L).<ref name="LH2" group="nb">The greater ratio of energy density to specific energy for hydrogen is because of the very low mass density (0.071&nbsp;g/cm<sup>3</sup>).</ref> The high specific energy density of lithium borohydride has made it an attractive candidate to propose for automobile and rocket fuel, but despite the research and advocacy, it has not been used widely. As with all chemical-hydride-based energy carriers, lithium borohydride is very complex to recycle (i.e. recharge) and therefore suffers from a low ]. While batteries such as ] carry an energy density of up to 0.72&nbsp;MJ/kg and 2.0&nbsp;MJ/L, their ]-to-DC conversion efficiency can be as high as 90%.<ref>Valøen, Lars Ole and Shoesmith, Mark I. (2007). The effect of PHEV and HEV duty cycles on battery and battery pack performance (PDF). 2007 Plug-in Highway Electric Vehicle Conference: Proceedings. Retrieved 11 June 2010.</ref> In view of the complexity of recycling mechanisms for metal hydrides,<ref>{{US Patent|4002726}} (1977) lithium borohydride recycling from lithium borate via a methyl borate intermediate.</ref> such high energy-conversion efficiencies are not practical with present technology.
			{{clear left}}
	{| class="wikitable" style="text-align:center"		{| class="wikitable" style="text-align:center"
	|+ Comparison of Physical Properties		|+ Comparison of physical properties
	|-		|-
	! Substance !! ] ] !! ] ] !! ] ]		! Substance !! ],<br/> ]/] !! ],,<br/> ] !! ],<br/> ]
	|-		|-
	! '''LiBH'''<sub>4</sub>		! LiBH<sub>4</sub>
	| 65.2 <!-- from text -->		| {{0}}65.2{{0}} <!-- from text -->
	| 0.666 <!-- from text, matches back-calculation -->		| 0.666{{0}} <!-- from text, matches back-calculation -->
	| 43.4 <!-- from text -->		| 43.4 <!-- from text -->
	|-		|-
	! Regular ]		! Regular ]
	| 44 <!-- from ] -->		| {{0}}44{{0|.00}} <!-- from ] -->
	| 0.72 <!-- value from ]. Back-calculated from text gives 0.659. Conversely, back-calculated from these values give 0.79 -->		| 0.72{{0|00}} <!-- value from ]. Back-calculated from text gives 0.659. Conversely, back-calculated from these values give 0.79 -->
	| 34.8 <!-- from ] -->		| 34.8 <!-- from ] -->
	|-		|-
	! ]		! ]
	| 120 <!-- from text -->		| 120{{0|.00}} <!-- from text -->
	| 0.0708 <!-- from text, matches back-calculation. ] gives very similar 0.709 -->		| 0.0708 <!-- from text, matches back-calculation. ] gives very similar 0.709 -->
	| 8 <!-- from text -->		| 8 <!-- from text -->
	|-		|-
	! ]		! ]
	| 0.72 <!-- from text -->		| {{0|00}}0.72 <!-- from text -->
	| 2.8 <!-- back-calculated from text-->		| 2.8{{0|000}} <!-- back-calculated from text-->
	| 2 <!-- from text -->		| 2 <!-- from text -->
	|}		|}
	==See also==		==See also==
	*]
	*]
	*]		*]
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